Kuznetsov E. N., Lunin V. Y., Panyushkin A. V., Chernyshev I. L. Boundaries of non-separation flow-around of bodies of rotation, with the nose part in the form of Riabouchinsky half-cavity. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 7-15. Bodies that are optimal at the so-called low critical Mach number M*, at which at least one sonic point on the body flown-over surface occurs, were studied theoretically in Ref. [1]. It was confirmed that M* achieves its maximum value and, consequently, the wave drag minimum value occurred for the body identical to the Riabouchinsky finite cavity in the classical theory of incompressible fluids. It was experimentally studied in Ref. [12], which demonstrated that in the transonic velocities range the Riabouchinsky half- cavity had the smallest drag among the bodies of rotation with the same aspect ratio λ=L/D=0.87(where L is the nose part length and D is the diameter of its mid-section). This conclusion is incorrect for aspect ratios λ>2 due to the friction impact the drag as it follows fr om Ref. [24]. The absence of turbulent boundary layer separation from the side surface of the body of rotation under study at zero angle of attack in the range of Mach numbers 0.8≤M∞≤0.95 was demonstrated in Ref [17].
The main objective of this work is determination of angles of attack αsep at which turbulent boundary layer separation from the side surface of the studied body occurs. The study was performed with NUMECA FINE/Open software based on Reynolds Averaged Navier-Stokes equations (RANS). The solution of the problem was performed in the framework of fully turbulent flow model without accounting for laminar-turbulent transition using Spalart-Allmaras (SA) and k-ω SST turbulence models. To determine the boundaries of the non-separated flow-around computation was performed in stationary problem setting at various angles of attack. With that, the flow separation indicator was the presence of the zone on the model surface wh ere the friction coefficient Cf < 0. The results obtained with two turbulence models are close to each other, and the difference between the two separation angles does not exceed 1°.
The results of the study obtained for αsep for the nose part with aspect ratio of are as follows: αsep=15° for М∞=0.5, αsep=9° for М∞=0.65, αsep=12° for М∞=0.8, αsep=13° for М∞=0.85, αsep=5° for М∞=0.9, αsep=11° for М∞=0.95. Computing results for the longer nose part with aspect ratio are: αsep=20° for М∞=0.5, αsep=13° for М∞=0.7, αsep=21° for М∞=0.9, αsep=18° for М∞=0.95.
The angles of attack αsep which realize turbulent boundary layer separation from the side surface of the investigated body at free-stream Mach numbers 0.5≤M∞≤0.95 were obtained. Separation zones location is shown for various models and modes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bragin N. N., Kovalev V. E., Skomorokhov S. I., Slitinskaya A. Y. On evaluation of buffeting of a swept wing with high aspect ratio at transonic speeds. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 16-27. The article presents to the development of a technique for buffet initialization boundary evaluation, occurring on a swept height aspect ratio wing at increasing angle of attack during cruising flight modes. The lift coefficient value of the buffet onset is one of the limitations that should be accounted for while designing the win aerodynamic layout of a subsonic aircraft. According to the norms, the margin between the cruise flight mode and the CLbuff value or the lift coefficient of the buffet onset should be at least 30%. Thus, knowing the CLbuff value through the entire operational speed range is a prerequisite for an aerodynamic wing configuration design beginning from the preliminary design stage. The problem of determining the CLbuff has become of special urgency at the transonic speeds due to the substantial aspect ratio increase of the (by 15–20%) of the long-range aircraft wings due to the composite materials application in load-carrying structure.
Despite the successes in CFD aerodynamics gained over the last years, non-stationary separation flow modes are studied, basically, using experimental tools, including wind tunnel tests of airplanes high scale models. Though the cost of such studies is high, they ensure required reliability of the obtained results. It is worth mentioning, that the time consuming computations on multiprocessor computers are costly as well. With this, the high accuracy and reliability of the obtained results are not guaranteed. Preparing mathematical model and building-up computational meshes with hundreds of millions of nodes are commensurable with costs of developing and manufacturing scaled models for tests in the wind tunnel. Thus, numerical methods do not always prove to be less labor consuming and costly than the experimental ones. Despite the fact that computer facilities and software develop rapidly, and the situation gradually changes, experimental methods remain as before the basic tool while performing the studies of complex flows.
The article presents the analysis of typical features of the wing flow-around at the angles of attack corresponding to the start of the buffet mode. The technology of application of the program for computing transonic flow-around based on the full potential method for the buffet initialization computing is demonstrated. Computational results comparison with the data of experimental studies obtained for the model of the wing with fuselage in the wind tunnel is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilenko N. V., Kirenchev A. G. Vortex formation of gravity flows. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 28-36. Vortex formation analysis of the air medium as a gas turbine engine (GTE) propellant allows extracting one of its specifics, namely the gravity character of the technogenic vortices formation. The fudamentals of this vortex formation are being subordinated to the natural vortexes formation of the Earth atmospheric environment. The theory of technogenic vortices of the GTE operating on the ground, the same as the theory of natural atmospheric vortexes is being in the state of its development. It confirms the state of the issues of the working process principle and classification of both technogenic and natural vortices stated in scientific and technical literature and textbooks on the theory of gas turbine engines and metrology. The most informative is the database on meteorological studies of natural vortices (tornados, cyclones, circulations and atmospheric fronts). Thus, due to the technogenic and natural gravity vortex forming similarity, the gist of technogenic vortices' work process should be searched for in the gist of the cyclonic type vortices of the environment. The work process study herewith of the cyclonic type vortices (tornados and others) may be the basis for creating a theory of natural vortex forming.
The problem is set to study the work process of small-sized technogenic vortices with their subsequent adaptation to the work process of natural vortex forming.
The above said problem should be solved relying on the basic equations of gas dynamics (gas flow energy preserving and other) with subsequent yield to the methodology and essence of the gravity type vortices' work process. The most accessible to learning the gravity vortex formation and its vorticity is the energy conservation equation, including its components in the form of internal and kinetic energy of a gas flow, kinetic energy of the environment angular rotation, and heat exchange elements in the form of external mechanic work and heat. Hence, extracting the master unit of vortex formation (angular rotation energy) allows establish functional dependence of the vortex formation under study from the sources of energy capable of generating gravity vortices of various types.
The article presents the methodology of studying, and analysis of the problems of work process cognition of vortex movement of the Earth's ambiences. Classification of vortices according to the gist of their work process. The article indicates the way of splitting the vortex formation into the vortices according to the gist of the work process included into its classification, and further cognition of their physical entity and exploration resulting in vortex characteristics, their consequences and application areas. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yudintsev V. V. Rotating space debris objects net capture dynamics. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 37-48. By now, several methods for near Earth orbits active cleaning from large-size space debris were suggested. The most difficult stage of such mission is the stage of space debris capture. Capturing method selection and subsequent orbital transportation of space debris depends on its type and angular motion. Rockets' orbital stages may rotate with high angular velocity, which aggravates their capture by manipulators and other means. One of prospective techniques of such object capture is application of a net connected with the space tug by a tether. The object capture by a net can be performed by the net separation with a certain relative speed in relation to the space tug and space debris, or by the net unrolling on the trajectory of the space debris object relative to the space tug. Elastic properties of the net and tether allow reduce the load acting on the space tug while an object capturing process and control the value of this impact.
The paper presents discrete mathematical model of the net movement as a system of material points' elastic interaction, as well as these components interaction with the space debris surface. The possibility of capturing an orbiter type object, rotating with significant angular velocity was demonstrated through this model. The article demonstrates that capturing the object, rotating with angular speed of 5 degrees per second, requires the speed of the net relative to the space debris from 2 to 5 m/s. To capture an object, rotating with angular speed of 30 degrees per second, the net speed should be no less than 10 m/s. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bolsunovskii A. L., Bondarev A. V., Gurevich B. I., Skvortsov E. B., Chanov M. N., Shalashov V. V., Shelekhova A. S. Development and analysis of civil aircraft concepts employing integration principles. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 49-63. The search for the technologies allowing significantly improve operational characteristics of the prospective civil aircraft was the goal of the work.
The study of innovative technologies, including those, providing the airframe and engine integration, was performed applying methods of alternatives analysis, based on the factorial analysis, and experiments planning assuming performing a series of computing experiments with subsequent comparison of their results.
Three possible innovations trends were considered:
– application of a turbojet engine with the increased bypass ratio for the fuel consumption and noise-at-terrain reduction;
– application of the so-called distributed power plant with the separated gas generator and the fan connected by mechanical transmission;
– airframe and power plant elements integration for obtaining useful effects in aerodynamics and structure, as well as and obtaining new operational properties.
According to these independent principles a number of the long-haul aircraft possible configurations, differing by various combinations of the bypass ratio, the turbojet schemes and technologies of elements integration into the “airframe + engine” system was developed. The number of possible strategies of the integral aircraft, including the base option, corresponds to the number of binomial coefficient of the three factors 23 = 8 according to performing the full-factorial experiment.
A multidisciplinary expert assessment of aircraft configuration options was performed, which turned into the basis for the most effective concepts selection.
Comparison of possible characteristics revealed that some options of airframe and engine integration under consideration had potential for considerable of fuel consumption reduction compared to the conventional long-haul aircraft configuration. The results of the study allow recommend two strategies for further studies. These strategies also possess potential for additional improvement of the other operational characteristics, such as noise-at-terrain and operating safety. Other configurations possess a number of useful elements that can find application while critical technologies development and reduction of technical risks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Egoshin S. F. Impact evaluation of multi-propeller wing blow-over system on the stol aircraft characteristics. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 64-76. The article undertook the attempt to obtain an analytical solution to compute the take-off length of an aircraft equipped with the multi-propeller wing blow-over installation, and estimate the benefits of such engineering decision through the transport operation evaluation of this aircraft.
The main difficulty of this problem lies in the fact that the wing and propeller interaction is an extremely complex and insufficiently studied task. Currently, only approximate semi-empirical formulas for calculating the aerodynamic characteristics of the wing at small relative diameters of the blowing airscrew exist. The exact calculation of the wing flow-around in this case is possible only for strictly specified, nonparametric configurations using the finite-difference method.
In addition, the current complicated situation in the sphere of local air transport in Russia (reduction of airlines and operating airfields) requires the search and evaluation of effective technical solutions for a prospective aircraft of local airlines. One of the ways is envisaged as developing a short takeoff and landing (STOL) aircraft capable of carrying out transport operations in conditions of an underdeveloped airfield infrastructure. It is considered that equipping such a STOL airplane with a multi-propeller electrically powered blow-over system will be an effective solution to the problem. However, the above said complex aerodynamic task does not allow a quick search for the optimal characteristics of this aircraft.
The developed mathematical model, under certain constraints, allows obtain an evaluative analytical solution for the take-off run length of such STOL aircraft, reveal the specifics of parameters interaction and evaluate possible advantages and disadvantages of the aircraft. Within the framework of the model, it was demonstrated that the maximum possible power consumption from the main engines is the optimal value of the corresponding parameter of the electric power plant. The amount of this power consumption determines the blown part of the wing area through the relationship with the critical rotation speed of the auxiliary propellers.
As for performance of a transport STOL aircraft based on L-410, it was shown that a blow-over system based on conventional electrotechnical materials can reduce the take-off run by 30% (up to 300 m), while reducing the payload by 1520% at flight ranges up to 300 km or up to 50% when flying to the maximum range. At the same time, if the electric power plant is designed based on high-temperature superconductors (HTSC), the payload reduction will be much less: negligible at flight distances up to 300 km or about 25% with flight to the maximum range. This allows conclude that the HTSC technology application for such STOL aircraft creation is rather promising. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lopatin A. A., Nikolaeva D. V., Gabdullina R. A. Experimental data generalization on heat transfer in cooling system with axial sectional finning in conditions of free convection. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 77-85. At present, power electronic components with high heat release have been widely applied in various fields of modern industry. The main problem the developers of the element base are facing consists in creating cooling and thermal stabilization systems capable of removing heat fluxes of high density, while working in a wide range of ambient temperatures. When creating such systems, it is necessary, alongside with the thermal ones, to account for the mass-size characteristics of the device as a whole. Thus, much depends on the heat transfer intensification method selection.
Quite enough attention is paid in modern literature to the issues of radio electronic equipment thermally loaded elements, as evidenced by a significant number of articles and monographs on this topic. Heat release is one of the main causes of the unstable operation of radio electronic equipment. Among the basic factors exerting maximum destructive effect, the increased temperature of the elements is one of the main ones. Thus, the devices operation in the field of the radio electronic equipment is closely associated with heat removal from the thermally loaded components. Depending on the structure and shape of the cooled components, various solutions are employed for organizing continuous heat removal.
Certain problems of large heat fluxes removing in the elements of industrial electronic equipment were considered in [1-3]. The correct choice of the cooling system type ensures trouble-free operation of all cooled components of the device.
A considerable amount of publications in modern scientific publications, both in Russia and abroad, attest to the considerable interest in the issues related to the heat transfer intensification for surfaces of various shapes and sizes as applied to cooling systems for electronic equipment. The issues of heat transfer intensification are set forth in [4-10]. In particular, the criterion equations of various authors for the Nusselt number computing for natural convection are presented in [2, 9]. Experimental studies of the convective heat transfer intensification in rectangular dissected channels and in channels with discrete turbulators were described in [1, 10]. In the studied dissected channels, a process of rational convective heat transfer intensification was implemented, reliably controlled by changing the values of the basic dimensionless geometric parameters. The generalizing dependences for discrete-rough channels were obtained in [7] for free convection conditions, and flow modes and mechanisms of intensification were studied. In [11-14], the authors experimentally studied one of the parameters characterizing the cooling systems both qualitatively and quantitatively, namely, the thermal resistance.
The fins application as a method of heat transfer intensifying leads to the increase in the heat transfer coefficient value by a factor of tens. This method of intensification implies a wide variety of vatious types of fins, such as: longitudinal, transverse, rolling, spiral and many others [15,16]. In [15] the analysis of the expediency of employing different types of fins from the viewpoint of the coolant aggregate state is presented. The optimal edges number selection is presented in [16]. The heat transfer intensification of the systems with a cut-off fin is also considered in [17-20].
The purpose of this work consists in studying the efficiency of the split finning under conditions of natural convection. A test bench was developed for performing the experiment on the study of heat transfer. While the experiments on heat transfer near the cut edge under conditions of natural convection, criterion dependencies were obtained.
Relying on the analysis of literature sources and accounting for the results obtained while experimental studies, the authors established that from the viewpoint of the of axial split finning practical applicability, there are a number of specifics, associated primarily with the fact that the “petals”, obtained as a result of dissection of the heat exchange surface, can be considered as independent ribs. The studies of heat transfer intensification under conditions of natural convection with the cut ribs application were conducted and presented as a result of the work. While the experiment, the effectiveness of the use of split finning is demonstrated, and the most optimal geometric parameters of the working area were revealed. The process of heat transfer was visualized. The boundary layer thickness near the cut edge was computed. Criterion dependencies for heat transfer computing of the systems with axial cut fins were obtained. The prospect of this study is of experimental data verification by numerical modeling programs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zichenkov M. C., Ishmuratov F. Z., Kuznetsov A. G. Studying the gyroscopic forces and structural damping joint impact on the wing flutter of the aeroelastic euram model. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 86-95. The article deals with the structural damping role analysis while studying the gyroscopic forces impact on the flutter speed. The algorithm for accounting for gyroscopic forces in polynomial Ritz method while computing the aircraft aeroelasticity dynamic characteristics, developed earlier by the authors, was employed. The algorithm was realized in the KC-M software developed in TSAGI and validated while solving aeroelasticity problems in many practical applications. The computations were performed on the example of the wing of the well-known aeroelastic research model of the four-engine long-distance aircraft EuRAM (European Research Aeroelastic Model), developed and studied in the framework of the European project 3AS (Active Aeroelastic Aircraft Structure). The model characteristic feature is the flutter form occurrence associated with the lateral vibrations of external engines. This form is affected by the gyroscopic forces due to the engines rotating rotors.
The flutter characteristics analysis at various levels of structural damping (characterized by logarithmic vibrations decrement δ ) revealed that the vibrations tones interaction character with account for gyroscopic effect was not principally changed. It was found herewith, that the gyroscopic forces impact on the speed of the considered flutter form might be of different sign depending on the level of the structural damping.
For example, at δ = 0.02 the flutter speed increases by 11.5%, with the maximum value of the engine rotor kinematic momentum (scaled to the model). While increasing the structural damping value, in the beginning, the gyroscopic forces' impact on the flutter speed decreases, it does not practically exist at δ = 0.04, and with further increase of the decrement the impact changes its sign, and the flutter speed decreases. The flutter absence was marked at δ > 0.046 in the range of small rotor rate speed, but while the rate speed increase the flutter may occur. Its speed decreases at that (about 10%) with the rate speed increase. This indicates the importance of accounting for the dynamics of rotor systems while the aircraft aeroelastic phenomena analysis.
The obtained the results were confirmed also by the finite element computing method in NASTRAN system using Rotordynamics module (accounting for the rotor systems dynamics). The computing results on gyroscopic forces impact on aeroelasticity characteristics at various structural damping values performed with KC-M software accord well with computations performed with NASTRAN software.
It was noted that while experimental validation of the gyroscopic impact on the flutter speed of the model in the wind tunnel various results might be obtained depending on the structural damping level. Thus, the detailed computational and experimental analysis of the model dynamic characteristics is required while such tests preparing and running. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezrokhi Y. A., Kalenskii S. M., Morzeeva T. A., Khoreva E. A. Analysis of a concept of the distributed power plant with mechanical fans drive while integration with a “flying wing” type flying vehicle. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 96-109. The article presents analysis of a concept of the distributed power plant (DDP) while its integration with a “flying wing” type flying vehicle.
A modified airframe model of a prospective long-range aircraft (LRA) of PJSC “Tupolev” development with two power plants integrated into the tail-end was selected as a flying vehicle.
Those power plants represent a bypass turbojet engine where two taken-out fan modules are driven by mechanical transmission from fan turbine of this turbojet. The choice in favor of a mechanical way of power transfer for the aircraft of 2030 level is based on the results earlier performed studies on the engines of new schemes in CIAM named after P.I.Baranov.
The results obtained while numerical modeling of the flow on the upper surface of an LRA airframe were also employed. This modeling revealed that for a long-range flight the mean values of the full pressure's losses prior to the fans differed greatly and depended monotonously on the flow deceleration level in the air intake. According to the calculations, the average value the full pressure restoration coefficients was correspondingly ~0,923 for the first fan module, ~0,952 for the bypass turbojet and ~0,958 for the second fan module.
Refining of the earlier developed model of the distributed power plant was performed to evaluate the impact of the conditions at the inlet of each of fan modules. The performed of mathematical model refinement allowed implementing independent selection of parameters, dimensionality and gear-ratios of reducing gear for DPP fan modules drive, as well as performing independent regulation of output devices of these modules.
The article considers separately the impact of the two main factors on the engine thrust, namely, the fall of the full presure level at the inlet, and its proper heterogeneities.
Calculations revealed that for the earlier selected DPP option while its integration into the flying vehicle under consideration, regulation of nozzles of the turbojet bypass loop and fan modules was required at the cruising mode. With this, gas temperature increase prior to the turbine by ~70 К was required.
Three different variants of the engine which allow excluding the above said regulation were investigated while this work.
The first variant is a version with fans equal by dimensionality and pressure ratio at the designed cruising mode.
The second variant is a version with the first fan module with the pressure ratio increased by 5% relative to the BTJEs fan at the cruising mode.
The third variant is a version with first fan module air consumption decreased by 50% at the cruising mode.
Parametric studies performed employing the develop methodology allowed selecting the degree of bypassing and the degree of pressure increase in the fan optimal by the specific fuel consumption at the cruising mode for each DPP option. The dimensionality of fan modules and main DPP units was refined with account for various losses levels at the inlet.
Analysis of effects associated with the presence of a non-uniform field of the full pressure and leading to its average level decrease at the fan inlet revealed that impact of the presence of non-uniformity might be from 15 to 30% of total impact on the engine thrust.
At the same time, while the power plant parameters selection at the cruising mode with account for the degraded coefficients of the full pressure preservation prior to the fan, the fall of the thrust level due to the proper non-uniformity might be ~2,53% at the given mode. This should be accounted for while selecting an optimal DPP appearance of the configuration under consideration. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panov S. Y., Kovalev A. V., Aisin A. K., Achekin A. A. Aircraft air intakes location impact on vortex formation intensity. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 110-119.
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Kalugin K. S., Sukhov A. V. Methane application specifics as a fuel for liquid rocket engines. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 120-132. At present, a significant part of the research aimed at increasing the energy and mass characteristics of liquid-propellant rocket engines (LPRE) is being performed in the field of new materials application and processing technologies. Other studies are aimed at modernizing the principle of organizing the work process. However, new fuels application is a more long-term and quickly realizable prospect notwithstanding the research costliness in the field of LPRE. Methane may appear one of the propellants, which application may become a new stage in rocket and space industry development. The article considers the historical process of methane formation as a liquid rocket fuel component since it was firstly mentioned by Tsiolkovsky in his works (“Exploration of the World Spaces with Jet Devices”, “Space Rocket”, “Jet Airplane”, “Achieving the Stratosphere”, etc.). A comparative analysis of methane with kerosene was performed in view of the similarity of the work process organization in the LPRE combustion chamber, as well as close hydrocarbon structure. A component close to methane, currently in use in rocket engines, is hydrogen due to the cryogenic nature of both components, which creates difficulties at the design stage of valves, pipelines and gas lines, as well as the organization of the work process in the combustion chamber. Additionally, analysis of the most common fuels based on kerosene, methane and hydrogen was performed. This is especially interesting, since methane fuel pair of oxygen-methane occupies an intermediate position between “oxygen-kerosene” and “oxygen-hydrogen” pairs with respect to the specific impulse and fuel mixture density. The analysis was performed based on physical-chemical, energy, operational, environmental, economic and some other characteristics. This allowed identify the main advantages and disadvantages of methane application as a LPRE fuel and determine its prospects both in Russian and foreign rocket and space industries.
A brief analysis of liquid rocket engines on methane, created or projected in NPO Energomash by V.P. Glushko, KBHA them. S.A. Kosberg, KB Himmash them. A.M. Isaev, the Research Center. M.V. Keldysh, and also to the American firm SpaceX.
Finally, it was concluded that the methane LPRE could replace oxygen-kerosene engines in the near future, since the fuel pair oxygen-methane outperformed the oxygen-kerosene pair by its energy, environmental and economic indicators. Interplanetary flights can become a special field of methane application, since a large amount of methane, the main element of natural gas, can be found almost everywhere in the solar system: on Mars, Titan, Jupiter and many other planets and satellites, which will allow refueling rockets in flight, significantly increasing them the flight range. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuz'michev V. S., Omar H. H., Tkachenko A. Y. Effectiveness improving technique for gas turbine engines of ground application by heat regeneration. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 133-141. The requirements for the ground based gas turbine installations efficiency improvement are constantly increasing.
Heat conversion into work in gas turbine engines, operating by the Brayton cycle, is attended by significant losses, which depend on the cycle parameters and reach up to 60-70% or more. At present, high-tech aircraft engines and their modifications are widely used as ground-based gas turbine plants, making provision for the gas turbines efficiency improvement based on the of combined thermodynamic cycles application.
The article considers the schemes of gas turbine units (GTU) for ground application with combined cycles, allowing improve their efficiency. One of the ways for the gas turbine units cycle improving is heat regeneration of the exhaust gases by installing a heat exchanger at the turbine outlet where a part of the heat is transferred into the air behind the compressor. However, relative bulkiness and substantial weight of the heat exchanger (even of plate type) do not allow at present active application of this scheme in aviation, but it is widely employed in ground applications.
In the case of ground based gas turbine unit, heat exchangers are located in the exhaust chamber or tower behind a power turbine. Thermal ratio of the most widely used tubular heat exchangers is θ = 0.8-0.9, and plate- type heat exchangers are characterized by the thermal ratio of θ = 0.5-0.8.
It is obvious that the main parameters of the thermodynamic cycle of gas turbines unite, such as the gas temperature T*g and the compressor pressure ratio (π* kΣ ), as well as the parameters determining the working process of additional units (heat regenerators, steam turbine, etc.) of the combined installation play an important role in its efficiency improving. Comprehensive optimization of these cycle parameters is the main goal of the gas-turbine combined unit thermodynamic design.
Computer models of a gas turbine unit with combined thermodynamic cycles developed in the ASTRA SAE-system allowed solve the problems of nonlinear multi-criteria optimization of their operating parameters, determine the most rational schemes depending on the intended purpose and operating conditions of the gas turbine unit.
Russian Turbofan engine TRDDF RD-33 was selected as the basis for studying the heat regeneration impact on efficiency effectiveness. Its low pressure compressor was cut off to eliminate the bypass duct while converting it into ground based installation.
The following variation values of the cycle basic thermodynamic parameters were selected (π*kΣ = 15, 30, 45, 60 и T*g = 1200, 1500, 1800, 2100 K). The GTE module without exhaust gases heat regeneration and a GTE with exhaust gases heat regeneration were developed employing ASTRA computer program. The paper presents some results of the study on GTE efficiency improvement.
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Ogloblin D. V., Gorelov A. D., Voroshilin A. P., Zueva K. S. Automated testing system for technical diagnostics of spacecraft power supply systems. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 142-151. One of the urgent tasks at present consists in time reduction of flying vehicle launch preparation through introduction of new technologies, equipment and various kinds of tests based on computational experiments.
One of the most expensive types of aircraft is a spacecraft for various missions and tasks in the near-earth space and interplanetary flights. The main system of a spacecraft is the power supply system. Stringent requirements on external impact stability, and operability maintenance in emergency situations, since its failure results in the spacecraft loss. The power supply system preparation and testing is a major part of the testing program and it is performed employing rather labor-intensive methods.
One of the most interesting objects for the test complex optimization are the spacecraft for astronomical observations, as they present a set of a large number of complex technical devices for various purposes and control systems. Such aircraft requires a special approach to ensuring the quality of various electrical systems tests, as well as control and monitoring systems.
It is important to ensure uninterrupted power supply of the onboard service and scientific equipment for the timely data obtaining during the mission. Thus, the task of rapid and high-quality electrical tests performing of such spacecraft is of paramount importance.
The following core systems are being subjected to comprehensive electrical testing: the onboard radio telemetry system, onboard control system, propulsion system, the solar panels orientation system, power system, electrification control system.
Besides scientific equipment, these systems form the basis of almost any spacecraft. Due to the large number of systems subjected to electrical checks, the issue of the electrical tests time reduction, while preserving their quality (guaranteed reliability level of the systems) is relevant. It is necessary to determine the level of reliability and the number of tests based on the system model.
This above said problem can be solved by optimizing the measurement devices' number and functional characteristics, as well as application of automated measurement systems (AIC) for processing a large number of parameters (with account for specifics of electrical tests). This solution allows optimize the testing process, while reducing herewith the number of employed measuring equipment and the test program cost.
The upgraded AIC version allows combine system data into one subsystem of the power bus monitor. It also ensures centralized output of the test data to the Central computer, reducing the number of additional jobs, and simplifying the operators work.
The final layout option has a more optimized build structure. The structural diagram of the modernized automated testing system for electrical testing is presented.
Application of the reliability computation model allowed estimate the number of necessary checks, and the proposed system ensured the electrical tests duration reduction by 30%.
Implementation this complex of has increased the voltage, current and resistance parameters measurements accuracy by 0.01%.
This set allows define the parameters of voltage, as well as the leakage current and the signal occurrence at a specified time instant. This allows localize and fix the problem with the power supply during the test.
The software has a flexible customizable interface that allows quickly respond to changes and emergencies.
The proposed complex can be employed for spacecraft testing and, first of all, telecommunication satellites for various purposes based on of the “Navigator” platform. As examples of products using this platform, we can cite the spacecraft of the Arctic family, Electro and Spectrum. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sedel'nikov A. V., Puzin Y. Y., Filippov A. S., Khnyreva E. S. Soft hardware efficiency estimation for a small spacecraft rotation angular velocity provision and monitoring. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 152-162. The article presents the efficiency estimation of an AIST type small spacecraft rotation angular velocity provision and monitoring, employing the improved modification of the software hardware compared to the basic model, undergone flight tests as a part of the flight and trial samples of the “AIST” small spacecraft.
The article deals with magnetometer sensors application as a measuring tool for estimating the rotational motion parameters for various types of spacecraft.
The gist of the article is narrowed down to the fact that for there is no problem of mounting place selection for magnetometers and magnetic actuators (electromagnets) installation on the large-weight spacecraft and space stations. At the same time, for the small spacecraft this problem is topical in view of the impact of onboard scientific and supporting equipment together with magnetic devices of orientation hardware, while magnetic moment work out, on magnetometer sensors measuring data.
The article analyses in detail operation results of a number of devices, containing magnetometer sensors, as a part of various spacecraft types, such as “Foton” No 2,“AIST”, “AIST-2D”. The analysis results revealed that for “Foton” No 2 weighting 6546 kg, almost all deviations in magnetometer sensors measurements could be explained by the measurements instrumental error, while for the “AIST” series spacecraft weighting up to 50 kg the sensors readings demonstrated significant discord.
The authors conclude that the problem of magnetometer sensors' measurement data correctness for small spacecraft is specific due to the essentiality of the impact of scientific and supporting equipment operation, which arises from the dense layout of the payload in the inner space of a small spacecraft.
One of the ways of this problem solving may be the software hardware development, accounting for this impact for each normal operations mode of the equipment.
As an example of such solution, the article presents the software hardware installed on the “AIST-2D” small spacecraft. In the case of the “AIST-2D” small spacecraft, the discrepancies in estimating the angular velocities by two different magnetometer sensors were much lower than for “AIST” small spacecraft. This was achieved by the improvement of software hardware. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Donskov A. V. Analysis of modern evaluation and modeling methods of contingencies occurrence risks onboard a spacecraft. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 163-169. The purpose of the article consists in analysis of modern evaluation and modelling methods of contingencies occurrence onboard a spacecraft and substantiation of methods selection for their subsequent application in the process of operative flight control. The process of the aircraft flight control while contingencies occurrence onboard a spacecraft (time limitation for the decision making on contingencies parrying and their type, high dynamics of the processes flow, multicriteriality of the spacecraft current state, the presence of sources of uncertainty) was studied. The inference was drawn, that all considered methods of the onboard contingencies risks evaluation and modelling were not exhaustive. Depending of the current situation, any of the considered methods and on account of the problems being solved could be employed for the contingency risk occurrence onboard a spacecraft evaluation and modelling. The accumulated experience of flight control in manned astronautics revealed that the most interest was provoked by those methods of contingencies risks evaluation and modelling, which reflect the ways of their evolution and aftermath. The selection of the contingencies occurrence risks onboard a spacecraft methods (logic-linguistic and theory of fuzzy sets) is being substantiated by the fact that it allows develop scenarios of the contingencies occurrence onboard a spacecraft and prepare initial data for the decision making on contingencies parrying in case of uncertainty. Methods of contingencies occurrence risks onboard a spacecraft considered in the article may be implemented as tools both in the systems for decision making support on contingencies onboard a spacecraft parrying and in expert systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalev A. A., Tischenko L. A., Antipin M. A., Shakhovtsev M. M. Oxide film homogeneity provision on the surface of silicon monocrystal substrates while their thermal oxidation process. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 170-177. The article deals with the impact of the thermal oxidation process technological parameters, such as the work process temperature and the value of oxidizer reagents consumption, on the oxide film uniformity on the silicon substrate surface. It evaluates the heat-treatment furnace preheating temperature range by modelling in ANSYS with the specified boundary conditions. The homogeneity characteristic, being computed by Min-Max method, was used for homogeneity estimation. The type of silicon wafers under consideration satisfied the number of parameters, such as d = 100 mm, thickness 400 µm, the polished silicon emissivity ε = 0.89, silicon thermal conductivity λ = 31.2 W /(mK), silicon density ρ = 2.33 g / cm3. The preheating temperature range for an atmospheric thermal furnace with a silicon carbide boat is 550–700 °C. Increase in the oxide film distribution homogeneity over the silicon substrates surface due to the uniform distribution of the temperature field was observed as the result of simulation. As a consequence, chemical reactions were close in the intensity of the oxidation processes flow. Experimental validation of the homogeneity increase was obtained due to the thermal furnace boat preheating.
Optimal values of oxidant reagents (O2, H2O) consumption at temperatures of 1100, 1000 and 850 °С in the two-phase heating furnace (heating – dry oxidation, work process – wet oxidation) were obtained experimentally. These values allow producing wafers with high-quality silicon oxide (U < 1%).
The article gives technological recommendations on high-quality oxide film provision on the surface of monocrystal silicon wafers by furnace preheating and maintaining temperature between the thermal oxidizing processes, as well as oxidant reagents consumption values selection, allowing producing wafers with high-quality silicon oxide. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Na L. ., Zhefeng Y. ., Yi F. . Shock absorber using inward-folding composite tube and its application to a crew seat: numerical simulation. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 178-188. This paper presents an innovative energy absorber consisting of an inward folding of composite tube, which is cut axially and turned into the inner of the itself. There is no excess of composite fragments after the composites destruction, and the debris will fill in the inner part of tube to increase the energy absorption. The impact energy is absorbed mainly by the fibers fractures, as well as delamination and friction between composite tube and the cylinder wall of the cap. Impact tests were performed to study the energy absorption performance. To study the shock absorber effect on the shock-resistance of the helicopter crew seat, a four-degree-of-freedom nonlinear biodynamic model corresponding to 50th-percentile male occupant was developed. The simulation results revealed a good shock-absorber shock-resistance performance. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhuravlev S. V., Zechikhin B. S., Ivanov N. S., Nekrasova Y. Y. Analytical technique for magnetic field calculation in active zone of electric motors with superconducting excitation and armature windings. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 189-201. Creation of systems with electric motors application is complicated by the restricted potential for conventional electromechanical transducers characteristics upgrading, namely due to their low specific and voluminous power. In this regard, Russian and foreign scientists are working on creating apparatuses based on high-temperature superconductors (HTS), which, as the studies demonstrate, are capable of ensuring higher values of specific power. In particular, developments of superconductor electric motors for prospective all-electric aircraft, sea vessels electric propulsion and wind-driven power plants are renowned. The article presents the problem solution of computing magnetic fields distribution in the active zone and parameters of excitation and armature windings of electric motor based on high temperature superconductors and ferromagnetic yoke of rotor and stator. The above said problem can be reduced to computing of the magnetic field, created by periodical system of current coils, placed between the two cylindrical ferromagnetic areas under the following conditions: the ferromagnetic sections permeability is assumed infinite, and the motor is considered long enough. The current coils systems herewith may be both of various external and internal radiuses, and of equal ones. As a result, a technique based on Poisson and Laplace equations solution relative to vector magnetic potential was developed. The active zone complicated area of a motor herewith was represented as a set of simple homogeneous partial areas according to the harmonic analysis method. The obtained formulas bear general character and can be employed for the computing parameters of motors of various structural schemes. The proposed technique accounts for the superconductor critical parameters, including the transport current dependence on the external magnetic field; the number of pairs of poles, high-order harmonics impact; the number of slots per pole and q phase. This technique can be applied to the ring armature winding. The solution presented in the article allows determine the HTS motor basic parameters such as quiescent E.M.F., inductive resistance of the armature winding phase, power, weight, etc. HTS generator computing was performed using the obtained formulas. The size of the motor active zone was obtained in accordance with the above mentioned computations. Finite elements analysis of magnetic fields distribution was performed to verify the analytical calculations results and their correction. The obtained results testify the high accuracy of the developed technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bazhenov N. G., Filina O. A., Ozerova E. Y. Uniaxial gyrostabilizer application for the gyroscopic stabilization system in self-contained control systems. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 202. The proposed unit relates to the field of navigation technology. This type of gyroscopic devices is the simplest and low cost compared to a rotary gyroscope. Single-axis and dual-axis gyroscopes, widely used for movement direction determining, are wellknown, by now, both in civil and military spheres. The main disadvantage of the now-employed gyroscopes is a low speed of the oriented direction determining, reaching up to several minutes. The proposed gyrocompass allows significantly reduce the above said disadvantage and at the same time dramatically improve the accuracy in the “North-South” direction determining. It aims at improving accuracy and speed in the “North-South” orientation determining. This type of gyroscope is much simpler and low cost at commensurable accuracy compared to a rotary gyroscope. The article presents a kinematic scheme of the HS, which allows implement a twin-axis perturbation control method. With this, it allows achieving the required control dynamic characteristics; stabilization accuracy, and the kinematic moment values by selecting the appropriate transfer coefficients Its main property consists in the ability to hold fixed direction of the axis of rotation in space in the absence of the external forces impact on it. This gyroscopic device structure consists of a gyroscope with a rotor of a “brick" shape; communication on angular deviations through amplifiers; torque sensors; and standard stabilizing motors. Thus, the whole complexity of the device consists in the gyro rotor manufacturing, and float chambers in particular. The proposed unit operates in the following way. At the effect of the moment on one of the axes, the rotor gyroscopic moment appears. Pulsating signals along the perpendicular axis appear as well. Thus, there are two types of signals, which can be employed to stabilize the object containing the above said unit is installed. These findings are supported by the presented equations, where are expressions for the deviations on the two axes. The gyrostabilizer motion was considered in the mathematical model under condition that the values of the moment of inertia on the axes α and β , with account for the presence of additional inserts, would be expressed in the form: . Thus, the equations were composed with account for these expressions. The said unit allows find application in the aircraft automatic devices systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grachev N. N. Stability provision of electromechanical transducer characteristics in conditions of flight in the upper atmosphere. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 207-215. Scientific results obtained in the work are devoted to the issues of measurement reliability and accuracy of small, slowly changing parameters of low-density gas flows effecting an aircraft in the upper atmosphere. The main trend of the research consists in measuring the aerodynamic forces effecting a flying vehicle in a depleted gaseous environment Measured electric signals coming from primary transducers are often of a low level, sometimes reaching the values less than the noise and interference levels by several orders of magnitude. The most acceptable way of such processes measuring while reaching the specified metrological characteristics is electrochemical modulation (interruption) of the incident gas flow by choppers. It allows obtain the required large gain of the AC signal; easily separate the modulated beam signal from the non-modulated background signal, even if the beam density is lower than this of the background, as well as employ the signal accumulation, which increases the signal-to-noise ratio at the transducer output.
To determine the optimum frequency of electromechanical conversion and ensure the specified accuracy and stability of metrological characteristics, the author proposed employing the method of probabilistic investigation of the stability of the transducer output characteristic. The study of the characteristic's stability is based on the method of probabilistic stability research, ensuring the account for the random character of structural and electro-physical parameters deviations under the impact destabilizing factors and in conditions of mass production. The underlying method of moments allows obtaining the required accuracy with a small amount of computation.
To analyze the stability of the membrane-capacitor transducer transfer characteristic and sel ect the optimum frequency of the flow interruption, programs for computing the nominal values of the frequency response (AFC) and phase-frequency characteristics (PFC) of the transducer, the sensitivity of the response frequency and phase response to the specified parameters were developed. The program for computing the mathematical expectations and dispersion of manufacturing tolerances and temperature coefficients was developed based on the analysis of frequency dependencies of the transducer parameters coefficients effect on its transfer characteristic. Besides, the dependencies of the transducer transfer characteristic fr om temperature at the flow chopper operating frequency, as well as from the temperature change of the transducer membrane were computed.
Based on the measuring transducer transfer function representation in the form of polynomials ratio and analysis of its absolute sensitivity functions to the manufacturing tolerance, structural and electro-physical parameters, as well as destabilizing factors computing dependencies of the transducer transfer function for its stability evaluation and selection of optimal electromechanical conversion frequency were obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sychev Y. A., Kuznetsov P. A., Zimin R. Y., Soloveva Y. A. Problems of current and voltage high-order harmonics compensation in conditions of distributed generation. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 216-210. The main task of this article consists in improving parallel power active filters operation, with account for the networks with distributed generation specifics, and their operation processes modeling.
Micro-power grids, and the features of their control algorithms, have recently gained considerable attention in a wide range of research community. While the potential for increasing the efficiency, reliability and adaptability of the local grid is the most important motivation for their development, micro-energy systems, in turn, may be implemented to meet the growing demand for electric energy in numerous applications. Compared to the high-power energy systems, micro-energy systems can depend on non-inertial generators, such as photovoltaic batteries arrays, which are connected through inverters. Despite the lack of inertia and other micro-power grids properties, which cause certain difficulties in control, micro-energy systems are controlled better through new control laws, such as, those depending on distributed computations, rather than on centralized processors.
Thus, the distortions of the shapes of the current and voltage waveforms introduced by the high-order harmonic components from the nonlinear load can be supplemented by distortions from the sources of distributed generation and the units for their synchronization with the grid. Wind turbines are the most common renewable energy sources. So the parallel power active filters application is considered in the article for the purpose of compensation of the high-order harmonics, generated in association with their operation features. Currently, there are three most common types of wind generators:
1. Induction generators directly connected to the grid. It is an old concept with a mechanical transmission between the turbine and the generator. The generator operates in a rather narrow range of speeds (just above the synchronous one), the gearbox provides a more or less constant speed of the generator at highly differing wind speeds. The generator requires a considerable amount of reactive power, so often a capacitor bank is connected to it.
2. Synchronous generators with permanent magnets. Usually they are delivered in the kit with rectifiers and inverters. The generator is connected directly to the turbine, and it rotates at a low frequency. The generator is being excitated by magnets, and it is not regulated. The rectifier converts the generator voltage/current into DC. At constant voltage there is a capacitor (for smoothing pulsations and as a certain energy buffer). At the DC voltage side the bulk capacitor is present (for tripples smoothing and as an energy buffer). The DC voltage/current is converted thereafter into AC voltage/current by the inverter with 50 Hz frequency and specified characteristics. Everything is determined by the inverter control system. In fact, the rectifier-inverter is an original DC insertion (the like are employed at the borders between the countries, or for energy transmission over large distances).
3. Double fed induction generators. It is just an induction machine with a phase rotor. The stator of the machine is connected directly to the grid, and the rotor is connected via a rectifier-inverter.
It depends, on many respects, on the concrete case, how separate wind generators are combined into wind farms. However, interference is generated in any case, and an effective compensation system is necessary at each stage.
The parallel active filter circuit and developed mathematical model for the conditions of distributed generation and combined power supply were proposed. They allow efficiently compensate for various harmonic interferences in the grids with distributed generation due to the revealed dependence of the efficiency indices of high-order harmonics correction by the parallel active filter on the value of the supply grid internal resistance and the load node parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tereshkin V. M. Theoretical justification of the possibility of reducing vibrations of electromagnetic origin in a five-phase alternating current machine in comparison with a three-phase machine. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 229-239. Multiphase electric machines with an odd number of phases can become an alternative to three-phase machines in areas where a stable rotation speed within one revolution of the shaft is required, as well as other areas requiring highly reliable electric drives with low noise and vibration, for example in special ventilation systems and complexes .
The problem of formation of the resulting current of 3-phase and 5-phase windings, which are fed from the bridge converter, is considered in the work. A comparative analysis of the resulting currents is given from the point of view of the harmonic composition. In solving the problem, a classical approach was used with the use of the vector method.
It was found that the components of the phase currents of the 5-phase symmetrical winding form the 1st and 11th harmonics of the resulting forward current and the 9th harmonic of the reverse sequence.
The third and seventh harmonics of the phase currents do not form a rotating field; their temporal alternation does not coincide with the spatial alternation of phases. The 5th harmonic of the resulting current is absent; in the phase-current spectrum of a 5-phase symmetrical winding, the 5th harmonic component is not contained.
The components of the phase currents of the 3-phase symmetrical winding form the 1st and 7th harmonics of the resulting forward current, as well as the 5th and 11th harmonic of the reverse sequence.
The 3rd and 9th harmonics of the resulting current are absent, because in the phase-current spectrum of the 3-phase symmetrical winding, the 3rd and 9th harmonic components are not contained.
By harmonic composition, the resultant current of the 5-phase winding takes precedence over the resultant current by a 3-phase winding. This allows us to assume that within the period of the first harmonic (fundamental rotation frequency) in a 5-phase winding, the vibrations of electromagnetic origin will be less than for the three phase windings.
Experimental studies of prototypes of 5-phase and 3-phase synchronous machines made using identical magnetic systems have shown that the level of mechanical vibrations of a 5-phase machine is lower than that of a 3-phase machine. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rebrov S. G., Yanchur S. V., Faustov A. V., Filin S. V. Laminated lithium-ion cells with high specific characteristics. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 240-248. Lithium-ion batteries are widely employed for space applications due to a number of advantages compared to other electrochemical systems, especially due to their high specific energy and volume values. Laminated lithium-ion cells possess maximum specific characteristics among lithium-ion cells of other types (cylindrical and prismatic). Besides, they allow use available space more effectively. Despite skeptical attitude towards the laminated Lithium-ion batteries, however, there is information on their successful application in space conditions.
Keldysh Research Center is developing the space oriented Lithium-ion batteries with improved operational and specific characteristics. For example, Keldysh Research Center has already developed and tested the Lithium-ion battery for application in outer space conditions. The objective of the studies being performed is creation of the laminated Lithium-ion battery with improved specific characteristics, large calendar and cyclic life and a possibility to function in conditions of outer space. The task at this stage of the research work consists in searching for cathode and anode compositions allowing achieve maximum specific and volumetric parameters, as well as study electrical characteristics of these batteries under normal climatic conditions.
The studies conducted by Keldysh Research Center with cooperation of the Research Center of Applied Acoustics aiming at searching for cathode and anode composition allowed obtain maximum specific and volumetric parameters for laminated lithium-ion cells (often also called polymer Li-ion by mistake).
Two types of Lithiated oxide of Nickel-Manganese-Cobalt (NMC) and three types of Lithiated oxide of Nickel-Cobalt-Aluminum (NCA) were used as active cathode materials. Six different types of battery-grade carbons were used as active anode materials. N-methylpyrrolidone was used as a solvent for cathode slurries manufacturing, and water was used for anode manufacturing. As the studies revealed, the brand NCA A801-COA was the best choice as an active cathode material and carbon black brand AGP-2A was the best choice as an active anode material. The mass fraction of the active cathode material in the cathode mass was improved up to 93%; the fraction of the active anode material was improved up to 95%. Specific characteristics increase while manufacturing laminated batteries of high capacity. It indicates the batteries manufacturing flexibility while transferring from small-sized laboratory cells to large-sized experimental cells.
The obtained optimal electrodes compositions for Li-ion cells with rated capacity in the range of 1.6-15.3 A·h allow achieving the specific and volumetric values at the level of 230-268 W·h/kg and 520-560 W·h/lrespectively. The following characteristics were demonstrated herewith: for charge-discharge currents of 0.2C-0.2C the cyclability was about 1200 cycles with 97.75% efficiency; for charge-discharge currents of 0.2C-0.1C it was about 980 cycles with 87.8% efficiency, and for charge-discharge currents of 0.5C-1C the cyclability was about 460 cycles with efficiency of 89.1%. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rygina M. E., Petrikova E. A., Teresov A. D., Ivanov Y. F. Studying the possibility of hypereutectic silumin surface layer structure and properties modification by intense pulsed electron beam. Aerospace MAI Journal, 2018, vol. 25, no 4, pp. 248-256. Silumins of the hypereutectic composition in the cast state are characterized by a high level of porosity, the presence of large silicon inclusions and intermetallides, which significantly reduces the range of this material application in industry. To eliminate these drawbacks, samples of hypereutectic silumin (Al- (20-22) wt% Si) were irradiated in vacuum with an intense pulsed electron beam in the surface layer melting mode. Irradiation of the surface of the silumin samples was performed by an intense pulsed electron beam (“SOLO” facility, HCEI SB RAS). The irradiation was performed in a residual argon atmosphere at a pressure of 0.02 Pa with the following parameters: 18 keV; 40 J/cm2; 200 µs; 0.3 c-1; 20 pulses. The selected mode, as shown by the results of modeling the temperature field formed in the surface layer of silumin, results in the surface layer melting of the material up to 70 μm thickness. Investigations of the elemental and phase composition, the state of silumin defective substructure in the initial state, and after irradiation with an intense pulsed electron beam were performed using scanning electron microscopy (SEM-515 Philips) and transmission electron microscopy (JEM 2100F), X-ray diffraction (XRD 6000, imaging copper-filtered radiation of Cu-K 1, monochromator CM-3121). The samples microhardness was being determined with the PMT-3 device with an indentor load of 0.1 N. The wear-out parameter and friction coefficient were being identified on a TRIBOtechnic tribometer. The results of the studies performed revealed that the high-speed melting and subsequent high-speed crystallization were led to a nonporous surface layer forming of up to 100 μm thickness with the structure of cellular crystallization free of primary inclusions of silicon and intermetallides. The size of the cells of high-speed crystallization formed by a solid solution based on aluminum was 0.4-0.6 μm. The cells were separated by interlayers enriched with silicon, copper, nickel and iron atoms. The transverse size of the interlayers was up to 100 nm. It was revealed that the nonporous surface layer formation with a multiphase submicro- nanocrystal structure was accompanied by an increase in the silumin microhardness by 4.5 times, and wear resistance by 1.2 times compared to the cast state. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parkhaev E. S., Semenchikov N. V. Wings aerodynamic optimization technique for small-sized unmanned aerial vehicles. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 7-16. The article suggests combined technique for wings aerodynamic optimization of mini unmanned aerial vehicles (MUAV), which flight modes correspond to critical Reynolds numbers within the range order of 105–106. According to this technique, non-viscous flow-around, flow without separation and aerodynamic characteristics of the finite span wing are being computed in the beginning. The wing planform shape, wing aspect ratio and other geometrics are assumed known and specified. Computation is performed by reliable panel technique. Then the wing profiles shape optimization is performed with account for laminar-turbulent transition, and separation phenomena.
The following assumptions were assumed while wings optimization algorithm developing: the flow-around parameters computation employing 3D analysis model is non-viscous and non-separable. Viscous separated flow-around computing is performed in the contest of 2D-problem of viscous-invicid interaction. Integral aerodynamic characteristics over the wing span are being computed by the technique of lifting line theory using nonlinear section lift data. The suggested technique came from the supposition that aerodynamic characteristics of an isolated wing profile can be extrapolated on the wing. It associates with the fact that the MUAVs wings have, as a rule, a large aspect ratio (AR> 3), and hypothesis of flat sections is applicable for such kind of wings.
The article presents the results of numerical optimization on maximum quality criterion for rectangular wings planform, aspect ratios AR = 5 and AR = 10, at Re = 200 000, as well as arrow-type wing employing the suggested technique.
It was demonstrated that, the moment coefficient constraint allows increase the wing lift-drag ratio, reducing the share of resistance associated with laminar-turbulent transition occurrence and local flow separation formation. At the same time, while optimization in the absence of the moment coefficient constraint each successive quality improvement occurs due to the moment coefficient and wing middle surface curvature increase. The Cya(a) distribution herewith deviates from the initial one. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khmelnitskii Y. A., Salina M. S., Kataev Y. A. A spacecraft solar batteries panels strength calculation. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 17-24. The solar battery panels can be divisible by construction into the following types:
– Solar batteries with panels in the form of a frame with the stretched net-like fabric (net-like fabric panel);
– Solar batteries with panels in the form of a frame with orthogonally stretched strings (a string panel);
– Solar batteries with panels in the form of a frame with the stretched flexible film (a film panel);
– Solar batteries in the form of three-layer panels with a honeycomb core (a panel with a honeycomb core);
– Solar batteries with three-layer panels of integral construction (an integral panel).
The structures analysis of various panels reveals that at present all world firms employ generally three-layer panels with honeycomb core.
The structure of such panel consists of carbon fiber-reinforced plastic encasement and a metal honeycomb core.
Pursuing a goal of developing the rigid and light panel, recommendations on selection of carbon fiber-reinforced plastic, honeycomb core, adhesive film and dielectric film are issued based on experiments.
It allowed create lightweight rigid design structure of a solar panel. It was necessary herewith to perform strength, rigidness calculations and vibrations under effect while transportation and operation.
The stress-strain state of panels, forms and natural frequencies were being defined. Calculations were performed by a finite element method in MSC/Nastran.
CQAD4 sheathing element was selected for encasement and honeycomb cores modelling. The CQAD4 element accounts for all internal forcing factors and the encasement geometry, since it perceives membranous, shear, transversal and flexural loadings.
Calculations reveal that tension, occurring in the elements of the offered light-weight structure, have considerable safety margin, and high rigidity at which the maximal shifts do not exceed 0.05 mm, while oscillation frequencies change in within range of 16-91 Hz. The three-layer panel specific mass herewith is only 1.27 kg/m2. The structure opens possibilities for further improvement. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Smirnov A. V., Egoshin S. F. Energy balance analysis of prospective regional turbo-electric aircraft. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 25-33. The presented work deals with studying the possibility and practicality of high-temperature superconductors (HTSC) application while regional aircraft with hybrid electric power plant (the flying weight of up to 50 tons) developing.
The analysis was performed with mathematical model based on collating the power plant required and disposable power while a cruise flight. The basic energy and mass equations, characterizing hybrid power plants of various structures, including the structure with HTSC application, were derived.
It was revealed, that the turbo-electric aircraft is inferior to the aircraft with conventional power plant in the disposable power value. With application of conventional electrical materials, such as copper, this penalty is significant at any flying weight, and such hybrid aircraft developing is inexpedient. With HTSC technologies application this penalty is significantly lower, but it persists at any flying weight.
It can be explained by the presence of additional units in the power plant, which weight is much higher than the weight of the reducing gear, which they replace. The specific mass characteristics of the units based on conventional electric materials are significantly lower, than for HTSC units, which explains the difference in their application effectiveness. The efficiency change of power transfer herewith is insignificant.
At the same time, it was demonstrated in the framework of the model that the trend of the turbo-electric aircraft upgrading was application of installations and units (both gas turbine engines and electric motors) with the most advantageous specific energy-mass characteristics. With this, as it follows from the derived equations, the power plant should include minimum possible number of electric motors based on HTSC technologies.
It was confirmed in the framework of the constructed mathematical model that if the development of superconductor technologies allows develop HTSC-motors with specific characteristics at the level of 20 kW/kg, then the turbo-electric aircraft disposable power would attain the disposable power values of aircraft with classic power plant. It will ensure unconditional possibility for energy effective regional hybrid aircraft creation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kargaev M. V., Mironenko L. A. Bending stresses computation in a helicopter unmoored rotor blade blown about by the wind flow. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 34-43. Ensuring the main rotor blade strength remains as before one of the main problems, the designer faces while developing a helicopter. Heretofore, at the main rotor blade design in a part of static strength ensuring, the designers confined themselves to its computing under the impact of a force of its own weight. While a helicopter operation thereat, the damages of the main and tail rotor units occur after the storm wind impact.
For the main rotor blades, the following situations are possible: the blade spar bending with residual deformation occurrence down to its destruction; corrugation occurrence at the tail sections; the blade contact with ground or the helicopter tail beam. The above said phenomena prove to be possible due to the small inherent rigidity of the rotor blades, which makes them rather sensitive to the wind loading. The designers should take measures on the wind-flow impact protection ensuring while developing rotary wing aircraft.
According to the 29.675 b item of the AC 29-2C recommendation circular, which gives procedures for determining compliance with the requirements of the AP-29 airworthiness standards, when designing the carrier system, it is necessary to avoid overloading the stops and blades in conditions of wind gusts in the parking lot, or from the rotary wing aircraft's main rotor, taxiing nearby.
The article presents a method for computing flexural stresses in an unmoored blade of a helicopter, blown over by a wind flow. It consists in determining the positions of the elastic axis points of the idealized blade model.
These positions fully determine the shape of deformations and, hence, the magnitude of flexural stresses acting in the blade. The initial equation of the blade bending by a wind loading in a linear setting by the Galerkin method is reduced to an equation relative to an unknown deformation coefficient. This coefficient is determined under the condition of neglecting the additional aerodynamic loadings stipulated by the blade elastic deformations, and with their accounting for. The load increase factor was determined from comparing the obtained relations comparison, on which basis the solution allowing avoid the direct integration of the initial equation was obtained.
The equations are presented in a form convenient for numerical determination of the elastic axis points positions of the blade, slope angles and bending moments (stresses). Computation results for the rotor blades of the Mi-8 helicopter are presented. It was shown, that accounting for elasticity introduces significant changes in the bending moments (stresses) distribution along the angle of the blade azimuthal position, which determines the direction of its blow over. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lopatin A. A., Gabdullina R. A., Terentev A. A., Eremeeva C. F., Biktagirova A. R. Analysis and characteristics of prospective thermoelectric generators in aircraft electric power supply systems. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 44-54. The goal of the presented work consists in developing a technique for computing a part of the aircraft engine casing realized as a thermoelectric generator. The thermoelectric generator (TEG) application onboard an aircraft allows discard the mechanical electric current generator, operating on account of energy extraction from the aircraft engine rotor. At present, a great number of thermoelectric materials, prospective for practical application have been studied. One of prospective trends in this matter is application of housing elements as a basis for TEGs design. The aircraft power plant is undoubtedly the most thermally burdened component. The temperature field along the engine path herewith is characterized by a significant gradient.
Since the thermoelectric gadgets' computing is accompanied by certain difficulties associated with electric and thermal parameters dependencies, the authors developed the technique for computing a housing element, represented in the form of thermoelectric generator of a cylindrical shape. The article presents computation results, performed according to the developed technique, which allow determine and evaluate the value of power output, as well as TEG electric parameters and boundary temperatures of housing walls at the design stage.
The electrical power of the thermo-generator module depends on the flow rate, which cools one side of the housing: a small increase in its speed up to 40 m/s, the power output increases up to 1 kW. It can be seen that under similar conditions with flow rate growth from 50 m/s the power output increases only by 550 W. A similar situation is observed for the case when a TEG is made of of bismuth telluride. Characteristic presented in the article allows determine what engine operation mode would be the most optimal for the TEG effective implementation onboard an aircraft.
To study characteristics and parameters of thermoelectric generator the test bench was employed. The following parameters were measured while the experiments: the resultant current and voltage in thermoelectric modules connected in series (each module is a 64 thermocouples per module, connected in series cased in an insulating ceramic housing), hot and cold junctures temperatures, speed and temperature of the hot and cooling flows.
The paper presents numerical and graphical results of analytical and experimental studies, on which basis the inference can be drawn on the perspective of practical implementation of thermoelectric modules as aircraft engines components. The prospect of TEGs application in high-temperature aircraft and spacecraft power plants is determined by the necessity to obtain powerful enough electric power source onboard with modest weight and size characteristics and high reliability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Miodushevskii P. V., Legovich Y. S. Development of prospective multipurpose convertiplane. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 55-63. Domestic and foreign helicopter building development in the last century opened prospects for convertiplanes application as transportation means for carrying cargoes of considerable weight over the vast territory in conditions of deficiency of the advanced airfield net. Convertiplane is capable of performing vertical take-off and vertical landing. However, convertiplane can ensure significant fuel or electric energy saving while horizontal flight compared to the helicopter of the same weight. Aviation history knows two successful practically realized convertiplane projects. The first project was Canadair CL-84. The second project was the US V-22 Osprey military transport convertiplane. Aero-mechanical schemes of both Canadair CL-84 and V-22 have significant disadvantages. The presented work offers an original convertiplane aero-mechanical scheme, eliminating these disadvantages.
The article lays out the results of studying characteristics of the developed multi-purpose convertiplane, possessing conceptually new aero-mechanical scheme. Various options of the multi-purpose convertiplane, such as ten seats passenger plane, special plane for rescue missions and ambulance, light unmanned convertiplane with high flight duration are considered. Technical characteristics of convertiplane were determined based on the developed technique of preliminary design employing computations of aero-mechanics, aerodynamics, structural strength, weights and centring, as well as comparing the results with the well-known calculation methods.
The results of the studies revealed that among all realization options the offered multi-purpose convertiplane configuration allows achieve higher characteristics, than those of conventional aerial vehicles.The article demonstrates that the existing technical state-of-the-art level allows developing a light multi-purpose convertiplane.
Convertiplane gains its significant advantages through the new turbo-electric power plant, where the last achievements of developing light and powerful electric generators and motors with high power to weight ratio values is employed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Huang S. ., Kostin V. A., Laptevа E. Y. Application of the sensitivity analysis method for the solution of the inverse creep problem of a wingbox structure on the basis of super-element model. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 64-72. The research paper considers the problem of isochronic curves recovery of thin-walled design structures creep referred to deformations measured within the process of full-scale live experiment. It is known that as time passes creep deformations can appear in the construction. They are graphically usually represented as «deformation-time» curves measured by standardized sample testing. However, it has been found out that the deformation curves obtained during testing procedures of the construction differ fr om standard samples due to various reasons: power-based, technological, thermodynamical, etc. The article presents an approach to the corresponding curves construction, based on the processing of the results of the aircraft construction strength experiment.
Setting up the problem for general thin-walled constructions in mathematical terms, we obtain the necessity to optimize the objective functional in the form of the squared residual error of the corresponded theoretical and experimental deformations to the minimum. Working out the solution of the optimization problem is carried out iteratively using the sensitivity matrix, which is the derivative of the deformation function vector along the vector of elastic parameters variables. As the required parameters which control the stress-strained state (SSS) of the structure we choose the secant elastic modulus of the material. To solve a direct problem of the stress-strained state value determination the finite element method (FEM) in the form of a super-element model is used. This makes it possible to reduce the number of diverse required parameters at sufficient accuracy.
Due to the lack of data from the physical experiment, we obtain the numerical deformation values, using the FEM. This is done by solving a direct problem, wh ere measure of inaccuracy typical for strain and load application gauging is introduced. A mathematical calculation has been made for a four-stiffener wingbox operating under the mechanical and temperature load. Figures of the first and second stiffeners show the change of values of the theoretically obtained deformations in case of iterations in the direction of the corresponding experimental values. Isochronic creep curves have been constructed. The application of the sensitivity function has made it possible to purposefully organize the iteration process in the search for elastic parameters and to construct creep curves for the structural elements. The results of the research can be useful for further development of methods of identifying and improving of thin-walled structures according to the testing data, in case of creeping process as well. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Filinov E. P., Avdeev S. V., Krasil'nikov S. A. Correlation-regressive model for small-sized aircraft gas turbine engines mass computation. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 73-81. The article suggests several new correlation-regressive models for the aircraft small-sized gas-turbine engines mass computation at the stage of their conceptual design.
A database of the main data and thermodynamical parameters for mass computation of dual-flow turbojet engines was formed. The database includes 92 small-sized turbojets with the thrust less than 50 kN. Equations allowing compute the engine mass at the initial stage of design were derived by correlation-regressive method based on the accumulated statistics.
Model No. 1 uses the total air flow through the engine as an input parameter. The approximating function coefficients were determined based on 88 turbofan engines. The relative standard deviation value for this model was 25.5%.
Model No. 2 uses engine thrust as an input parameter. The approximating function coefficients were determined based on 92 turbofan engines. The the relative root-mean-square deviation value for this model was 18.6%.
The mass model No. 3 uses three input parameters: engine thrust, overall pressure ratio, by-pass ratio. This model involved 77 turbofan engines. The relative root-mean-square deviation value of this model was 13.4%.
The fourth model uses the total air flow, overall pressure ratio, gas temperature in front of the turbine, bypass ratio for calculating the mass.
Statistical coefficients for this model were determined based on 57 turbofan engines. The relative root-mean-square deviation value for this model was 10.1%.
The Kuzmichev mass model depends on five parameters of the gas turbine engine: Mдв = f (m,πкΣ,Gв,T*г, πв) . The total number of engines used in the statistics was 52. The relative root-mean-square deviation value of this model was 13.5%.
Based on the results obtained, we can draw the following conclusions: at the stage of the gas turbine engine conceptual design, the most preferrable models are model No. 4 and Kuzmichev's model. Models No. 1, No. 2 and No. 3, are most preferable for preliminary estimation of the mass of the propulsion system while an aircraft design. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fokin D. B., Selivanov O. D., Ezrokhi Y. A. The studies on optimal shape forming of a turbo-ramjet engine as a part of a high-speed aircraft power plant. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 82-96. Recently, the great attention is payed in many countries to the studies aimed at flight cruising speed increase of aircraft of various purposes. The projects aimed at considering the issues creating both passenger (Aerion AS2, QueSST, Sky-lon) and military (SR-72) high-speed aircraft are in full swing abroad.
The similar studies on building-up the flight speed of military planes are carried out in Russia too. Thereupon, the possibility of developing prospective Russian fighter-interceptor based on MiG-31 aircraft, which speed should substantially increased, presents undoubted interest. The same applies to an attack high-speed aircraft of the type of the Soviet T-4 scout bomber, or the US XB-70 “Valkyrie” strategic bomber with maximum flight speed, corresponding Mach number no less than M = 3.
The article presents the results of the study on the power plant optimal shape based on the turbo-ramjet engine with tandem configuration of the high-speed aircraft contours with cruising speed of Mcr = 4.
To solve the stated problem, the software complex consisting of mathematical models of the combined engine, including gas-turbine and direct-flow circuits, supersonic air intake and a full-range jet nozzle, as well as the technique for the aircraft performance characteristic computing. The developed program complex allowed evaluate the efficiency of such combined power plant application as a part of an aircraft with increased cruise speed.
The presented results demonstrated with high obviousness that the effort aimed at the power plant optimal shape formation is most expedient to perform in accordance to the procedure of optimization studies performing, which includes the task setting, the initial data preparation, parametric studies, post-optimization analysis and issuing recommendations.
Parametric optimization with seven parameters and three criteria with goal functions of subsonic and supersonic flight ranges at the optimal altitude, as well as required length of runway for the aborted-continued takeoff, was performed employing the above said approach. The optimization results revealed that the possibility of improving an high-speed aircraft performance relative to the conditionally preliminary basic variant.
Three aircraft options with the highest attractiveness level were selected out of the obtained twenty Pareto-optimal options by the “fuzzy sets” tool. Further final selection of the most expedient one out of these options always up to the development engineer and associated with taking a number of trade-off decisions.
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Orlov M. Y., Anisimov V. M., Kolomzarov O. V. Design refinement of combustion chamber of gas turbine engine with toroid recirculation zone. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 97-106. The design of a serial auxiliary power unit was employed as a prototype while developing a new engine. The schematic solution of inlet unit and centrifugal compressor was preserved in the new design, while the engine turbine underwent changes right from the start, since it became radial instead of axial. It required the changes of the combustion chamber design. After studying a number of possible schemes, a decision was made to choose the straight-flow combustion chamber of a ring-type of, which had substantial reserves for minimization on size with relative simplicity of its technological design. The specific feature of this particular combustion chamber is its diagonal positioning relative to the engine axis. A number of problems associated with the lack of experimental and calculation data arise while organizing a working process in the combustion chamber of this type.
The goal of the study is design refinement of the considered combustion chamber structure to optimize the workflow of the annular combustion chamber with the offset zone of a toroid type.
At the first stage, the design refinement of the flame tube structure was performed to organize a vortex structure in the primary zone by changing diameters and a number of clamping apertures and addition of a «springboard» of the internal rim of the flame tube. At the second stage the design refinement of the seat of flame in the primary combustion zone was performed. The atomizer was substituted by the spray injector, and vane swirlers were added to the duct between the deflector and the flame tube wall. The third stage was devoted to the necessary temperature field forming at the combustion chamber outlet. For this purpose the works shaping-up the necessary jets penetration depth, the number and location of shift apertures were performed.
The outcome of the activities consists in obtaining acceptable combustion chamber design of the engine being developed, in which the authors succeeded achieving the flame stabilization in the primary combustion zone, temperature field distribution inside the chamber, excluding its burn-through, and temperature filed irregularity reduction at the outlet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Finogenov S. L., Kolomentsev A. I. Solar thermal rocket engine with beryllium-oxide phase-transition latent heat energy storage and hydrogen afterburning. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 107-115. The article considers solar thermal propulsion (STP) with thermal energy storage (TES) containing high-temperature phase-transition material – beryllium oxide possessing high latent heat of phase transition “fusion-crystallization”. High melting temperature allows obtain the engine specific impulse at a level of 9000 m/s.
Joint optimization of the basic relevant parameters, such as masses ratio of solar mirror concentrator and TES in combination with mirror accuracy parameter was performed. It was demonstrated that that the ratio of TES energy capacity to solar radiation receiver thermal power, or ratio TES energy capacity to solar concentrator area in conjunction with optimal selection of accuracy parameter of the mirror can be accepted as an optimizing parameter. Maximum mass of a spacecraft being placed into geostationary orbit with time limitation of inter-orbital transfer from 30 to 90 days was selected as optimization criterion. Optimization was performed out by Gauss-Seidel method.
The optimization results revealed that optimal ratio of TES energy capacity and light detector power was 22-24 MJ/kW, which corresponds to the optimal ratio TES energy capacity to the concentrator area of 6-7 MJ/m2 at rational mirror accuracy parameter of 0.25 degrees. The STP characteristics with TES are presented and analyzed. The article shows that for relatively small flight time of 3040 days optimal values of excess oxidant ratio corresponding to payload mass maximum. The higher value of excess oxidant ratio corresponds herewith to the lower value of the flight time.
Dependences of the TES energy capacity and the concentrator diameter from excess oxidant ratio for a wide interval of flight duration are presented. Expedient areas of heated hydrogen afterburning application for various inter orbital flight duration were determined. The article shows that afterburning is expedient for the time of putting to geostationary orbit of 30 to 45 days. The corresponding excess oxidant ratio changes herewith from 0.3 to 0.1. For the flight above 50 days, the monopropellant hydrogen STP is expedient. Compared to alternative inter-orbit transportation means, employing the combination of small and large thrust engines combination, the gain is about 450 kg under the one and the same inter-orbital transportation time of 60 days. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Remchukov S. S., Danilov M. A., Chistov K. A. Computer aided design and computing of a plate-type heat exchanger for small-size gas turbine engine. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 116-123. The article presents computational complex allowing perform computer aided design and calculation of a compact heat exchanger for a small-size gas turbine engine.
The coomputational complex includes a number of blocks based on open commercial programs. The blocks are united by the common software algorithm, developed at Central Institute of Aviation Motors (CIAM).
The input data is changed at each iteration to obtain the required parameters, namely, the regeneration degree and hydraulic resistance.
Computer aided design and calculation include the steps of the initial data entering into the parametric model, checking compliance with the restrictions, automatic model building, meshed models preparation, working medium flowing calculation and computational results output. The initial data is set with account for limitations, such as overall size restrictions and material outlet depth. The possibility of obtaining better thermohydraulic characteristics depending on the model geometry should be accounted for as well.
Automatic building of models is performed according to the set parameters.
At the next stage, the built models are loaded to the ICEM CFD program, and meshes building is performed.
The obtained grid models are used for calculation in Ansys CFX software. Full pressures and temperatures of air and gas at the inlet, as well as the flow rate of gas and air at the outlet are set as boundary conditions. The employed turbulence model is Shear Stress Transport model.
After calculation termination, the resulting file, containing all significant exchanger computational parameters, is formed in the form of a table.
In case of the obtained parameters discrepancy with the claimed requirements, the parameters correction is performed with subsequent repetition of the considered algorithm.
Automation of the design and computing algorithm allows employing it together with CAD complexes for multi-criteria optimization.
The developed computing complex allows obtaining the optimal heat exchanger configuration for a specific task within the specified limits. The calculating complex was being employed in CIAM for the heat exchanger envelope updating, which led to the regeneration degree increase from 62% to 76%, when total hydraulic losses decreased to 1,27% with requirements and restrictions compliance. The genetic algorithm was used as an optimization method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gulienko A. I., Schurovskiy Y. M. Experimental study of gte lubricating system oil-air mixture properties. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 124-133. Lubricating system of the gas turbine engine rotor supports in many ways determines its operation reliability. The experience in developing aircraft GTEs lubricating systems accumulated by many manufacturers is associated with predominant employing of empirical and experimental techniques, and is not practically covered in literature. As a rule, the lubrication systems characteristics are being determined while operating with pure oil, and their recalculation onto the two-phase mixture may lead to overpower of the driving pumps motors and, as consequence, to their weight increase.
The article presents the analysis of the properties of two-phase mixtures pumped through the unit of the aircraft GTE lubrication system based on experimental data. This data was obtained at CIAM with the test bench for semi-natural simulation of lubrication system with oil chamber imitation, and installation for fine-dispersed oil-air mixture forming, where the mixture is formed by the air entrainment effect.
Using the results of oil-air mixture flow visualization, the article shows that in the area of the GTE lubrication systems operating modes the mixture may be considered as one-component homogenous media, possessing the properties of elastic continuum with homogenous sound velocity.
While air entering the exhausting duct the two-component flow of oil-air mixture and air-oil bubbles, clogging the pipe cross section and move relative to the oil-air mixture at low speed is formed.
Characteristics of a discharge gear pump, pumping the oil-air mixture, are affected not only by air and oil properties, but also by the structure formed by the pump throughput capacity.
It has been shown that in GTE lubrication systems a mode of emptying the exhaust gear pump inlet branch may occur with the possible realization of the stratified flow structure, as well as a dynamic locking mode in which a pulsating flow is formed with density waves forming and a polyharmonic fluctuations excitation in the system. Based on the experimental data, the air-oil mixture flow modes map was compiled.
The paper presents the relationships by which give possibility to calculate the thermo-physical properties of the two-phase mixture pumped in the tracts of the GTE lubrication systems. This approach showed good agreement of calculations with experiments in the lubrication system static and transient operation modes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenova A. S., Gogaev G. P. Evaluation of destructive rotation frequency of turbo-machine disks applying deformation criterion with LS-DYNA software. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 134-142. Turbine disk is the main part of the aircraft engine, since its failure may lead to either emergency or catastrophic situation. According to NTD the GTE load-bearing capacity is being evaluated by the destructive rotation frequency margin, applying the limit equilibrium theory, at destruction along meridian section fr om tangential stress, and at destruction along some cylindrical partially meridian section fr om tangential stress.
Factors affecting the disk load-bearing capacity are the meridian section shape, scheme of destruction (along meridian, cylindrical or mixed sections), the presence of stress concentrators, and the material properties. Allowance for these factors effect on the disk load-bearing capacity while applying the lim it equilibrium theory is not practical.
Destruction of most metals is the result of damages accumulation. Two main mechanism of damages such as voluminous damage (pores growth and merge) and shear damage (cracks growth and merge) are discerned. A model of damages accumulation based on shear damage, i.e. destruction criterion on maximum accumulated plastic deformation, can be employed for numerical determination of the destructive rotation frequency of the turbo-machine disks from nickel alloys.
The plastic flow theory can be employed to determine the disk lim it rotation frequency. A modified version of the classical flow theory with isotropic hardening makes allows implement an arbitrary stress-strain dependence given in the form of strain diagrams.
Several series of calculated overspeed test were performed. The effect of the following factors on the calculated destructive frequency was being studied:
– loading speed;
– the finite elements mesh size.
The computational studies results revealed that the finite element size and mesh computing time did not practically affect the convergence of computation and experiment.
The computational studies results revealed that the finite element size and mesh computing time did not practically affect the convergence of computation and experiment. However, the smaller the grid, the more accurately the cracks development on the disk can be traced.
The obtained computation results were validated based on the results of the overspeed test performed with the low-pressure turbine disk of AL41F-1C engine at the Central Institute of Aviation Motors (CIAM) stand. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolychev A. V., Kernozhitsky V. A., Levikhin A. A. Cooling system of gas turbine engine turbine blades made of heat-resisting alloys and conductive ceramics. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 143-150. The article deals with thermionic cooling system (TCS) of turbine blades (TB) and other hot elements (HE) of aircraft gas turbine engines (GTD), which consists in coating them with a layer (thermionic- protecting layer (TPL)) from heat-proof and heat-resisting material, but with a low electronic work function (EWF). When the TBs and HEs heating, electrons start leaving their surface, taking with them 2-10 MW/m2 of thermal energy in exponential-like temperature dependence. It will allow increase significantly the GTE efficiency due to the temperature increase of the working gas prior to the turbine and extra thermionic transformation, as well as increase the GTE reliability and lifespan.
The thermionic cooling technique under development can be employed in aircraft building while creating power gas turbine installations-converters for the spacecraft of increased power capacity and prolonged active lifespan. It can be implemented also while developing commercial systems of putting a payload and tourists into orbit, including a spacecraft based on the reusable first stage of an aircraft type with GTE, or transport aircraft with thermionic GTE. Besides, the technology under development will be called-up for the fuel-and-power sector and shipbuilding while power plants developing, and in oil and gas sector for gas pumping units developing etc.
The TCS realization will allow increase the temperature of the working gas prior to the turbine without increasing the quantity of the air tapped off the compressor, or increase the resource of the most thermally stressed elements of the gas turbine parts, the efficiency increase, thermal stresses reduction in blades due to the thermionic sensitivity to the temperature. It will ensure continuous diagnostics of the turbine state and other high-temperature elements in real-time mode based on electrical engineering parameters, depending on the number of thermo-emission electrons perceived by the anode, and modernize gas turbine installations and GTEs produced in Russia with their resource enhancing due to the extra cooling and without their serious reconstruction. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Donskov A. V., Mishurova N. V., Solov'ev S. V. Automated system for space vehicle status monitoring. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 151-160. The article considers the issue of a space vehicles status monitoring automated systems developing.
The goal of the work consists in analysis and application of the tools for flight control systems of conventional spacecraft improving.
The technique of a manned spacecraft current state status monitoring with account for affecting factors (an aircraft orbital movement parameters, structural specifics of an aircraft and ground-based control loop), as well as a throughput of radio communication circuit for telemetric information transmitting, sensor equipment capabilities, onboard measuring instrumentation and computing means were studied.
The conclusion was drawn, that the tasks of controlling processes automation while spacecraft flight control are not exhaustive.
Depending on the designation of an individual spacecraft or spacecraft orbital group not only the tasks and their aggregate set can change, but specific and independent assignments may arise as well.
With account for the current flight control practice in manned astronautics the approach at large to a space vehicles' on-board equipment status monitoring automated systems developing was formed. Automation of problems solving on telemetric information displaying and analysing coupled with information support of a specialist of the group of analysis allows increase the quality level of the managing group functioning. It is achieved through detecting an abnormal situation, potentially translating into emergencies, as well as operational provision of flight control operators with information over a wide range of the problems being solved.
The significance of the spacecraft status monitoring automated systems developing is being proved by the fact that it allows minimize the human factor in the process of a spacecraft control, increase information accessibility and ease-off the burden of analysis group specialist while performing routine operations.
The considered approach to the spacecraft status monitoring automated systems developing can be applied to both the process of of existing manned space vehicles flight control process improvement, and prospective manned spacecraft under development. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilenko N. V., Kirenchev A. G. Work process of the earth environments vortex formation. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 161-170. The present-day science state-of-the-art allowed ensuring qualitative transfer to many branches of not only scientific but to technologic and other types of human activities. New knowledge aroused at the junction of the well-known scientific and technological trends. Though in certain trends of modern science development some so-called “blind-spots” still exist. The theory of vortex formation is an example of such modern science state-of-the-art. Currently the specialists of this scientific trend cannot establish the physical entity of atmospheric gas dynamic specifics of the vortices under the aircraft air intakes, well as the gist of their work process. The closer analogue of such vortices are the atmospheric whirlwinds, which working processes are associated with the Earth daily rotation. However, the capabilities of modern science do not allow establish the work process of the above said problem gas dynamic phenomena. The scientists in the USA and many other countries declare openly that the do not understand tornado – a small-sized vortex of a cyclonic type. In such circumstances, the scientists are compelled to give definitions to whirlwinds, tornadoes and cyclones by the facts of their physical manifestations in the field of visual perception. Such definitions do not contain the boundary conditions, work process elements, and limit their experimental modeling possibilities. The scientists face a great problem of exploring the work process of the Earth environments vortex forming. One of the main tasks of the Earth environments vortex forming research and its product is establishing the vortex characteristics, their corollary and application areas.
The article discloses the work process of the Earth environments vortex formation. It gives the definition of vortex formation, and specifies the product of vortex formation, including vortex field, tornadoes and air intakes vortices. The work process of vortex formation was established. The article presents the Earth vortex filed characteristics and their corollary.
The Coriolis force role in the process of vortex formation of natural and man-made vortexes was revealed. The results of experimental modeling of vortex formation under the air intake with account for the Coriolis force action are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Razoumny Y. N., Samusenko O. E., Nguyen N. Q. Optimal options analysis of two-tier satellite systems for near-earth space spherical layer continuous coverage. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 171-181. Nowadays, there is a wide nomenclature of practically new significant tasks of monitoring vast near-Earth space areas by space systems, associated with the space debris problems, spacecraft technical maintenance in orbit etc. All tasks of such kind in an abstract formulation can be interpreted in the form of mathematical problem on optimization of the satellite constellations orbital construction for continuous coverage of specified spherical layers of near-Earth space. However, still there is no theoretical apparatus for effectively solving this problem.
The article formulates for the first time the optimization problems of the two-tier satellite constellations orbital construction for near-Earth spherical layer continuous coverage by the criterion of the characteristic velocity minimum total costs on the system creation. Each tier of such a system is formed in circular orbits with the same altitude and inclination values for all satellites. The satellites of each tier are oriented herewith in such a way that observation cone, formed by the onboard equipment of the satellites in the upper tier are directed downward towards the Earth, while in the upper tier – towards the opposite side.
Decomposition of this problem and its reduction to the traditional problem of selection in the delta-systems class of one-tier orbital constellations and their optimization by the total characteristic velocity minimum was performed in this work. The authors suggest methodological approach to this problem solving; discuss the obtained numerical results and the suggestion on application of the obtained optimal options of the two-tier satellite systems for solving various practical tasks. The two-tier orbital structure in many cases has no advantage over the traditional, single-tiered option. However, under certain conditions the two-tier orbital construction appears after all more preferential. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalev A. A., Tischenko L. A., Shakhovtsev M. M., Gorbatovskaya T. A., Vlasov E. Y. The study of silicon substrates pre-treatment technological parameters effect on their surfaces contact angle. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 182-189. The presented article deals with the study of technological parameters (temperature and processing time in hexamethyldisilazane (or HMDS) vapours and dehidration) effect on contact angle of silicon substrates pre-processing, including oxidized ones, to evaluate their hydrophobicity. Contact angle measurements were being performed by method suggested by Bickerman. Those angles values were being obtained indirectly due to the known volume and diameter of a water drop. For non-oxidized silicon substrates technological parameters effect on contact angle consists in the following: the 1.5 degrees increase with 30 seconds increase in time of processig by HMDS vapours, 1.2 degrees increase with 120 seconds increase of dehydration time, 0.6 degrees decrease with 45 degrees increase of processing temperature. For oxidized silicon substrates technological parameters effect on contact angle consists in the following: the 2 degrees increase with 30 seconds increase of processing by HMDS vapours, 0,2 degrees increase with 120 seconds increase of dehydration time, 1 degree decrease with 45 degrees increase of processing temperature. Experimental data analysis was performed by Yates analysis, i.e. full fraction analysis. Based on the obtained results the inference was drawn that increasing time of substrates processing in HMDS takes the strongest effect on their contact angle change. Besides, on substrates temperature increase the contact angle decreases irrespectively to the oxide film presence or absence on their surface. The latter, probably, is associated with the fact that hexamethyldisilazane evaporates from the substrate surface, since their maximum heating temperature was close to the HMDS boiling temperature while this study. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grachev N. N. Quality evaluation of aircraft electronic instrumentation assembling based on registration and analysis of mechanical joints electromagnetic emission. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 190-202. The scientific significance of the results outlined in the work consists in studying mechanisms of contact radio interference originating, occurring due to the magnetic field effect of radio transmitters, located onboard an aircraft, on current-conducting mechanical contacts of the structures with non-linear variable resistance, as well as electromagnetic interference generation. The scientific results obtained from the studies demonstrated mechanisms of forming the current, induced by EMF, passing through the aircraft structural elements, which leads to formation of a mechanism of secondary electromagnetic field radiation, interacting with the primary irradiating magnetic field of the radio transmitter. There is a possibility to control the structural elements assembly quality by registering and analyzing the spectral composition of the electromagnetic radiation of the mechanically connected structural elements. Performing complex diagnostics, based on measuring the spectral content of the whole product, and placing antennae around the product under study allows performing reliable estimations of the assembly quality of both separate mechanic components and the entire structure.
The studies performed in this work can be applied to the development and study of a contactless express-method for assessing the structures assembly and erection quality. This method is based on the registration and analysis of artificially generated contact interference under the impact of mechanical vibrations and a high-frequency harmonic electrical signal on the aircraft structures' elements, forming phase-amplitude-modulated oscillation circuits, which can be recorded by either spectrum analyzer or a FAM receiver, or AM oscillations. With this, the levels of their spectral components are measured at a change of mechanical impacts frequency in the range determined by the operating conditions. The measured level of the spectral components of the emitted amplitude-modulated oscillations is compared with the level of the spectral components of the signal emitted by the reference block with given mechanical parameters and normalized level of contact interference.
The main result of these studies allows fruitfully employ the contact interference formation, considered as undesirable phenomenon in the field of electromagnetic compatibility, for estimating the mechanical qualities of the structures (their assembly quality) of various aircraft equipment and units, including assembly and erection quality (especially associated with fixture elements tightening force). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balkovoy N. N. Analysis of application specifics of a reaction wheel with intrinsic disturbing moments compensation. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 203-211. Inertial electromechanical actuators in the form of reaction wheels (RW) found widespread occurrence as actuators of spacecraft attitude control system. The RWs task consists in forming a dynamic controlling moment proportionally to a control signal. This task is reduced to the RW acceleration control.
The article suggests the RW classification, describes advantages and disadvantages peculiar to each of the types. Amid all varieties of the units, reactions wheels with intrinsic disturbing moments' compensation (RWMC) are outlined as one of the most prospective types. The presented work is devoted to the study of these units application possibilities and comparing them with classical ones, where control is performed only by the electromagnetic moment.
To study dynamic and accuracy characteristics of a spacecraft equipped with the RWMC under study, its mathematical model was developed. Analysis of the RWMC dynamic moment development transient was performed. It revealed that transfer functions of compensating and basic (electromagnetic moment control) loops may be represented with high accuracy by the aperiodic link. The time constants of these links were also obtained while the RWMC experimental testing.
The model of the controlled rotational motion accounts for the RWMC static and dynamic imbalances values, as well as the number of RWMC nonlinearities, such as saturation, associated with attaining the limiting angular speed by the rotor and the dead zone while the rotor passes the zero angular speed (for a model without disturbances compensation) etc. Modeling of the spacecraft control system operation in stabilization mode in conditions of ideal measuring of angular position and angular speed was performed to study the effect of the unit specifics on the control system operation.
The spacecraft attitude control system with RWCM was compared to classical RW. In both cases, the control system loop was closed by the PID-regulator, since external disturbances, affecting the stabilization static error value, impact the spacecraft together with disturbing moments.
The simulation results showed that RWCMs has higher accuracy and dynamic characteristics compared to the classical RW. This type of units appears more preferable for developing precise spacecraft attitude control systems, since it allows reduce the “dead zone” of control, as well as oscillation in stabilization transient, especially in the area of near-zero angular rotation speeds of the RW rotor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tereshkin V. M. Determining resultant current harmonic composition of an electric motor symmetric four-phase winding. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 212-219. Modern power electronics and microprocessor technology state-of-the-art allows develop DC-AC converter with any number of phases in a wide power range.
Realization of a multiphase motor (m > 3) based on the magnetic system of a 3-phase motor is also practically a feasible task with certain modernization of the winding scheme.
As an illustration the article presents a schematic diagram of the four-phase winding, its vector representation, as well as four-phase converter control algorithm while vector pulse-width modulation realization.
The electric drive based on a multiphase motor may display certain advantages in compared to the traditional electric drive based on a three-phase motor and find application wherein the higher requirements are placed on vibrations. The cause of vibrations of electromagnetic origin may be the high-order harmonics of the resulting current, which creates an m.m.f. in the air gap.
Preliminary studies revealed that symmetrical 4-phase winding had the worst figures of the spectral composition of m.m.f., compared to the 5- and 7-phase windings. However, the traction electric drive of the “Granit” electric locomotive was just realized based on the 4-phase asynchronous motor. That is the electric drive based on multiphase motor is already an alternative to the electric drive based on the three-phase motor. It imposes the necessity for comprehensive comparative analysis of multiphase windings and control algorithms for converters to which multi-phase windings are being connected.
The article considers an approach based on classical vector method. With its application harmonic analysis of a resultant current of the symmetrical 4-phase winding. The analysis revealed the phase currents' 1, 5, and 9 harmonics formed the resulting currents of positive-sequence, and the phase currents' 3, 7 and 11 harmonics formed the resulting currents of the negative sequence. Accounting for the fact, that the 1, 3 and 5 harmonics are commensurable in magnitude, significant electromagnetic ripples are theoretically possible within the first harmonic period.
The approach based on the classical vector method considered in the paper can be used to analyze the harmonic composition of the resulting current of multiphase windings with any number of phases. This makes the approach universal for the comparative analysis of multiphase windings on the harmonic composition of the resulting current. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Antipov V. V., Nochovnaya N. A., Kochetkov A. S., Panin P. V., Dzunovich D. A. Effect of casting parameters on shaped castings quality of a new high-temperature TiAl based alloy. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 220-228. The results of original research on cast structure and properties of a new high-temperature intermetallic gamma alloy Ti-45.5Al-2V-1Nb-1.5Zr(Cr)-Gd-B developed in VIAM [patent RU 2606368] have been discussed. A solidification temperature interval has been determined for the new alloy: solidus temperature 1471°C, liquidus temperature of 1528°C. The pouring gate system has been designed with the help of ProCast software taking into account centrifugal casting technique which provides both full mould filling with molten metal and absence of metallurgical defects in low pressure turbine blade castings. The research was focused on the effect of temperature and duration parameters of centrifugal casting on macro- and microstructures of shaped castings obtained in induction skull ALD Leicomelt 5 furnace. The X-ray spectral microanalysis has revealed that the samples matrix consists of alternating γ -TiAl and α2-Ti3Al lamellae; there are areas with lower aluminum content and higher content of vanadium and zirconium/chromium; also excess phases enriched with gadolinium and oxygen have been found (complex gadolinium oxides). Microstructure analysis after hot isostatic pressing has shown that plate-like morphology of structure doesn't change: alternating lamellae of γ and α2 phases are gathered into colonies within prior β(α) grains with small amounts of β phase along grain boundaries (the plates possess similar geometrical orientation within each lamellae colony). It has been shown that structure homogeneity of castings strongly depends on pre-heating temperature of casting moulds. As the experiment has revealed the optimal pre-heating temperature of casting moulds for the new alloy falls in the interval 750850°C. The research results have given the opportunity to develop casting and heat treatment processes which allowed to obtain defect-free shaped castings of turbine blades for aviation jet engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lapaev A. V., Ryashin N. S., Fomin V. M., Shikalov V. S. Properties of aluminum coatings of cold gas-dynamic spraying at corrosion damage zones of 1163RDTV alloy products. Aerospace MAI Journal, 2018, vol. 25, no 3, pp. 229-239. Cold gas-dynamic spraying is a method for coating process, creation of 3D objects and new materials from powder metals, alloys, composites and powder mixtures. The method was developed based on cognominal physical phenomenon, discovered at the Institute of Theoretical and Applied Mechanics named after S.A. Khristianovich of Siberian branch of the Russian academy of sciences in the early 1980s. Nozzle assembly and a heater are fixed as a part of the cold gas-dynamic spraying test bench based on the industrial robot KR 16-2 in dust-noise proof chamber. While spraying the powder particles are accelerated by the gas flow to the velocities of 400-1200 m/s and form the coating without melting. In a number of works of domestic and foreign researchers the possibility of metallic objects recovery by this method is demonstrated, whereby the study of coatings and materials obtained by this method presents an undoubted scientific and practical interest.
The presented article studies the properties of aluminum coatings formed by the cold gas-dynamic spraying method at corrosion damage zones of the substrates from 1163RDTV structural alloy.
At the first stage of work corrosion damages in the form of surface corrosion of the plates from the 1163RDT alloy were simulated. Then they were recovered by the cold gas-dynamic spraying coatings from ASD-1 aluminum powder. The average measured size of the ASD-1 powder particles was 27 mcm.
Experimental dependencies of porosity and micro-hardness of these coatings and oxygen content in them from deceleration temperature while spraying were obtained. These dependencies allowed sel ect the better coating process mode for performance characteristics recovery of structural elements with corrosion damage.
During the experiments of the second stage the samples recovered by the cold gas-dynamic spraying coatings from the 1163RDTV alloy were tested on tensile strength while static loading. Experimental deformation and fatigue endurance curves were obtained. Due to the low porosity and micro-hardness of the cold gas-dynamic spraying coatings, applied at T0 = 200°C, the samples with corrosion zones recovered by these coatings were selected for static and fatigue stretching tests. The obtained experimental results analysis revealed that with the considered coating process mode the full static hardness characteristics recovery did not occur. Nonetheless, an A1 recovery by the cold gas-dynamic spraying coating from 1163RDTV alloy increases the sample static hardness characteristics in the elastic region of the deformation curve. The fatigue tests revealed the effect of the stress concentrator on fatigue strength, which should be accounted while cold gas-dynamic spraying application for recovering corroded structural elements.
At the final stage of the work, a coating fr om ASD-1 was formed on the TU-154 stringer fragment (an alloy of B95 series). It demonstrates the ability of applying these coatings on the fuselage frame elements. The results of the presented work demonstrate the high potential of the cold gas-dynamic spraying method in solving the problems of aircraft construction elements recovery and repair. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pashko A. D., Belichuk A. A. Development of anti guided missiles active protection system for aircraft and assessment of its application prospects. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 25-36. At present, designers of almost all foreign countries (USA, UK, France, Germany, Israel, Japan, China and South Africa) decide upon thermal imaging tracking coordinator, employing matrix photo-detecting unit while the type of homing head selection for hew types on missiles. Its modern element base is intrinsically the basis of the fifth generation infrared homing heads. The main advantages of guided missiles of “air-to-air” class equipped with homing head containing matrix photo-detecting unit consist in the presence of significant field of vision, ensuring target patter recognition and its identification, capability of automatic aiming employing and high jamming immunity. All this requires aircraft protection means modernization.
Modern aircraft are being equipped with on-board defense systems, designed to protect an aircraft of various classes and purposes from hitting by aircraft rockets, antiaircraft rocket systems through detecting hazard occurrence and counteracting the attacking means. Onboard defense system “President-S”, “Talisman”, electronic countermeasures equipment of Su-30MKI and aircraft protection system “MANTA” are most up-to-date systems.
The results of performed analysis of modern aviation guided missiles and means of protection from high-accuracy weapons allow conclude that the existing onboard defense systems do not ensure enough level of protection. Namely, they ensure only a passive protection by creating interference action on missiles homing heads, which is inefficient with account for digital signal processing and jamming protection of the guided missiles. Modern heat flares are effective only for protection from the missiles' with single-element photo-detecting unit. Due to target image detection capabilities of modern homing heads with matrix photo-detecting units, the heat flares application is inappropriate. From all the above said, a topical problem of upgrading the onboard defense systems by developing new ways of an aircraft protection from guided missiles follows.
Improving the aircraft protection is possible by active impact on guided missile by protective ammunition included into active protection system, leading to its hitting, self-destruction or mishit.
The goal of the study is enhancing the aircraft protection from guided missiles of “air-to-air” type.
Thus, the developed active protection system is capable of ensuring in automatic mode all aspect detection and tracking of a guided missile, its destruction at a safe distance from the aircraft, in close interaction with the other aircraft systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sinitsin A. P., Goza D. A., Rumyantsev А. V. Thermal calculations of liquid low thruster on pollution-safe fuel. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 109-116. The article presents the results of development and application of the thermal model of a stationary liquid thruster on alternative mono-fuel. It allows calculate the thermal field, and determine internal and external conductive and radiation thermal fluxes, temperature variation gradients speeds in stationary and dynamic modes operating modes of the engine, and calculate heat emission in combustion chamber with subsequent recommendations on upgrading the engine thermal scheme and its reliability.
The purpose of the above said thermal calculation consisted in determining the thermal state parameters and characteristics of the low thrust rocket engine on alternative fuel. The thermal calculations using mathematical model developed and presented in this document solved the following problems: developing the engine thermal model, its verification by the thermal test results, calculation substantiation of the solutions,directed to temperature reduction of propellant delivery valve and capillary delivery tube.
The three-dimensional engine thermal model was built with SolidWorks Flow Simulation 2014, which employs the finite volume method ( a numerical method for integrating the systems of partial differential equations. In heat calculations, the boundary conditions were set identical to the conditions for thermal vacuum tests, which imitated the outer space in full-scale operating conditions.
The experimental data of the engine thermo-vacuum tests, obtained with the development design office Fakel test-bench, were used for the calculation thermal model verification. Verification of the thermalmodel consisted in heaters power selection from the condition of compliance of temperatures in the controlled points and measured ones.
Recommendations on thermal scheme optimization and constructional materials selection were developed according to the thermal calculation results.
Recommendations were also given on optimal structure selection of low-thrust liquid engine on alternative fuel for valve temperature reduction and power consumption reduction while thermocatalytic pack heating-up to +400 °C.
Several design options were considered, and recommendations were given on heat sink application and its impact on the thermal condition of the product, and the effect of the rack material on the thermal condition of the product. According to the results of thermal calculation of the engine structure in functioning mode recommendations are given on substitution of the engine structural elements (heater) and mounting blocks materials not answering the thermal criteria (working values the engine structural units temperature should not exceed qualification value of the temperature).
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Malenkov A. A. Design solutions selection while developing a system of unmanned flying vehicles in conditions of multi-target uncertainty. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 7-15. The article is devoted to the design solutions selection while developing a system of unmanned aerial vehicles in conditions of uncertainty. The presented article such system is assumed as a party of cruise missiles (CM) targeted at hitting an enemy naval ship grouping.
Besides solving the problem of cruise missiles optimal distribution over the target assignments this work solves the problem of ensuring stability at large. Here, the stability means achieving the probability of hitting the targets, no less than the specified one, for all possible values of uncontrolled factors.
By stability in the article is meant the achievement of the probability of defeat of target tasks not lower than given for all possible values of uncontrollable factors. Thus, the problem is set as:
where d is the vector of design parameters, E(ω) is the distribution function, and P is the probability of failure.
The distribution function E(ω) is constructed with engagement of statistical synthesis operations. A regularity criterion was adopted as a criterion of stability:
where Κ¡ is the Lipschitz constant in the i-th row of the statistical sample of the N volume, Κ¡pos is the specified value of the Lipschitz constant.
To ensure stable design solution, the contracting mapping is necessary, i.e. the Lipschitz constant should be less than one. With this, the less the Lipschitz constant value, the higher the degree of the design solution stability.
At each step of the statistical sample, two variants of design parameters are set. They are necessary for stability condition calculatiщn. The model values of the Lipschitz constant are restored in the class of trigonometric polynomials:
The problem of CM system optimal ranging is being solved at the already obtained stable vector of the design solution (the set of design parameters) yust.
The presented work solved the problem of CM system of optimal ranging, which maintains six target problems. The initial thrust-to-weight ratio and the wing area are assumed as design parameters. The target’s required payload mass, coordinates, speed and course are assumed as uncontrolled parameters.
Three nominal sizes of CMs were considered in the framework of the set problem:
Depending on the uncontrolled factors values, two variants of the cruise missiles optimal ranging were solved, and two distribution functions Ε(ω) were constructed. It is shown that the probability of the system performing the target task appeared to be the same and equals to Ρ – 0,9.
Further, the problem of a design solution selection stable to uncontrolled factors was solved. The stability conditions gave the following design parameters:
Thus, a cruise missile with such parameters solves all the target problems with uncontrolled factors given in the work, i.e. the cruise missile system includes cruise missiles of the same type, and the probability of accomplishing the target problem by the system is 0.9. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aslanov V. S., Yudintsev V. V. Docking with space debris employing the unfolding flexible beam-strap. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 16-24. For risk reduction of the uncontrolled growth of space debris number at the near Earth orbits, it is necessary to remove the most dangerous objects, such as the worked-out orbital stages of rocket carriers and non-operating spacecraft, which may be the sources of space debris. The most complicated stage of passive uncontrolled object's removal from an orbit is its capturing. Selection of capturing technique is determined by the type of space debris and its angular motion. For example, very often the orbital stages are being purposely spin-up around their transverse axis by jet nozzles to guarantee avoiding collision with the detached payload. It complicates capturing the object of such type by the space tug to remove them from the orbit. While employing manipulators or classical mechanisms of a beam-cone type for capturing, when the engine nozzle of a rocket carrier plays the role of the cone, significant overloads may occur in capturing units.
The presented article proposes employ for docking the expanded beam (strip) with aspect ratio. As in the classical docking technique, the nozzle of an orbital stage is being employed. The docking scheme being suggested allows reduce impact forces occurring while docking with rotating objects.
The docking assembly model was developed to study the effectiveness of the suggested scheme. The flexible beam was modeled by the system of solid bodies (beams) connected by cylindrical hinges. To imitate the bending stiffness a torsional spring was being installed in every hinge. The system model was developed using MSC.ADAMS CAE software. The system model was developed in MSC.ADAMS CAE software.
The process of docking with rotating orbital stage, using the three beams variants of large, medium and low stiffness, was analyzed through the developed model. While docking process, the reaction force value in the hinge, connecting the beam with the space tug hull, maximum tug angular velocity and the success of entire docking operation were controlled. The results of modeling confirmed the impact loads reduction while docking with reduction of the beam bending stiffness. The flexible beam will allow employ greater closing-in velocities with uncontrolled rotating objects of space debris to increase the successful docking probability. The beam elastic properties herewith allow reduce the effect of disturbance forces on the space tug while the beam contact with the docking surface of a docking port (nozzle). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kargaev M. V., Mironenko L. A. Static stability of a helicopter main rotor flexible blade at the parking affected by wind. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 43-51. The article is dedicated to the topical issue of helicopter design, namely static stability of an unmoored main rotor blade of a parked helicopter under the wind impact.
The article considers a general case when the wind velocity is directed at an angle to the helicopter longitudinal axis. Velocities and angles of attack of the blocked main rotor's sections are being determined. The authors used experimental data on straight and oblique wings blow-down, as well as circular blow-down of the NACA 23012 profile while determining aerodynamic loads in the blade section, blown by wind flow.
The aerodynamic load, acting in the blade section, is a function of the blade curve, and changes according to the blade's rotation azimuth. Thus, while considering the issue of the blade static stability, the problems on determining the most insecure direction and maximum allowed wind speed of the unmoored main rotor blade under specified position of parked helicopter is solved.
The article considers the blade bending in the plane of least rigidity. The blade torsional deformations are not accounted for while loads determining. It is considered, that the helicopter has main rotor of a common type with hinge mount blades.
Firstly, the solution for the homogenous blade with constant stiffness and aerodynamic characteristics was obtained. The design equation determining the value of wind flow critical velocity in various azimuthal positions was derived. It was established the main rotor blade's stability loss under the wind impact was possible only with oblique blow-down with negative sideslip angles, i.e. when the blade tip position was directed against the wind flow. The wind flow critical velocity minimum value and its corresponding direction were determined. The authors suggest employing the wind coefficient of the blade as a generalized parameter characterizing the blade tendency to the stability loss under wind impact.
Further, the solution for the blade with inhomogeneous parameters was obtained. The value of wind flow critical velocities was obtained by two methods, such as method of straightforward iteration, as well as a method, employing the wind coefficient of the blade.
The article presents the result of the wind flow critical speed computation, performed for MI-8 helicopter main rotor blades, blown-down from the front and back edges. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vyatlev P. A., Sergeev D. V., Sysoev V. K. Holes formation mechanism while laser perforation of metallized thermal vacuum blanket films. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 37-42. Perforation of thermal vacuum blanket (TVB) films is performed to ensure vacuum and protection from electrostatic charges effect.
Method of film materials mechanical perforation is the most widely spread for TVB films perforation. With this kind of processing It is impossible to achieve high productivity and perforation accuracy.
Laser perforation of thin materials is one of the high-efficiency technologies for processing materials, and has a number of advantages, such as increasing productivity and perforation accuracy. This method allows quick adjustment of both the diameter, and perforation step.
Fiber repetitively-pulsed laser with the wave-length of 1,062 microns was selected as laser light source. Dot cutting along the hole outline was selected as a cutting scheme.
The process of fiber laser emission action on metalized polyamide films is accompanied by bushy flame in the operation area. The reduction of laser light power and processing speed herewith results in disappearance of bright light emission and significant increase of thermal influence area width up to 300 microns.
From our viewpoint, daisy chain of the following physical effects could serve as such mechanism:
– evaporation of aluminum coating;
– ionization of its vapors;
– impact of this plasma, combined with light power, on polymer, leading to the hole cutting.
One of the evidences of such hole formation mechanism is performed physical-chemical analysis of the obtained holes' edge. The holes edge was studied by electron microscope of JEOL JSM-5910LV series together with INCAENERGY analytic system. The major results of these measurements revealed the carbon content increase in the holes edge area, while oxygen and aluminum content reduced more than three times. Thus, it can be expected that physical process of holes formation with laser perforation of metallized TVB films takes place under combined action of light power and plasma of evaporated aluminum surface layer on polymer base of the film. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khmelnitskii Y. A., Salina M. S., Kataev Y. A. Spacecraft solar batteries dynamic analysis. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 52-60. At present, the extensive studies of outer space are carried out to obtain scientific, economic and military results.
The solar battery is an important element of a spacecraft since it ensures functioning of its equipment.
The solar battery should have high rigidity at maximum loading factor. The structure rigidity exerts a certain effect on oscillatory process and frequency characteristics while a spacecraft maneuvering. It determines also deformations of a solar battery while its transportation to a specified orbit.
Insufficient rigidity reduces the solar battery efficiency.
The dynamic analysis of solar battery envisages determination of natural oscillations shape and frequency, and a time of the oscillatory process termination.
From these positions, comparison of the two spacecraft “Spectr-R” and 14F150 is being considered.
The finite element models were developed for these occurring while the spacecraft turn along the longitudinal axis were determined.
The inherent characteristics of a solar battery structure were being determined by the finite element method employing “NASSTRAN” software.
To determine values of inherent dynamic characteristics of a solar battery panel a series of simulations of the product dynamics were performed with parameters variation of its mathematical model.
These parameters were determined by elastic and dissipative properties of the solar battery panel.
Comparison of stiffness coefficients values and inertial links damping for these types of spacecraft revealed that the solar panels impact on the dynamic characteristics of these spacecraft was practically the same.
The transient time was of 1000 seconds, which exceeded the admissible values. For the solar battery in the considered configuration, the first mode frequency should be of the order of 0.45 Hz with damping factor of the order of 0.1.
In the considered configuration of the panels, their rigidity characteristics should be 16 times, and dissipative characteristics −3 times greater. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nedelko D. V., Safiullin A. F. Finite element method application for determining water landing parameters of airplanes and helicopters of various types. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 61-72. The problem of safety ensuring while an aircraft forced water landing is topical due to periodic incidents while the flights over the water. According to the European Aviation Safety Agency information, the helicopters that have passed the certification procedure topple when performing water landing. This fact indicates that the process of aircraft dynamic contact water surface is insufficiently studied, and the need to account for the aircraft spatial position parameters while water landing.
Confirmation of compliance with requirements of the airworthiness standards (AP, FAR, JAR) while emergency landing and subsequent sailing of the aircraft is based on the results of model tests, which determine the aircraft behavior, the structure loading, its possible destruction and conditions of the most favorable water landing. The hydrodynamic characteristics of models of aircraft fuselages of ground and water basing in the water landing mode, and helicopter equipment with the system of emergency splashdown are studied. A method allowing study such processes at the stage of preliminary design is the finite element method application. However, validity of the results obtained in this way should be verified based on experimental data to enable further practical application of the experience gained.
The article presents the verification results of finite element models of simple geometric bodies (inclined plate, cylinder). These are simplified models that duplicate the shapes of the amphibious aircraft float, the fuselage of the ground airplane and the helicopter ballonet. Verification was perormed employing the concept of Euler-Lagrangian interaction using the generalized “structure-to-fluid” communication simulation algorithm. For the inclined plate, the lifting force coefficients were determined for various deadrise angles and trim at its gliding on incomplete width. A graphic dependence comparing the experimental and computed values was plotted. The changing of overload at the center of gravity was demonstrated for the gliding cylinder, and comparison was performed with experimental data and approximate analytical theory. In all cases satisfactory convergence of the results was obtained.
A helicopter mathematical model with a system of emergency water landing was developed to compute the depth of the ballonet sinking, which determines the level of hydrostatic and hydrodynamic loads. The general case of driving a helicopter to the approaching slope of the wave was simulated with the presence of the initial slip at the moment of contact with the water surface. Based on the graphical dependence of the ballonet transoms movements, a technique for the computed immersion depths determining was formulated. The visualization of the helicopter position change while the water landing process is demonstrated. Based on the developed finite-element model, the other parameters of water landing of a helicopter with emergency splashdown system (overloading in the helicopter center of mass, loads on the fuselage bottom, etc.) can be determined.
The article shows, that a similar approach can be employed to simulate the process of various types of aircraft water landing, including amphibious and ground ones. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baklanov A. V. Controlling fuel combustion process by burner design change in gas turbine engine combustion chamber. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 73-85. Fuel burning in gas turbine engine combustion chamber entails toxic agents formation. Among them, nitrogen oxides and carbonic oxides, which prove deleterious effect upon a human and environment, present the special hazard. In this regard, the article solves the topical problem on upgrading the existing combustion chamber by changing the design of its burner.
At the first stage of the research, several types of burners, differing by nozzle extension geometry, were studied. The studies consisted in determining toxic agents' emissions concentration in the flame formed by the burner.
According to the results of the studies the inference was drawn that the most acceptable burner was the burner with convergent head piece, since it ensures minimum content of nitrogen and carbonic oxides in combustion products. The decision was made on continuing studies of both types of burners, namely, original with diffuser extension and the burner with convergent head-piece, which demonstrated minimum emission of toxic agents.
It was found that the residence time of the burner with converging nozzle extension in the reverse currents zone was 0.15 ms, and 0.025 ms for the burner with convergent head-piece, which is six times less. Testing results were colligated in the form of mathematical dependence of CO and NO from swirl parameter Sg, which characterizes the degree of the nozzle head-piece opening-out.
During the next stage, the studies on determining the throughput capacity of the burners, as well as the quality of air-fuel mixture preparation at their outlet were performed.
According to the results of the studies, it was revealed that due to the high velocity pressure there is no significant jet spreading behind the burner with convergent head-piece. The jet herewith has the high ejection capability and forms narrow flow core, in which intensive fuel and air mixing occurs. The burner with diffusion extension forms a wide concentration field and its low level, which is explained by volumetric recirculation zone.
The combustion chambers tests hereafter on determining thermal field and obtaining hydraulic characteristics were performed. The measurements showed that at the outlet of the burner with convergent head-piece in the vicinity of thermocouple No 4 the temperature increase was observed compared to the burner variant with diffusion extension. But both cameras ensure temperature field regulated by general requirements.
While next stage the tests of the engines with the combustion chambers under study were performed. The tests data confirmed the reliability of air-fuel mixture ignition during the engine starting. They confirm also correspondence of NK-16ST throttle characteristic to the chambers with both convergent head-piece and diffusion extension in the burner. The obtained data allowed conclude that employing the burner with convergent head-piece allowed reduce emission of nitrogen oxides by 20% and carbonic oxides by 75%. The main characteristics of the combustion chamber can be affected by changes in the design of the nozzle extension in the burner. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mileshin V. I., Semenkin V. G. Computational study of reynolds number effect on the typical first stage of a high-pressure compressor. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 86-98. At present methods of blade machines characteristics are widely used by many scientists all over the world. However, the applied methods of problem setting while flow modeling suppose the boundary layer to be fully turbulent in all regions, and do not reflect transient effects actually in the flow in effect. For the flows with low Reynolds numbers the problem setting with no account for laminar-turbulent transition might lead to significant disagreement between experimental and computational results.
The article presents the results of the computational study of Reynolds number effect on the first stage of high pressure K-8B compressor with the low aspect ratio of the rotor wheel blades (RW) (0.729). The stage has the following key geometry and gas-dynamic parameters:
The values of corrected specific mass flow rate through the stage are related to the values at the design point. The compressor stage regulation allows vary the setting angles of the inlet control assembly (ICA) and distributor, though at the rotor rotation frequencies under consideration (100% and 95%) zero angles were set. The ICA row, RW row and distributor row contain 46, 35 and 76 blades respectively. The gaps at the periphery and hub of guiding devices were assumed as 0.4 mm and 0.6 mm correspondingly in the stage model. The rotor row gap was assumed as 0.5 mm. The value of the total temperature at the input boundary condition is 288.15 K. For Reynolds number decrease modeling the values of total pressure were assumed as Pin = P0, Pin = 0,72P0, Pin = 0,29P0, Pin = 0,21P0, where P0 = = 101325 Pa is the standard atmosphere. The values of static pressure at the periphery were fixed on the outlet boundary condition.
Simulation of 3D viscous flow in blade channel of the stage was performed with ANSYS CFX SOLVER MANAGER in the setting of 3D averaged Navier-Stokes equations (3D RANS). The computational mesh was created with integrated automatic mesh generator ANSYS TURBOGRID and contains 3643432 elements. The solution for the setting with fully turbulent flow was obtained by Menter SST turbulence model. The calculations accounting for laminar-turbulent transition were also performed. For this purpose the Menter SST turbulence model supplemented with γ − Reθ transition model by Langtry and Menter was applied. For solutionconcordance, “stage” or in other words “Mixing planes” option was used at the rotor-stator interfaces. According to the calculation results the stage characteristics degradation between maximum and minimum Reynolds numbers was as follows: adiabatic efficiency η*ad (4%), pressure ratio ( π* ) at the points of max η*ad (2.8%), corrected specific air flow rate (1.52%) at rotor rotation frequency n = 100%, and ∆ max η*ad = 5%, ∆π* = 4.3%, ∆Gcor= 2.3% for n = 95%. Thus, the shift of characteristics corresponding to lower Reynolds numbers occurs to the area of reduced flow of η*ad and π* . The transitional model addition affects these differences as follows: ∆ max η*ad= 3.9%, ∆π* =2.2%, ∆Gcor= 1.6% for n = 100% and ∆ max η*ad =3.7%, ∆π*=2%, ∆Gcor= 1.6% for n = 95%.
Comparing to the experimental results, obtained for n = 95%, application of transitional model of turbulence increases significantly the accuracy of the numerical study. Namely, deviations between experimental data and calculations with transitional model by values of max η*ad pressure ratio at the points max η*ad is less than 1%, while for standard SST model these deviations are of about 2% for maximum Re number, and 3.5% for minimum Re.
Comparing the fields relative to Mach numbers for two models (SST and SST γ − Reθ ), the basic difference in the flow while laminar-turbulent transition modeling consists in qualitatively true modeling of the processes occurring in the boundary layer. In this case, laminar boundary layer near the front edge of the blades, laminar separation and attachment really exist. Turbulization at the rotor wheel blades occurs at the shock wave location, after which the boundary layer already has turbulent structure for the most part with preservation of a very thin laminar layer. Besides, the changes in flow through the radial clearance in the rotor wheel are being present. For γ − Reθ “bubble” flow-over while Re number reduction slightly reduces its size. The separation near the back edge herewith becomes more intensive. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezrokhi Y. A., Khoreva E. A. Estimation of inlet airflow non-uniformity effect on turbofan thrust. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 99-108. The article considers methodical approaches to developing mathematical model using “parallel compressors” method, intended for estimation of inlet flow non-uniformity effect on aircraft engine basic parameters. On the example of a two-shaft turbo-jet engine calculation at two characteristic cruise modes the results of calculated estimation, where the base value of σst and averaged value of σav stayed invariable, were presented. Parametric calculations herewith were performed for each selected relative value of the reduced pressure area.
It was demonstrated that degree of full pressure inlet non-uniformity effect on the engine thrust at the two considered modes differs significantly. Thus, if at subsonic mode this estimation could be reduced to accounting only for the effect of reduction of the averaged value of the total pressure at the inlet, while at supersonic cruise mode such reduction use might lead to considerable errors. With invariable values of pressure recovery factor at the engine entry, corresponding to the flight speed for the typical air intake, external compression σst and averaged value σav, the flow non uniformity factor Δσnu affects mainly the thrust. The degree of this parameter effect herewith depends significantly on the difference of sst and sav.
The obtained results of calculated estimations of temperature field non-uniformity at the engine inlet effect revealed that the dependence of relative thrust reduction only at the cost of relative heating was similar for the two considered modes (transonic maneuvering and supersonic flight). At the transonic mode herewith, corresponding to higher values of the reduced rotation frequency of both compressor stages, the thrust decay occurs less intensely due to relatively smaller decrease of air flow rate through the engine with reduced rotation frequency decrease due to air temperature rise at the inlet. As for the difference between the values of total thrust decay , which does characterize the effect of the input temperature field non-uniformity, with the increase of relative heating at the transonic mode it rises more intensively. It is explained by the fact that at this mode due to the less difference between air consumptions in air-gas channels of «parallel compressors» (more «dence» location of pressure downstream brunches) the speeds difference and, consequently, static pressures between the flows is much greater, than at the supersonic flight mode, which stipulates the higher losses level while these flows interaction. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Smirnov P. E., Khartov S. A., Kashulin A. P. Experimental study of radiofrequency cathode-neutralizer. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 117-124. High specific impulse and low mass-flow rate of ion thrusters (IT) make them increasingly popular choice as a spacecraft propulsion system. Recent missions demonstrate the efficiency of these thrusters in such missions as orbit correction and exploration of Solar system. Moreover, there are many developing ideas of creating spacecraft with IT for wider spectrum of missions. However, IT needs to have a longer operation time, due to the small thrust (about several mN).
As a rule, such thrusters failure occurs due to the destruction of Ion Optics electrodes or failure of electron source. IT needs electron sources as a main cathode (for plasma producing), and as a cathode-neutralizer (to neutralize potentials of ion beam). Hollow cathodes are most used devices for Ion propulsion applications, due to low gas consumption and high electron current density.
Application of lanthanum hexaboride or tungsten with BaO impregnating as an emitter material, leads to the necessity of strict sustenance of hollow cathodes operational parameters. Interaction of emitter material with a small quantity of poison gas leads to its surface contamination and, as a consequence, to decreasing of the recoverable current even down to zero. It leads to more requirements to the gas purity, and hollow cathode handling prior to its placement in space. Moreover, to ensure effective operation, the emitter should be heated up to 0.6-0.8 of its melting temperature by the external heater, which, in turn, causes the emitter material evaporation (life span reduction), power consumption increase and longer cathode start-up procedure.
The problems of high reliability of traditional electron sources for ion thrusters led the authors to the idea apply them as cathode with plasma high-frequency discharge. In such device, plasma is generated and sustained by radiofrequency induction discharge. The absence of “loaded” (high temperature, powerful flows of charged particles) electrodes eliminates all problems of the cathode long-term operation provision. As with hollow cathode, the bulk plasma volume acts as an electron emitter, which allows generate high electron currents. The article describes the scheme of the prototype of this device, and the results of its experimental development. Currents generated by the high-frequency cathode were achieving up to 1.7 A at the input power of 120 W. Effectiveness evaluation of the high-frequency cathode is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abdulov R. N., Asadov H. G. Optimization of unmanned aerial vehicles detection in conditions of signal-to-noise ratio variation. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 125-131. The problem of illegal unmanned aerial vehicles of various types detection and identification consists in their low flight heights, small sizes and high maneuverability. The presented article analyses the interrelated optimal selection of detection probability figures in the UAV-Radar system, corresponding to the minimum value of the signal-to-noise ratio at the output of the radar receiving part, i.e. the worst conditions of the UAV detection. The authors suggest a new setting of the problem, associated with several pulses detection at the radar input while the signal-to-noise ratio changing dynamically. The article considers the situation when the detection probability grows with time, and the integral of the sum of detection probability and false alarm probability is equal to a certain constant. In conditions of dynamically changing signal-to-noise ratio with account for the accepted condition of constancy of the integral of the sum while preserving the mutually inverse by nature character changing of detection probability and the alarm probability the problem of optimal interrelation above said probabilities values calculation the is being set. The optimization criterion was formulated in the form of the integral of the well-known expression, determining the interrelation between the signal-to-noise ratio minimum probabilities and false alarm. The gist of the formulated optimization problem consists in finding such probability dependence of false alarm from the detection probability in the series of operations of radar detection with growing detection probability, at which the minimum of the integrated value of minimum signal to noise ratios is reached, ensuring detection of point objects at each radaroperation. Based on the performed analysis the authors obtained the functional relationship of the false alarm probability from the detection probability for scenario, when a pinpoint target in the course of radar detection with growing detection probability is being detected at minimum achievable figure of integrated signal-to-noise ratio at the radar receiver input.
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Mamedov I. E. Photometric informational method for unmanned aerial vehicles localization. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 132-138. One of major factors affecting the successful UAV performing reconnaissance tasks is the possibility of its coordinates exact localization. The UAV position estimation in such systems is usually performed employing such features as reference points, margins or other images informative elements. Application of such characteristic as reciprocal information for this purpose is also possible. The major shortage of these methods consist in complexity of this function computation in real time scale. The presented article suggests the method, generalizing the main features of localization techniques based on reciprocal information calculation. In contrast to the well-known solutions, localization with the suggested technique is performed based on both information characteristics and optical illuminance characteristics of the analyzed images of various formats. The resemblance of real scene herewith with geo-referenced image is computed by subtracting them from the information characteristics, and for accuracy and reliability of the obtained result, the localization is performed based on multi-format geo-referenced images of the object. The localization problem is solved with this method as a problem of minimization of difference of the total volumes of information, obtained from the real object and reference image in the mode of studying the multi-format frames while meeting some additional condition, specified on total illuminance of the studied and compared images. As applied to the considered problem of the UAV localization, the obtained solution ensures maximum difference of estimations of information volume in the ground scene under study and geo-referenced image. The author concluded that the optimal selection should be considered as such a desired functional dependence, which differs to the greatest extent from the calculated function characterizing the studied extreme localization mode. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Spirin A. I. Flight data analysis as an operational decisions making basis of the long-term operating orbital stations usage manual. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 139-151. Space mission control is an integral part of the control process. It allows obtain a fair presentation on the actual state and functioning of constituent parts of a spacecraft (SC), the degree of tasks implementation and its reaction to control actions.
As a rule, two tasks are solved while controlling. The first one consists in predicting the SC and crew abilities to perform the current flight tasks based on current data, and the second one of no less importance is to detect timely a failure onboard a SC and take measures to its elimination at short notice.
The analysis of the SC onboard systems state adds to the control, but this process is more complicated and it is aimed at revealing cause-and-effect relations of the control parameters both with each other and with external conditions. This analysis is performed for predicting the onboard systems state over the planned flight stages to reveal undesired tendencies in control parameters behavior, as well as for analyzing and revealing the causes of divergences and failures of the onboard system operation. The analysis of the onboard systems states is performed as a rule out of the bounds of a SC operative control loop.
For long-term orbital stations' (LTOS) the analysis of the onboard system state is particularly urgent due to the necessity of ensuring long-term operation in conditions of known restrictions on their structure changing. The flight data generalization and their analysis allow reveal the causes of divergences of the onboard systems states, elaborate recommendations on their elimination of reducing their negative effect, as well as elaborate operational decisions on optimization of the onboard systems operation modes, rational resources consumption, ensuring thereby long-term and effective operation of the LTOS.
The article presents methodological approaches employed for the of onboard systems state analysis with account for collateral data. The operational decisions examples, implemented based on the International Space Station flight data analysis, are considered for the events such as:
– parry the negative impact of the jets of orientation engines of transportation vehicles on solar batteries panels (SP);
– reduce fuel consumption during the SP effectiveness evaluation;
– improving the heat transfer of radiators of the thermal mode provision system during the «solar orbits» periods. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kyaw Z. L., Moung H. O. Development of wind velocity estimation method using the airspeed. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 152-159. The method suggested in this paper provides estimates for the three projections of wind velocity in earths normal coordinate system using satellite navigation systems (SNS) data, as well as on-board barometric airspeed measurements. The wind speed and its direction are assumed constant for a flight leg of 50-60 s duration. This means, that for the given time interval projections of the wind velocity values on the axis of the normal earth coordinate system are constant. Further, the object and observation models are presented, as well as the identification algorithm accuracy characteristics, obtained from the simulation data processing. The airspeed measuring error effect on the wind velocity estimation is also under discussion. The results, showing the accuracy of wind velocity estimation depending on the constant velocity measurement errors, are presented.
The analysis shows that horizontal projections of wind velocities are estimated with high accuracy (relative errors of 13%), but a certain time interval to obtain the proper degree of identifiability is necessary. After this, the accuracy of estimating the horizontal projections of wind velocities remains at a decent level, and does not depend heavily on the increase of the speed measurement error. The wind vertical projection estimation herewith leaves something to be desired. It makes 3040% even at zero flight speed error, and increases considerably with an increase of speed measuring error. Thus, we may conclude that the suggested method can ensure the good accuracy for estimating the wind velocities along the horizontal coordinate axes, and it is not applicable for estimating the vertical component of wind velocity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lebedeva N. V., Solov'ev S. V. Intelligent systems application while spacecraft flight operational control. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 152-159. To perform automation of a spacecraft state control, it is necessary to define the scope of tasks, which are most dangerous from the viewpoint of their accuracy of estimate. Intelligent systems application whileoperational flight control does not assume the complete waiving from human in the control loop. It should complement his activities by in-depth and rapid evaluation of a vast amount of information, and help to elaborate the correct reaction to the current state of a spacecraft.
While operational efficiency computation, the nominal time t and its technological delay ∆t , spent for evaluation, is assumed as the main control criterion. This technological delay is associated with the time of data receiving from the spacecraft. The spacecraft normal operation evaluation is important as the main reference point for monitoring of its state changing.
While various operations execution the type of commands issued to the onboard systems to ensure the operation execution, capability of their issuing, as well as the ways of technical evaluation of the state of their execution are accounted for. For control automation, it is necessary also to account for the pre-planned possibilities of organized (nonrandom) effecting affecting its state. From the analysis viewpoint, the flight operation execution switches the spacecraft to a new state. Evaluation of the flight operation and the new state of the spacecraft is the purpose of the flight operation controlling.
The monitoring process includes also performing diagnostics of the spacecraft state. More than one point of its state herewith is determined for the current time (interval). Intelligent system application allows employ all previous diagnostic results and represents the dynamics of the development of the process of changing the technical characteristics of the spacecraft in the past, which can be used to the forecast systematic correcting and increasing its validity.
Operation of the intelligent system in real time mode will allow increase the response rate to anomalies occurrence and their development in time with accurate fixation of the drift of data deviation development. An essential advantage of such systems can be the immunity to accidental failures, such as information loss, as well as the determination of non-obvious changes, which might become a forerunner of failures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pigalova E. A., Abramova A. A., Kurnikov N. A. Plasma welding application prospects while airplanes of mig brand production as one of the methods to reduce welding deformations. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 172-183. Welding is a complex technological process followed by occurrence of internal residual tensions and deformations of a welded structure.
While producing aircraft It is essential to reduce residual tensions and deformations, since:
– the structure's deformations affect an aircraft external aerodynamic contour reducing its aerodynamic characteristics;
– residual tensions sum up with tensions from external loads on the structure, leading to its destruction;
– residual tensions form volumetric stressed state in separate metal volumes, which complicate plastic deformation of a metal and contributes to its transition to brittle state, leading to local destruction of a structure.
This work is devoted to experimental research on automatic plasma welding application instead of argon-arc welding as one the methods for welding deformations reduction while aircraft structures fabrication.
Plasma welding is the welding performed by directed flow of plasma arc. The plasma arc is characterized by the high temperature (up to 30,000°C), and a wide range of its processing properties. It has much in common with argon-arc welding technology.
The main features that distinguish the plasma arc from the conventional one are:
Conclusion: the plasma arc is more concentrated, powerful and universal source of heating in compared to the conventional one.
The conducted pilot studies consist in comparing parameters of the samples welded by both automatic argon-arc and automatic plasma welding. Based on the performed work, the following conclusions were drawn:
Based on the above said studies at NAZ “Sokol” the decision was made to implement automatic plasma welding. A new installation for sheets butt-joint automatic argon-arc and plasma welding was developed.
The installation consists of:
The interface of control panel software is intuitive and provides the following functionality:
The effect of implementing the plasma welding instead argon-arc:
1) Higher labor productivity in view of the higher welding speed (by 3-5 times).
2) Time consumption reduction for products leveling after welding (by 50-70%) due to minimal residual deformations in the weld seam due to more concentrated heating source.
3) Time consumption reduction for welding modes testing (by 50-70%) due to the the stored base of welding programs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golovnin S. M. Risk of problem solution skills loss by civil aviation pilots in uncertainty conditions. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 184-190. Modern air transportation system is characterized by the great dependence on human, all its elements safe functioning determine the very same “human factor” playing a big role in management and stability of the entire system. In the course of time and aviation industry development, the role of the human factor in aviation accidents is being varied considerably. If for old aircraft, which were difficultly controlled and unreliable the human factor share was 5–7%, in the middle of the middle of the last century it was about 50%, and at present of the human factor is about 80% with the uptrend.
To reduce the risk of an aviation event, the Concept of Crew Resources Managing (CRM), based on the provisions of the human factor, is being actively implemented in modern civil aviation. This is a system of measures aimed at enhancing flight safety and effectiveness by the right implementation of human, technical and information resources, as well improving interaction within the crew, and the crew with the personnel of the other CRM components. CRM is an of practical implementation of the human factor principles.
The human factor as the cause of aviation event implies the human inability to react (interfere with) timely to an evolving or created emergency situation to avoid or minimize of this event aftermath.
One of the most important characteristics of a person is the response time of his reaction. In general, the response time is the time that passes from the moment of the an irritant occurrence to the motional response ending. In civil aviation, the ability to respond to irritants (signals, air traffic controllers' commands, aircraft cabin situations) is instilled in the early stages of training in flight schools. However, the practical development of reactions to events undoubtedly plays an important role in the development of the reaction rate under real flight conditions.
For this purpose, training programs for cadets include tasks for training with a list of events, which are practiced on simulators and imply the occurrence of the cadet's correct response to avoid an emergency situation development.
However, while delivering classes with cadets who are commissioned for a new type of aircraft after flight school graduation, it was noted that in the case of a series of one-type trainings, cadets began foresee a situation that wouldl be set by the instructor and developed while training process.
Thus, the effect of “suddenness” vanishes, and after all, failures or other predicaments, which may occur in flight, cannot be predicted in real flight conditions.
This regularity and foreseeing the possible scenario of situation development is able to abate significantly the pilots skill to respond and solve the unexpected problems and reduce the need for analysis and correct decision-making regarding a particular situation. As a consequence, the pilot's main skill “to fly a few seconds ahead of the aircraft” will be blurred and will subsequently be left without development, which will affect the further safe aircraft operation.
The following experiment was conducted to simulate alike situation with the cadets on the simulator. Ten cadets underwent a total of twenty training sessions, of which in 10 training sessions they knew that a simulated collision with the bird (imitation of broken glass) would be planned, and in 10 other cases the task for training did not indicated the planned collision with a bird.
The results were being recorded as follows: the training number and the number of people who could not properly perform the procedures while collision with a bird (imitation of broken glass) were recorded.
Thanks to uncertainty conditions modeling in virtual space (training device, simulator), these skills can be developed on the ground, preparing the pilot for action in almost any situation, and it does not matter whether the situation is caused by a person, a vehicle, or environment. Skills of action in the face of uncertainty will help the pilots in any case to make right decision and eliminate the problem in time. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ismagilov F. R., Zarembo I. V., Kalii V. A., Vavilov V. E., Miniyarov A. K. Specifics of permanent magnet synchronous motor development for fuel pump of perspective flying vehicles. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 191-202. Electric motors are one of the main actuating element ensuring aircraft systems functioning. Traditionally, they are employed in fuel pumps, oil pumping pumps, hydraulic stations, automation systems, as fans drive, and wing-flap systems. The variety of problems solved by electric motors on board the aircraft, makes them almost one of the main consumers of electric power.
Currently, several types of electric motors are employed in aircraft fuel pumps, such as DC motors with brush-collector unit, induction motors, inductor and reactive motors, permanent magnet synchronous motors (PMSM) with direct start, and brushless direct current motors (BLDCM). All the listed motors have problems related to energy efficiency and mass and size indicators.
Thus, the main promising motor version for employing in aviation fuel pumps at this stage is the PMSM. A number of scientific and practical works are devoted to the development of the PMSM for aerospace systems. In particular, the specifics of field simulation of the PMSM for aircraft air-conditioning systems and general approaches to PMSM development for aerospace applications are considered. The works are devoted to the study of the PMSM magnetic systems and solving the problems of creating a PMSM control system development. The design features herewith of PMSM for fuel pumps are not disclosed in the literature. Although this type of motors has a number of distinctive features, such as working conditions in the field of low negative temperatures, working capacity at low voltage, employing of graphite bearings, etc. All these specifics do not allow employ the results of the works to the full extent.
Thus, the purpose of this article consists in analyzing the design features of the PMSM for fuel pump by developing and examining the PMSM for fuel pump with concrete geometry with account for real operating conditions and evaluating the prospects for the development of the PMSM for fuel pump. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nadaraia T. G., Selivanov A. I., Shestakov I. Y., Fadeev A. A., Vinogradov K. N. Hybrid energy storage device in power supply system for prospective spacecraft. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 202-209. The article presents the improved version of spacecraft power supply system by rational selection of the hybrid power plant basic elements. Power supply system is the most important onboard system from the viewpoint of energy supply and reliability. Failure of this system entails failure of the whole spacecraft.
The main types of power plants, such as a combination of solar and chemical batteries, installations based on various physical phenomena, and electrodynamic tether systems, as well as nuclear ones are known.
Rational selection of the power-plant basic elements to solve specific problems allows improve technical, mass-and-size and cost characteristics of a spacecraft in total.
The improvement of the power supply system energy efficiency is achieved by special schematic architecture and joint application of chemical and kinetic energy storage devices. The hybrid energy storage device will allow maintain the required energy supply of the onboard equipment and compensate peak energy consumption onboard a spacecraft. This energy storage device includes ionistors. Ionistors serve to compensate fast transients while the installation start-up in orbit. Compensation of the occurring kinetic moment is realized by installing two energy storage devices operating in antiphase. Application of contactless, magnetic, high-temperature super-semiconductor suspension in the flywheel allows significantly reduce mechanical losses and increase the storage time of the stored kinetic energy.
The principle of the above said installation operation in both energy storing mode and energy return to the system to consumers' mode is described. The hybrid energy storage device operation in the process of energy return takes place with rotation speed changing, which leads to the necessity of solving the problem of obtaining the AC of stable frequency at the output. This problem is being solved directly by rotating converter or a specialized inverter. Smoothing the peak loads on the battery by ionistors and the lack of brush gear increase the lifespan of the hybrid energy storage device.
Indicative computations show that application of the hybrid energy storage device allow improve mass-and-size characteristics of the power supply system by 24%. The suggested approach will be employed in further activities associated with enhancing the energy-mass perfection of the spacecraft power supply system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galkin V. I., Galkin E. V., Paltievich A. R., Preobrazhenskii E. V., Borunova T. V. Analyzing technological schemes of production of “FRAME SEGMENT” type parts. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 210-220. The article considers methods for frame segment obtaining from the B95 alloy by isothermal forging. This method allows obtaining forgings with minimum allowance for machining and requires value of punching force. Isothermal forging can be a more productive alternative to the now employed cutting operation with NC machine tool. The above said alloy is a certified material for aircraft industry and has a high specific strength. One of the B95 specifics consists in rather narrow deformation temperature region. On the one hand, herewith the forging temperature should be selected as maximum to reduce the required force, and on the other hand, the deformation heating-up may lead to overburning, i.e. irreparable damage of the material, characterized by drastic mechanical properties deterioration. To solve this problem, the authors propose to reduce the deformation loading of the material, which can be ensured by controlling the stress-and-strain state and heating temperature of a workpiece while forging.
The stress-and-strain state of temperature fields analysis was performed with engineering software complex Deform, based on finite element method. Deform software found wide application for the analysis of metals pressure shaping. It allows reduce the design period of the process and cost price, as well as increase the quality of production.
In the presented work several options of isothermal forging of a frame forged piece made of B95 allow were studied with finite element method. While modeling, the initial temperature of the process was being varied, and forging tools of various geometry were employed, as well as the auxiliary operations number. Workpieces of various cross-sections, such as circular, square and rectangular ones were used. The initial workpiece position in the stamp was accounted for. For all cases under consideration, the deformation ratio exceeds the permissible value of 60%, and the process temperature was non-uniformly distributed over the forging cross-section. In a number of cases the conditions that could lead to metal burn-out were observed. It was found, that the most rational scheme is the scheme of isothermal forging, in which a rectilinear pressed rod was used as a billet. Its cross-section area was equal to the section area of the frame forging, and the length of the shelves was 3 mm shorter. This scheme application allows produce forging with equivalent strains of no more than 60%, and allowable deformation heating, which does not lead to the of B95 alloy burnout. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Antipov V. V., Dobryansky V. N., Korolenko V. A., Lur'e S. A., Serebrennikova N. Y., Solyaev Y. O. Evaluation of layered aluminum-fiberglass plastic effective mechanical characteristics in conditions of uniaxial tensile. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 221-229. The article presents the results of laminated aluminum-fiberglass composite material, formed by thin layers of aluminum alloy and fiberglass, mechanical characteristics modeling. A modified analytical model of layered material accounting for the presence of metal elastic-plastic layers in the composite structure with bilinear defining relationships is being employed for calculations. For the case of uniaxial tensile, the layer-by-layer analysis of the composite strength is being performed with account for residual tensions formed while the material fabrication. The Tsai-Hill strength criterion was used for fiberglass layers. The moment of yielding commence in metal layers is being determined by Mises criterion. The calculation results determined effective strength characteristics, yield stress and strength limit of composites in conditions of uniaxial tensile. The good agreement of calculation results and experimental data within the 90% of accuracy limits was shown.
The effective Young's modulus of the material in the calculations was 51.5 GPa (49 GPa in the experiment). The apparent yield stress of the composite, associated with the appearance of plasticity in the layers of aluminum, was 230 MPa, which in fact coincides with the experiment. The composite ultimate strength in calculation was 540 MPa (585 MPa in the experiment). In fact, it follows fr om the calculations that the yield stress of metal-polymer composite is determined by aluminum layers yield stress, while the strength limit is determined by the strength lim it of fiberglass layers oriented in the direction of load action. The proposed model allows evaluate the effect of residual tensions on the material mechanical strength characteristics. The results of calculations established that the residual tensions might lead to the composite mechanical properties degradation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kalugina M. S., Remshev E. Y., Danilin G. A., Vorob'eva G. A., Telnov A. K. A method of light alloys reinforcing by aero-thermoacoustic treatment for aerospace industry. Aerospace MAI Journal, 2018, vol. 25, no 2, pp. 230-239. The article studies the possibility of developing technological basics of higher mechanical properties of aluminum casting alloys ensuring, and wrought aluminum alloy while employing aero-thermoacoustic treatment (ATAT).
The share of aluminum allows employed in aviation industry is high. Thus, both casting and wrought alloys find application in aerospace industry. Casting aluminum alloys are used for containers and tanks production. In machine building such casting aluminum alloys as silumin are widely spread.
Aluminum wrought alloys present great interest, due to their higher mechanical properties. They are used for aircraft hulls manufacturing. The above said alloys are employed for manufacturing prefabricated shells of aircraft hulls, representing rigid encasements of rather rigid sheet material, which should resist normal and tangent forces and carry all types of loads.
ATAT employing enables increasing the strength of silumins about 1.4 times, practically with preserving elasticity at the initial level or its slight reduction. Significant holding time reduction was observed as well.
The article studies ways of increasing strength characteristics of extra-high tensile wrought aluminum alloy without significant loss of plastic properties of the material.
The article studies ways of increasing strength characteristics of high-strength wrought aluminum alloy without significant loss of plastic properties of the material.
The ATAT effect on the structure and properties of aluminum casting alloys was revealed, which could be associated with the process of micro-plastic deformation and partial recrystallization while treatment, with diffusion processes acceleration, which ensures grinding of solid solution grains. The redistribution and reduction of macro and microstrains in the material significantly affects its properties. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aslanov V. S., Yudintsev V. V. Parameters selection of space debris removal system with elastic elements by cable towing. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 7-17. There are more than 1500 large artificial objects on the near-earth orbits, while only 7% of then are active spacecraft. The remaining objects are space debris. The greatest hazard is presented by the large space debris, such as non-functioning satellites, final stages of rocket carriers, staying on the orbit. Their destruction can lead to grave aftermath, since collision of such object with other the objects and fragments may lead to significant increase of the number of small debris, which, in its turn, can lead to impossibility of safe employing of some near-earth orbits. The space debris removal is one of topical problems, which humanity will have to solve in the nearest future.
A method of space debris removal, and transportation system parameters are determined in many ways by the properties of the garbage being removed. Objects capture and removal by tether systems is one of the prospective methods of large objects, such as non-functional satellites of rocket stages, removal from orbit. The removal of a non-functioning spacecraft with flexible elements herewith is a more complicated task, since the possibility of oscillations of elastic structural elements, such as solar batteries panels should be accounted for, which may lead to their destruction and greater clogging of near earth space.
The article considers cable transportation of a large-sized object of space debris with elastic elements, such as solar batteries. The goal of the work consists in studying the mutual effect of tether oscillations and oscillations of flexible elements while transportation active phase. The article presents the developed mathematical model of the system, consisting of space tug and towed space debris with flexible elements. It considers the simplest case when only a constant thrust force effects the tug. No other forces and moments (such as gravitational) are accounted for.
The transported space debris should not be destroyed while towing, and its attached elements (solar batteries) should not tear away. Otherwise, it may lead to greater clogging of space. To analyze the possibility of destruction and selection of such system parameters that will exclude the space debris structure destruction, mathematical model was developed. By dint of this model, the analytical expressions allowing select the tether rigidity depending on parameters of space debris and mass of the tug were obtained. The article demonstrates the existence of critical tether rigidity, that should be avoided while transportation system parameters forming. Direct numerical integrating of the initial equations of the motion substantiated all analytical and numerical results presented in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Guryanov A. I., Kalinina K. L. Studying an atomizer for rain imitation while aircraft engines certification. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 18-27. The purpose of the study is creating an atomizer for aircraft engines testing while ingress of rain, as well as checking the sample for conformity to the standard requirements for testing facilities adopted for aircraft engines' certification.
The review of fluid spraying problems and methods, which formed the grounds for further selection of the liquid spraying scheme, was performed in this research work. The paper presents the description of the technique for the pursuance of the pilot studies of the atomizer with determination of the parameters such as flow coefficient; water distribution irregularity ratio; rooted angle of a drip stream and drops distribution over the diameter with computation of the average median diameter. It presents also the scheme of installation for complex study of a water drip stream characteristics.
Experimental studies of atomizer prototype models were performed according to the above said technique for the purpose of increase integral parameters of the efficiency, as well as compliance check of range of drops diameters from 0.5·10-3 to 7·10-3 m, and the value of average median diameter of 2.66·10-3.
The tests allowed revealing the relationship between the geometric characteristics of atomizers and drip flows being obtained. Development of the most suitable prototype of atomizer allowed obtain the drops within the certification range with average median diameter of 2,656·10-3 m.
The results of the work are as follows: the problems of rain imitation were analyzed, the technique for the atomizer testing was developed, and the atomizer design was offered and substantiated. Experimental studies of parameters of the above said atomizer were performed design, and its conformity to certification requirements was confirmed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shorr B. F., Buyukli T. V., Shorstov V. A., Bortnikov A. D., Sal'nikov A. V., Frolov V. N., Serebryakov N. N. Developing calculation method for forced vibrations of turbomachines of a blisk type blades. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. . The subject of the article “Developing calculation method for forced vibrations of turbomachines of a blisk-type blades” by Shorr B.F., Buyukli T.V., Shorstov V.A., Bortnikov A.D., Salnikov A.V., Frolov V.N. Serebryakov N.N. is the blades of a blisk-type rotor wheels.
The research topic is the effect of amplitude-dependent damping in the material of blades on amplitude of the steady-state resonant vibrations.
The goal of the work is definition of the non-stationary components of the aerodynamic forces and resonant stresses amplitudes in the blades at steady-state vibrations.
The article employs the following assumptions: only the steady-state vibrations amplitudes are being computed. Aeroelastic phenomena relating to blade deformation (both oscillations' excitation and damping) are neglected, i. e. gas exciting forces are defined according to the geometry of air-gas channel elements at a specified operating mode regardless of blade vibrations. Mechanical damping in blades material is amplitude-dependent; i. e. blade behaves as a physically heterogeneous body in the sense of energy dissipation, which heterogeneity depends on variable tensions distribution at each form of vibrations. Damping properties are verified by dynamic tests of samples at various excitation levels and frequencies.
The methodology of the work includes a sequential computational study, which consisting of initial normal modes analysis with definition of the operating mode with possible resonances. It also accounts for of the non-stationary components of the aerodynamic forces definition by solving the Navier-Stokes equation at the operating mode of interest, transferring these components to the nodes to the mechanical finite element model of the blade. Finally, the extraction of the harmonic components of the force, and solving the problem of steady-state vibrations of the blade with amplitude-dependent damping.
Calculations revealed that employing of the constant decrement of oscillations might lead to incorrect results. The difference between calculated amplitudes of the vibratory stresses in the considered example was 25%.
Conclusions were drawn on the method structure, as well as that the considered example of calculating the rotor wheel forced vibrations at resonance with the 13th harmonic of the flow circumferential irregularity shows the utility of accounting for the dependence of the energy dissipation factor in the material on the vibratory stresses amplitude.
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Il'inkov A. V., Gabdrakhmanov R. R., Takmovtsev V. V., Shchukin A. V. Effect of centrifugal mass forces on heat transfer when airflow of concave surface with transverse projections. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 39-48. The article presents the results of a pilot study of average heat transfer on a concave surface model with regard to the cooling systems of the leading edge of a gas turbine engines turbine blade with spanwise semi-cylindrical ribs in turbulent flow. Relative curvature parameter was being varied by variation of the momentum thickness. Heat transfer has been studied employing a gradient method based on Fourier-Newton law. A test section was a plane channel of 140 × 100 mm consisting of a straight section and a 90° bend. The concave surface of the channel and the object under consideration had a radius of curvature Rw = 500 mm.
The visualization results revealed that when an undisturbed fluid flowed past the first spanwise rib, the reattachment length behind this rib depended on the surface curvature parameter. The latter is the ratio of the momentum thickness to the surface curvature radius. The increase in this parameter fr om 1.38 · 10-3 up to 2.5 · 10-3 resulted in the average of 1.6 times reduction in the reattachment length.
This result derived fro m flow visualization has been satisfactorily confirmed by the distribution of local heat transfer coefficients between the ribs. The reattachment length characterized by the peak heat transfer reduced approximately by 1.4 times. No effect of centrifugal body forces on heat transfer in the flow around the second and third ribs has been observed.
It has been shown that in the case of combined effect of centrifugal body forces and spanwise ribs on heat transfer, these factors do not meet the additivity concept of individual effects due to their mutual coupling. In the considered case, the effect of streamwise curvature of the concave surface was observed only behind the first spanwise rib wh ere the momentum thickness was large. This effect was suppressed further downst ream byboundary layer breakup caused by spanwise ribs. The contribution of centrifugal forces to heat transfer enhancement at a given surface curvature radius can grow if the rib height is decreased while the streamwise rib pitch remains constant. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Marchukov E. Y., Polyakov K. S., Kulalaev V. V., Petrienko V. G. Computation of magnetic liquid flow in annular channel of magnetic-fluid seal of a shaft with high-speed wall. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 49-56. Purposes and objectives of the article consist in the following: formulating hydrodynamic boundary problem of computation of magnetic-fluid seal (MFS) parameters, which belong to the group of noncontact slot seals operating as a hydraulic lock. While developing MFS the annular packets of conducting magnetic brushes were used as magnetic field concentrators instead of teeth. A magnetic fluid resides between the bristles of these brushes in a narrow annular channel. Such a seal gives the minimum friction between the interfaced parts. Numerous calculation methods for the abovementioned hydrodynamic boundary problems developed historically almost independently from each other. General principles for creating numerical methods acceptable for all hydrodynamic boundary problems in general were slated. The aggregate of these concepts and methods allows eventually reduce the algorithm for solving complex hydrodynamics boundary problems to algorithms for solving simple problems of standard structure. An integral relations method employed in this work was developed based on conservation laws and eventually reduced to ordinary differential equation solving. At the domain boundary herewith the boundary conditions are specified both at the rigid wall and the boundaries through which the flow inflows and outflows. Additionally, adhesion conditions are specified. The presented article formulates the new boundary conditions of tracking-concatenation of viscous incompressible flow for internal flows in narrow annular channels. It gives mathematical formulation of the boundary problem for viscous incompressible magnetic flow with possible internal backflows, which detection experimentally is impossible. The boundary problem was set and algorithm for computation of viscous magnetic liquid flow field in the annulus with movable walls of the magnetic-fluid seal (MFS) by the structured method with the exact fulfillment of the boundary and initial conditions was presented.
The article shows that application of mathematical apparatus for solving the boundary problems by the structured method allows calculate in total parameters of the magnetic liquid flow: heat flows, coefficients of friction, heat transfer and distribution of these parameters through the radial clearance of annulus, revealing the areas of potential backflows.
The results of this work may be useful while developing and computing new type of magnetic-fluid seals (MFS) for high-speed shafts of structures and units for various industrial purposes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezrokhi Y. A., Kalenskii S. M., Morzeeva T. A., Khoreva E. A. Accounting for the effect of the border layer at the inlet to the fans while integrating the distributed power plant and a flying vehicle. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 57-66. The article presents the analysis of a distributed power plant concept for perspective long haul passenger aircraft, which is intended for ensuring more deep integration of a power plant and a flying vehicle, as well as enhancing its fuel efficiency.
While employing an aircraft engine of such kind, separate modules of a power plant may be installed both in the engine nacelle and inside an airplane fuselage, made according to a “flying wing” scheme.
A portion of a boundary layer, formed at the surface of an aircraft, gets into the inlet plane of fan modules, located at the top surface of the fuselage.
The variant of a submerged engine inside an aircraft assumes the presence of a rather long curvilinear intake channel, in which local separations and vortexes inevitably occur. It leads to additional losses of full pressure at the engine inlet.
The article considers separately the effect of two main factors on the engine thrust, namely, the drop of overall level of the total pressure at the engine inlet and its non-uniformity.
To evaluate the effect of the above said components, the results of preliminary work out of the distributed power plant parameters, obtained at CIAM, named for Baranov, in the activities progress on the engines' schemes of new types, were applied.
Calculations were performed employing the first level model of an aircraft gas turbine engine.
Parametrical studies performed using the developed technique allowed select an optimal degree of double-flowness on specific fuel consumption at course speed, and the degree of pressure increase in the fan. The fan modules' and main engine components dimensionality was redetermined with account for various losses levels at the inlet.
The effect of engine parameters changing on the its mass estimation value was performed with the developed modular technique, based on the idea of impeller machine mass proportionality to compression specific work and corrected specific air consumption. The modular technique coefficients characterizing the weight fraction of the turbojet modules were determined based on estimations obtained for detailed element-by-element mathematical model of mass, in the activities progress on the engines' schemes of new types, at CIAM, named for Baranov.
The obtained results of the parametrical studies make it clear that on deterioration of the factor of total pressure preservation at the inlet by 2%, minimum specific fuel consumption at a cruising mode would be achieved in the distributed power plant with double-flowness reduced by 3%, and the total pressure increase degree in the fan reduced by 0.6%. At the same time specific fuel consumption increases on 6-7 % of percent. The specific fuel consumption herewith is increases by 6-7%.
The power plant weight, without account for the weight of the remote fan modules transmission drive may increase by approximately 4-5 %.
Analysis of the effects associated with the presence of non-uniform total pressure field, resulting in its averaged level reduction at the fan inlet, revealed that the effect of non-uniformity presence itself might be of 15 to 30% of the total effect on the engine thrust. It should be accounted for selection of the distributed power plant shape of the configuration under consideration. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pisarenko V. N. Testability management while an object operation. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 67-75. Foreign-made aircraft (AC) ingress to domestic civil aviation airlines revealed a number of significant challenges, including the testability provision (abbreviated Tst). We will denote testability management hereafter by FTsbl symbol with Tstblt subscript. An ill-considered implementation of foreign-made components in aviation transportation system of Russia without comprehensive accounting for operation and maintenance factors leads to above-level downtime of cost intensive aerotechnics, and upset of calculated value of an aircraft testability. At present, revealing assessments and factors of testability management, gains special topicality and requires comprehensive analysis. Many scientists in Russia, including V.S. Shapkin, N. Gipich, .G. Evdokimov, A. Stepanov, V. Viktorova and abroad, including Douglas, T. Ross, studied testability as the means of equipment failure-free operation provision through its whole life cycle. However, the studies of testability provision while operation are insufficient. The testability management system is being reduced to compliance with the State Standard 27518-87 “Products diagnosis”, i. e. to totality of coordinating activities on management state, as a part of general enterprise management. These activities are not oriented with respect to testability while operation. They are fulfilled without adequate theoretical development on substantiating the required acceptable testability level of object under operation and control action. It does not achieve the desired goal since functional dependencies of testability management, controlled parameters and acceptable limits of testability parameters variation of controlled products are not substantiated theoretically.
The objective of this article consists in studying the possibility of testability management while operation and developing mathematical model of testability management of an object on the example of testability management of aerotechnics.
The article describes the testability as a function of the monitored object under operation. It presents description of testability computation models and algorithms. Based on the theory of optimal processes and Pontryagin's maximum principle the mathematical model of the function test was studied. A mathematical model of an operated object testability management on the example of aerotechnics. This model is based on measuring indices and parameters of operation, processing of the obtained data, analyzing and developing control action on the operated object.
A mathematical model of controlled object under operation testability on the example of aviation technology, based on the measurement of parameters and operating parameters, the processing of this data analysis and generation of control action on the object of exploitation. An approach to testability management of an object under operation was deduced. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Patrikeev S. A. Capabilities of onboard innovation measuring systems while ground and flight tests. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 76-83. The main modern aviation development trends are based on the fact that aircraft qualities are defined not only by carrier characteristics but also by onboard equipment complex capabilities.
High rates of airborne equipment development and creation intrinsic to recent years have come into contradiction with long service life of airframe and engine. Resolution of this conflict supposes abruption of an aircraft common life cycle as an aggregate of an aircraft and its equipment and shift to logically interrelated separate cycles of aircraft and onboard equipment complex development.
The problem discussed herein consists in optimum employment of cost and time resources in aircraft flight and engineering test practice.
Particularly, the flight and engineering tests are described, which essence consists in giving the answer to the question on how the flight task was realized with the accuracy not worse than the specified one.
Parametric expected uncertainty within the problem formulated has some specific distinctions from situations discussed within statistical decision theory.
First of all, the values of the parameters, which define the hypotheses under checking. These parameters, H0 and H1, are not defined (a priori) within the sets of their values Ω0 and Ω1, responsible for the system state (H0 – the system complies with the requirements, H1 – it does not), and are defined in the sense of the system state (“YES” – H0, “NO” – H1).
Secondly, inasmuch as on the assumption of employing information methods for optimization of surveillance planning stage at the interval of an aircraft's ground tests the situation, when the probability in the context of alpha and beta errors is required, is inadmissible. The decision making in this case will turn out to be unobtainable due to the lack of information in the sample of observations.
Substantiated information and cost approach, general formulation and the ways of resolving the problem of surveillance of ground measuring complex means while performing aircraft flight and engineering tests, ensures the effectiveness of flight tests with existing test pattern and requirement for minimum consumption of all kinds of resources.
Proved relationship and interpretation of the results open a possibility of obtaining analytical expression of informational measures necessary within the framework of the problem discussed and formulation of the task for ground measuring system equipment observation plan optimization.
While application of this method, the effectiveness of proposed models was about 9 –15 % of augmentation in terms of economic indicators, and instruments and general structures controllability by 15 – 20 %. Thus, general effectiveness of the proposed model equals to about 20%, which allows for attributing it to qualitatively new flight controllability structures.
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Dong Z. . Analysis of dynamics and motion control of low-orbital space tether system. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 84-91. The paper analyzes the dynamics of a low-orbital space tether system (STS), consisting of a main and a small space vehicles, and a tether connecting them. Under consideration are the stages of deploying, free motion and stabilizing on a low and nearly circular orbit (170-180 km). The tether escapement is performed fr om the main spacecraft by the mechanism operating only on braking action, according to the feedback principle of measuring the tether length and escapement velocity. The tether length after deploying termination is several tens of kilometers.
The study of the STS motion on a low orbit becomes more complicated due to the necessity of considering the atmospheric drag acting on all system elements including the tether. It was demonstrated, that at the end of the STS deploying in a position close to vertical, unavoidable system oscillations relative to vertical occurred, caused by joint affecting of gravitational and aerodynamic forces (aerogradient effect).
The author suggests a nominal deploying program of the low-orbital STS at the position near to vertical. The proposed STS deploying program, compared to the known programs, accounts for the effect of the aerodynamic force acting on the end-bodies and the tether. The program law elaboration is realized by a simplified model with inextensible tether, and written in the orbital moving coordinate system. To verify the effectiveness of the suggested program the STS mathematical model with distributed parameters, wh ere the tether is represented as an aggregate of material points was elaborated and applied. Numerical simulation of the deploying process revealed that the suggested nominal program of the STS deployment allows decrease the amplitude of aerogradient oscillations of tether relative to the vertical by several times.
Simulation of the stages of free motion and stabilization was performed on the model with distributed parameters. When the orbital height of the system's center of mass decreases to a certain value, the low-orbital STS will switch to the stabilization motion in a given range of orbital height (170-180 km). Stabilization of the system orbital motion is realized by a correcting thruster, located on the main spacecraft. Employing the correctiing thruster ensures the flight stabilization of the low-orbital STS in the given range of orbital height. At the stage of STS motion stabilization, restrictions, imposed on the tethers angle deviations from the vertical are executed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Repin A. I., Kashkina T. I. Specifics of application of minimax operations for aircraft lateral movement control. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 92-98. The safety of aircraft landing on approaching the landing strip in difficult weather conditions is associated not only with the need to create light and strong devices, but also, mainly, the search for new principles (methods and tools) for building control systems, since the aircraft landing is the most laborious process and largely unsolved problem to date.
Safety upgrading is achieved by control automating while approaching the landing strip and aircraft landing. It is obvious that the use of standard methods for modeling, analyzing and managing of complex multi-level systems becomes less possible with complexity increasing. In this situation, fuzzy control methods are the most applicable to such complex technological processes as the control of aircraft landing.
Aircraft control systems based on the principles of fuzzy logic, allow increase the course stability of the aircraft. In such situations, energy consumption is reduced and the response time of the system is increased simultaneously. Besides, it is possible to make the system as a whole more stable to the effect of disturbing factors compared to the traditional aircraft automatic control systems.
Practice shows that the operator, in conditions of good meteorological visibility range, satisfactorily lands an aircraft without the help of a program control system and a trajectory control system.
In the case of poor meteorological visibility, with the lack of visual contact with the runway strip, radio technical, optoelectronic and inertial navigation systems are employed for aircraft landing. They are used in the control system as sensors of primary information for the automatic control system (ACS). Such systems are termed course-glissade systems. They determine the position of an aircraft on the course and on the glide path.
But, even with modern control systems provision equipped with computerized hardware and software systems, which functionality is largely determined by software, applied diagnostic models, information processing algorithms, etc., the final decision-making is delegated to the human, which is a consequence of the insufficient effectiveness of diagnostic models, reflecting real ACS and the environment.
Thus, the structure schemes of similar systems in the following stages should include the links with fuzzy transfer function WN(p) instead of links with functions Wo(p ) or Wa(p ) . To this effect, it is rational to implement the of the operator's behavior in such a situation as the basis for the fuzzy controller synthesis. In this situation, namely the methods of fuzzy control are the most applicable to such complex technological processes that will allow reduce by 10 times the duration of the longitudinal and horizontal movements' transients. The pilot in this case operates as a controller for the state of the control system.
Thus, the task consisted in developing models and algorithms for the design of control systems based on the methods of the theory of fuzzy-multiple apparatus.
A program in the C++ programming language was created to reproduce the min and max operations in on-board systems for automatic control of the aircraft lateral movement with applicaiton of fuzzy logic. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kim N. V., Bodunkov N. E., Mikhailov N. A. Automated decision making by the onboard unmanned aerial vehicle system while road traffic monitoring. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 99-108. The article presents the developed method for efficiency increase of the operator, performing traffic surveillance by an unmanned aerial vehicle (UAV) with the built-in computer vision system. Analyzing video information, received via the radio channel in real time mode by the human-controlled point, is associated with errors in decision-making. These errors are stipulated by the vast volume of information, which overburdens the operator, and, as a rule, by the so-called human factor. Productivity of such system can be increased significantly through addition of autonomous road situation estimation system. The UAVs equipped with surveillance systems, such as video cameras, receive images onboard (video sequences), and are able to extract from them the objects of interest: roads and transport means.
Estimation and analysis in this article are ensured by the road incidents consequences severity classification. The work employs the classification consisted of five classes. Each situation class is described by attributes' dictionary, which separates the attribute space into non-crossing areas, corresponding to the selected classes.
In addition, the article describes the developed hierarchical structure of “Description of the Scene Being Surveyed”. This structure relates to the so-called semantic descriptions, is rather universal, and ensures the possibility to describe various road traffic situations.
The article presents the technique for traffic situations classification over the images. It demonstrates the example of the situation classification based on the real image of the road accident. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aglyamutdinova D. B., Sidyakin S. V. An object bounding box refinement algorithm while the tracking process initialization from the uav. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 109-121. The presented article deals with the problem of semi-automatic initialization of the selected object tracking by unmanned averial vehicles (UAVs) or drones. Here, we proposed an algorithm of the position and sizes refining of the boundary rectangle of the tracked object at the start time (on the first frame) based on saliency detection algorithm, which simulates the map of human attention. The advantage of the proposed approach is that it applies the principles used by the human visual system: the color contrast, the main attention is centered on the central objects. The first stage of the proposed approach consists in preliminary image processing (noise removal) by the Gaussian filter and converting the image into the CIE LAB color space. The next stage is segmenting the image into homogeneous areas (superpixels) by simple linear iterative clustering (SLIC) algorithm. Undirected graph is employed as a container for information on segments storage. Based on information from the resulting graph, measures of identity, which assign superpixels to the background or an object, are computed. The resulting saliency measure is computed for each superpixel by optimizing the target cost function, which combines the measures of identity to the background, an the object and the smoothing component. The obtained saliency map of the image superpixels is binarized by the Otsu method. After that, the pixels belonging to the shadow can be determined. At the final stage, the operations of morphological filtering were applied to reduce fragmentation of objects and an algorithm for allocating coherent components, assigning the final dimensions and position of the object of interest for tracking initialization.
The algorithm was used to initialize a number of fast and effective methods of object tracking: DCF_CA, MOSSE_CA, SAMF, DCF, DSST, MOSSE, SRDCF.At the same time, the quality of the tracking was tested on the largest and most complex database of video clips, shot from an unmanned aerial vehicle – UAV 123.
The results of experimental testing allow conclude that the best tracking quality as a result of initialization by the proposed algorithm is achieved by tracking algorithms “SRDCF” and “MOSSE_CA”. In assessing the performance, you can notice that “MOSSE_CA” tracking algorithm is noticeably superior to the other algorithms. In this way, the most suitable algorithm for tracking objects by UAV, along with the proposed initialization algorithm, is “MOSSE_CA”, due to its least sensitivity to the of initial initialization accuracy and fastness among competitors.
The proposed algorithm does not require special hardware and can work in real-time. It is implemented in C ++. The average time required refining the object, occupying 40% of the image size of 256 × 256 pixels, equals 60 milliseconds on the Intel® CoreTM i5-3470 CPU @ 3.20GHz. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abdulin R. R., Zudilin A. S., Obolensky Y. G., Rozhnin N. B., Samsonovich S. L., Stitsenko A. N. Developing of an electromechanical actuator of the higher reliability with redundancy. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 121-131. Popular in recent decades concepts of an “all-electric aircraft” and “more-electric aircraft” assume full or partial replacement of centralized hydraulic systems by centralized electrical systems, and hence application electromechanical and electro-hydrostatic actuators alongside with electrohydraulic steering actuators. In the aircraft of the abovementioned class of the nearest perspective, the electric actuators with hydrostatic transmission are more applicable for the main steering surfaces controll. It is associated with higher indicators of wear resistance and non-failure operation of hydraulic cylinders. Electromechanical actuators application for these purposes is constrained by their insufficient reliability.
The article proposes solutions aimed at increasing the reliability of electromechanical actuators by both element-by-element and structural redundancy. An obligatory element of an electromechanical actuator optimized for weight and size indicators is a mechanical gearbox, which can wedge while operation. Multichannel electromechanical actuators can be constructed by one of the considered schemes, free of gearbox wedging. According to these schemes, each actuator channel must contain a motor shaft locking clutch, employed in case of a channel failure, and while channels serial operation as well. Alternative option are the schemes, requiring employing of clutches splintering the faulty channel off the common load – the steering surface. Such clutches should have reliability indices higher, than those required for an actuator all-in-all. The authors propose to construct them based on low power electromechanical actuators with redundancy.
Based on the comparative analysis results of the schemes options for constructing an electromechanical steering actuator with redundancy, three basic schemes were defined for which the preliminary failure rates were calculated.
The results of calculations allow us to consider the basic schemes of a electromechanical actuator with redundancy as an alternative to electro-hydrostatic steering actuators for a primary flight control system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lupanchuk V. Y. Navigation cartographic methods development for monitoring robotic complexes positioning in surrounding space. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 132-142. The purpose of the study of this scientific article is accuracy improving of monitoring robotic complexes positioning in surrounding space while performing various types of motion.
The subject of the study are methods for joint navigational information processing obtained by on cartographic and instrumental data.
The article analyzes the approach and problems of high-precision positioning of unmanned aerial vehicles and ground-based robotic complexes in the surrounding space.
The initial data of the study are based on formation of local areas of the Earth surface employing cartographic data and instrumental measurements. The article presents the main stages of the methodology for the map high-precision local areas formation by mathematical processing of redundant navigation parameters at the base points.
The methodological approach differs from the known ones by the presence of correlations between the map errors and allows the accuracy increase of navigation parameters determination over the entire area of the local section by 1 m, and by 3 to 5 m at base points.
The studies can find application in various fields:
— when solving problems of high-precision positioning of air and ground robotic complexes in the surrounding space;
— when solving the problems of ensuring and developing the Earth Deformation Control Service within the framework of the Federal System of Seismological Observations, particularly in the highlands of the country;
— rapid creation of a multi-information cartographic basis of various scales with account for correlation dependence of navigation and geophysical information. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ismagilov F. R., Vavilov V. E., Bekuzin V. I., Aiguzina V. V. Structure selection of synchronous motor with permanent magnets and asynchronous start-up. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 143-156. Aerospace industry is in special want of high-efficiency electrical drives (motors), which allow reduce electric energy losses and rise productiveness of equipment. The number of electric drives onboard an aircraft varies from 50 to 220 pieces. With high tech development, the number of electric drives onboard an aircraft will only grow, and insignificant efficiency increase of all electric drives in the aggregate will lead to significant fuel savings. Three-phase induction motors with squirrel-cage rotor are in most common use in aerospace industry as fuel transfer drives. Asynchronous motors with maximum possible energy characteristics possess an efficiency below 80% and a power factor below 0.82. A possible alternative to asynchronous motors are BLCD motors, though their employing as pump drives becomes rather hindered due to cost intensive control system and large weight and size parameters. Another possible alternative to asynchronous motors may be a synchronous motor with permanent incorporated magnets and direct asynchronous start-up. The article is devoted to the analysis of structures of synchronous motors with incorporated permanent magnets and asynchronous start-up, for fuel-transfer pumps drives for the aerospace industry. The analysis was performed by computer simulation in the Ansoft Maxwell software package. The article proves the superiority of such motors over asynchronous motors. The structure of synchronous motor with incorporated permanent magnets and asynchronous start-up, which meet the requirements to fuel transfer drives for aerospace industry, was obtained based on computer simulation. The obtained results can be employed for the design of synchronous motors with permanent incorporated magnets and asynchronous start-up. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov S. B., Kiselev M. A., Moroshkin Y. V., Mukhin A. A., Kharchenko I. A. Electric power supply system with distributed differential high voltage dc-link and modular-scalable architecture for all-electric aircraft. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 157-166. The promising concept of all-electric aircraft free from pneumo- and hydro actua-tors for flight control and stabilizing rotation frequency of main starter-generators supposes significant rise of power supply capacity up to 1.5 MW and more. To ensure high reliability indices and quality of supplied electric energy, the parallel con-nection of supply channels of onboard electric power system should be provided, as well as reversible (bidirectional) interconnection with stand-by low-voltage batteries.
To realize the concept of all-electric aircraft, the article suggests application of the so-called differential higher voltage DC-link with frame grounded averaged-potential (“zero”) wire.
Apart from the well-known benefits of the high DC voltage distribution subsystems, suggested high voltage DC-link has specific benefits, which allow substantiate particular requirements to the power supply systems for domestic all-electric aircraft.
As an example, the article presents the power circuit of the electric power supply combined channel with high voltage DC-link and standby battery based uninterruptible source for combined electric power systems with modular-scalable architecture. It also describes this channels operation. The reviewed structure of a single-phase power supply channel with high voltage DC-link may be recommended as an interrelated group of unified modules of switched mode converters applicable for synthesis of combined power supply systems with modular-scalable architecture and enhanced power supply capacity, and for all-electric aircraft power supply systems in particular.
The article suggest also the combined power supply system with distributed higher voltage DC-link and modular-scalable architecture for all-electric aircraft. Schematic and algorithmic solutions for three types of multifunctional switched mode converters, encompassing all specter of necessary conversions in onboard systems are considered. These solutions allow realize power supply systems with modular-scalable architecture for all-electric aircraft with account for import substitution of power electronics product range. The article presents the example of a simplified combined power supply system with differential higher voltage DC-link of hypothetical all-electric aircraft with four cruise engines and four main starter-generators. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abramovich B. N., Sychev Y. A., Kuznetsov P. A. Electromecanical complex with high-frequency induction drive for gas-turbine engine. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 167-179. The main issue of this article is modeling and reviewing of the possibilities of high-speed induction motors to modernize conventional and newly developed technical solutions.
The performed analysis reveals that by the year 2050 electrical energy production and consumption will practically double relative to 2015. Electric drive is one of its key consumers, and induction motors as the main motors. In this regard, presently the issue of meeting the rapidly developing industry requirements for developing highly effective reliable models capable of operating under conditions of drastically changing load arises.
The prospective arrangement to be modernized with such electric drive is a gearbox of a gas turbine engine. Difficultly controlled and tightly coupled with gearing-system, the pumps can be substituted by their lightweight, small-sized analogs in the form of electric drives. The authors offer two possible structures of modernization of various degree of complexity.
The induction motor modeling is complicated by computing parameters of its equivalent scheme. The article presents the review of the key values hard to calculate, and simplifications description, which were assumed while those parameters computing. The induction squirrel-cage motor with two rotor windings was selected as the basic model.
Two models for studying characteristics of high-speed motors were developed with MATLAB-Simulink. The first model simulates the motor with frequency regulator, and the second one is finished electrically driven gearbox of gas turbine engine aggregates. The problems of harmonic components generation by frequency converters are considered as well.
High frequency motors simulation results were compared to series-produced analog. They demonstrate the superiority of the new models compared to conventional, such as less jitter of the velocity curve, reduced inrush current, faster transients and increased torque. Comparison of variable-frequency control technique advantages with series-produced analogs was performed in the final part. The wider capabilities of the enhanced frequency range are demonstrated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsov D. A., Poletaev A. S. Multiphase pulse-width modulators for devices with a multichannel principle of electric power conversion. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 180-189. The energy path separation of switched mode electric energy converters into several channels with power switches control in different phases is a promising method for increasing the energy efficiency, reliability, and manufacturability of these devices. Selection of pulse-width modulator control mode for power converting cells while synthesizing the structure of a switched mode power converter with stabilized output voltage is of fundamental importance. Current mode has a number of significant advantages over Voltage mode. They are as follows: – better regulation dynamics; – possibility of simpler overcurrent protection ensuring; – automatic uniform distribution of currents between power converting cells. The main disadvantage of current mode is the possibility of subharmonic oscillations occurrence in continuous current mode. To ensure subharmonic stability, slope-compensation, or the duty cycle limited within the range of 0–0.5 are applied. The article proposes three circuit solutions for multiphase basic frequency generator with a duty cycle equal to 0.5 and uniform time shift between phases for multiphase pulse-width modulators in Current mode. A generator with a number of phases of N, defined as N = 2k, where k is a natural number, can be built employing T-flip-flops. The N-phase generator circuit, requires N–1 triggers. The disadvantage of the scheme is the limited choice of the possible number of phases. Its advantages consist in realization simplicity and automatic restoration after a failure caused by external jamming. A generator with any integer number of phases N – k can be realized employing a shift register. N-phase generator circuit requires an N bits register. The circuit is also insensitive to failures. A generator with an even number of phases N – 2k can also be implemented employing a shift register. To obtain N phases according to this principle l – N/2 register bits are sufficient. The drawback of the last proposed scheme is inability of its automatic recover after a failure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Egorova Y. B., Davydenko L. V., Chibisova E. V., Shmyrova A. V. The effect of chemical composition and heat treatment on mechanical properties of forgings from a pseudo-ß-titanium alloy. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 190-201. The article presents the results of statistical studies of mechanical properties of the deformed semi-finished products from Ti-10V-2Fe-3Al titanium alloy based on analysis of literature, experimental and commercial data, by the “Stadia 7” software package. The effect of reheat temperature for quenching Th, as well as ageing temperature Tag on mechanical properties was evaluated by method of regressive analysis of the published tе data. Equations for computing polymorphic transformation temperature beta-transus temperature βtr and the quantity of primary α-phase, formed while quenching process on the temperatures interval from 700 °C to βtr were obtained:
βtr = 890 + 22,3Al - 13,9V - 8,0Fe,
nα = (0,3 ± 0,02)·( βtr-Тh), %
.
1608 ingots and die forgings, manufactured by the industrial technology in 2007-2016 were also the subjects of research. All forgings were subjected to thermal treatment, consisted of quenching (763-798°C for three hours followed by water cooling) and ageing (500-515°C for 8 hours followed by air cooling).
The following factors were selected for statistical analysis: alloying elements’ and impurities’ content, beta-transus temperature, alloy structural equivalents in aluminum and molybdenum, hardening temperature Th and the aging temperature Tag, the mechanical properties (offset yield strength σ0,2, tensile strength σв, elongation δ , reduction of area ψ , fracture toughness K1C). Primary statistical processing and correlation-regression analysis were performed.
Correlations between mechanical properties with deviations of the brand composition and heat treatment modes were established. At the first stage, pairwise correlations between the investigated factors were analyzed. The results of the analysis revealed that each element separately either does not affect, or affects weakly the level of mechanical properties of forgings, which is most likely stipulated by small intervals of their change. The joint action of the elements, which was evaluated by and , appeared to be more significant, the coefficient of multiple correlation was R=0.3-0.5, the fraction of the of the properties variation was γ ≈10-25%. Coefficients of multiple property correlation with quenching temperature and aging temperature were equal to R = 0,3-0,6 depending on the year of production. The joint effect on theproperties of all four factors (, ,Тh, Тag) is evaluated by the coefficients R = 0,35-0,67, γ ≈ 12-45 %. The rest of the variation is stipulated by factors that could not be determined based on the data studied. The generalized regression dependence of the tensile strength of Ti-10-2-3 forgings on the chemical composition and heat treatment modes is:
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Voronin S. V., Chaplygin K. K. A technique for determining aluminum alloy grains crystallographic orientation in polarized light. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 202-208. The assumption on the possibility of employing interference pattern of aluminum alloys surface in polarized light for determining crystallographic orientation of separate grains was put forward. This assumption was tested on the example of aluminum alloy AD1. Optimum modes of electrolytic etching of AD1 alloy, under which the grains' boundaries were sharply defined, and necessary interference pattern of the grained structure was attained, were defined. Electrolytic etching was being performed in a 40% solution of hydrofluoric acid, boric acid and distilled water at 1.7-1.9 A, 100-110 V, and etching time duration of two minutes. It was established that the interference pattern of the sample surface changes with prolonged exposure in the open air. This was due to the oxide film's growth process. Employing literature data on elasticity modulus of aluminum mono crystals depending on crystallographic direction, the article defines the relationship between the grain elasticity modulus and its crystallographic orientation over three directions by the scanning probe microscopy method using NanoScan-3D device. Scanning of the studied section with a size of 128 х 128 µ m was carried out at a speed of 30 µ m/sec.During the scanning process, the signal from the indentation sensor was recorded and processed, resulting in a surface profile map (Zopt). Modulus of elasticity of separate grains was determined by the method of removing the curves of the indenter's supply to the surface of the sample for each grain in the section under study.
While comparing the interference pattern with the distribution of modulus values, it was found that the grains of blue color corresponded to minimum values of modulus of elasticity from 46 to 55 GPa. Maximum values of modulus of elasticity were in the range from 69 to 78 GPa, and corresponded to yellow grains. It was established also that pale orange grains correspond to modulus of elasticity from 55 to 64 GPa. As a result, the assumption was made that the blue grains have a crystallographic direction [100], since they have minimum modulus of elasticity in the array of obtained values. Yellow grains have a crystallographic orientation [111] and maximum modulus of elasticity from the values obtained. Pale orange grains occupied an intermediate position by value of modulus of elasticity, so it was assumed that their crystallographic direction corresponds to [110].
The developed technique is characterized by simplicity, low energy intensity, and less time consuming, in contrast to the methods traditionally used for this purpose. This technique can also be employed to determine the crystallographic orientation of individual grains of other aluminum alloys. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishin D. V. Development of effective forms of production process stuffing in aircraft building industry. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 209-219. The aviation industry is one of the most high-tech industries not only in the product design and development, but also in the production process posing high requirements on personnel qualifications. The system of qualifications assessment and certification in the aviation industry helps to solve the issue of staffing of the production process due to:
The systems of professional certification in Europe and the United States has been functioning since the 1980s. In 2007 a large-scale activities on creation of National system of qualification started in Russia under the auspices of the RSPP. Since 2014, this work was being performed on the ground of the National Council on Professional Qualification under the President of the Russian Federation. The Council for professional qualifications in the field of aviation was established in 2016, it included representatives of major employers and their associations, public authorities and educational institutions.
At the first meeting of the Council, it was decided to consider the possibilities of employing and adaptation of the project sectoral qualifications frameworks in mechanical engineering for aircraft industry. For this purpose there are all preconditions, since the enterprises need the skilled workers in the first place, and it was for them that the Sectorial Council on Machine Building develops qualification requirements.
Based on Federal law No. 238-FZ “On independent qualification assessment”, 108 organizations, getting the status of centers of assessment of qualifications were selected, in which more than five thousand people have already confirmed their skills.
Currently CTCS in the field of aviation has not been not established, however the need for its creating is urgent. Though MAI cannot act as the CSC organizer, it is likely expedient to enlist the services of the MAI teaching staff to its activities In particular, the administrative tasks of CTCS can be transferred to MAI, which has extensive experience of performing similar procedures: admission company, examinations, etc. The proposed system will help the industry economically, as well as strengthen the ties between the labor market and educational sphere. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Manvelidze A. B. Defining tнe demand for passenger airplanes in conditions of market saturation ву foreign-made aircraft. Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 220-232. The problem of Russian air companies' transition from employing foreign-made passenger aircraft to domestic ones is under consideration. The article analyzes the status of passenger aircraft being under operation or being ordered for the future. It also defines the aircraft ownership i.e. financial leasing, or operational leasing or airline's property. Мost attention is payed to the study of an aircraft operational leasing, since regulation of aircraft park being in temporary service will allow release market niches for domestic built aircraft.
The article presents a methodical approach, allowing assess variants of freight capacities volume formation based on statistics monitoring to implement new airplanes of domestic manufacturing.
Analysis of the rules of statistical accounting applied by US airlines led to the idea of the above saic proposed methodology. The Bureau of Transportation Statistics (BTS) of the USA publishes monthly the detailed airlines reports on distribution of aircraft types by airlines, reflecting distance factors, the number of planned and actually performed flights, passenger traffic, cargo and mail, available seat-miles, passenger-miles, ton-miles, flight hours and aviation fuel consumption. Based on the detailed data, brief reports on aircraft employing are being compiled and can be sent to aviation organizations, such as ICAO. The detailed presentation of information allows perform studies on modernization of aircraft fleet under operation adequately and without extra resources.
The air transport of Russian Federation publishes brief statistical forms on aircraft availability and usage (32 civil aviation and 33 civil aviation). To obtain detailed data on performed air service by airplanes of airlines the data on full schedules (SRS Analyser) and passenger transportation along the routes are being integrated.
The calculations simulating the workout resources of an aircraft in use are performed using the network modelled in such a way. In the longer run, the demand for airlifts rises, the aircraft in service drops out, and a niche of free seat-volumes for new aircraft implementation appears.
The source of information is the Transport Clearing House statistical database on aircraft fleet at disposal and employing this fleet by airlines and industry at large, transportation between pairs of cities, as well as international databases. The Flight Global database is used to analyze the state of passenger airplanes' park. It gives a comprehensive idea of air transporters' airplanes under operation and aircraft building industry perspectives. The airplane schedule and freight capacity were accepted according to SRS Analyser database. In calculation for perspective, the United Aircraft Corporation plans on aircraft building up to 2037 were accounted for. The market niche formation of new aircraft implementation is affected mainly by the demand on passenger aircraft seats as a whole and by segments; terms of passenger airplane disposal; signed contracts of airlines on the delivery of foreign-made aircraft; delivery plans of domestic manufactured aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Efimova N. S., Volenko A. K., Kanashova Y. G. High-tech production managing with account for requirements of economic security (on the example of aircraft building). Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 233-242. Presently it is necessary to develop highly effective assessment of high-tech enterprises economic security level as each aircraft building enterprise needs integrated self-concept of its production-commercial and financial-economic activities.
The main objective of assessment of the level of production activity economic security is assessment of risks on integrated system of indicators accounting for specific branch features at the enterprises of high-tech industries. The authors recommend employ the hi-tech enterprises' risks assessment based on a qualitative or interval method. Internal self-concept of state of production of aeronautical engineering development, and assessment of production development dynamics of the enterprise should be the main task of high-tech production monitoring.
The internal self-assessment of a production condition of creation of the aircraft equipment and assessment of dynamics of development of production of the enterprise have to be the main objective of monitoring of hi-tech enterprise. For this purpose, it is necessary to employ the technique, which would describe the main approaches and basic self-concept procedures for the risks of production departments of high-tech enterprises.
The article considered and developed managing system for high-tech production with account for economic security requirements, which will allow ensuring the raise of high-tech products competitiveness.It suggests assessment indicators for probability category of economic security factors coming-in, risks register, and risks map in high-tech branches of the industry.
Developing the system of economic security of production activity in aircraft building will allow forecast the aftermath of internal and external hazards on both production processes, and high-tech enterprises' activities at large. Implementation of the above said procedures at the aircraft building enterprises will allow ensure the necessary level of economic security, as well as optimize production processes at the enterprises of high-tech industry branches. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozlov A. E. Export potential of an aircraft building enterprise: development trends and predictive modeling (on the example of Progress Arsenyev Aviation Company). Aerospace MAI Journal, 2018, vol. 25, no 1, pp. 243-255. Enterprises are constantly facing competition, both at domestic and foreign market. The competition promotes the development of export, but the risks associated with an unsatisfactory estimation of activity of an enterprise and improper planning may inflict damage to the company.
To consider the issue of products export one can employ the following method of export potential assessment to promote products and services at foreign markets:
Since the Holding Company “Helicopters of Russia” occupies the leading positions in military-industrial complex development, the article is devoted to the study of export potential of one of its enterprises, namely, Arseniev aircraft company “Progress”, which, plans to export military equipment in 2017.
To avoid the above said risks, the company was proposed to employ the model developed by the author for export potential predicting, based of complex evaluation of enterprises. The model is based on evaluation of the basic technical and economic, accounting and financial indicators, as well as indicators of the enterprise's management and its scientific and technical potential. It includes also statistics of qualitative and quantitative structure of personnel, gender and age structure, work experience of engineering personnel, managers, fellow laborers, workers, as well as information on the research work and capabilities of research projects performing.
Summarizing the results on the above listed factors, a model of the multiple regression describing the dependence of the export potential of human resources was built, which was subsequently automated with a software application.
As the result, the program was:
– effective, since the payback period was 45 days at a low annual economic effect;
– universal, since applying this tool is possible for other enterprises (not only the aircraft industry);
– easy-to-use, since the users need only necessary information on the enterprise dynamics, and, according to the theory of mathematical modeling and regression analysis, the more data will be used, the higher the model adequacy and forecast accuracy will be. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abashev V. M., Demidov A. S., Eremkin I. V., Kiktev S. I., Khomovskii Y. N. Temperature stresses in a cylindrical shell of carbon fibers and the contact problem of heat transfer. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 7-13. Cylindrical shells are the most common structural elements of rocket engines. When loading by the temperature gradient in radial direction radial temperature stresses occur in them. Such stresses in carbon-carbon shells can be rather dangerous notwithstanding that they are much smaller than the circumferential and axial ones. Moreover, they substantially depend on the thermal conductivity of the carbon fiber material and the shell structure. The article suggests the equation for the structural thermal conductivity (contact thermal exchange) evaluation of a cylindrical shell in radial direction. When calculating with the equation the carbon fibers' roughness was not accounted for due to the presence of pre-preg matrix, and the shell was divided conditionally through-the-thickness into several layers. The contact forces acting on the fibers were determined based on a primary evaluation of the temperature stresses. The results of the shells' made of carbon fibers calculations with a diameter of 0.02, 0.05, 0.2, 0.5, and 1 mm are presented in the form of tables and graphical dependencies. It is shown, that the elasticity modulus of the first genus of carbon fibers' surface layers can be accounted for in the calculations. It was revealed, that in shells with internal warming-up the specific pressures at the areas of contact spots of the adjoining fibers could reach several tens of kilograms per square millimeter. There is a risk of the carbon fibers structure stratification in the shells with the external warming-up. Thus, we recommend conduct tensile or bending tests with small-sized samples, cut from the shell in radial direction. Tests of such samples should be carried out according to the methodological instructions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bezuevskii A. V., Ishmuratov F. Z. Quasi-static deformations effect on aeroelasticity characteristics of an aircraft with high aspect ratio wing. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. . One of the ways to increase the aerodynamic quality of modern and prospective aircraft consists in wing aspect ratio increasing. Such increasing leads to the occurrence of various new aspects of the structure loading, strength and aeroelasticity. One of these aspects is increasing of the wing flexibility, and as a consequence, possible in-flight structures deformations effect on aeroelasticity characteristics. The paper presents a review of publications on the deformation effect on various aeroelasticity characteristics. It suggests and substantiates a computational method for studying the effect of quasi-static deformations of the wing on static and dynamic aeroelasticity of an aircraft. This method is based on automated generation of a set of aircraft computational models using the Ritz polynomial method. The paper presents the examples of a wing in-flight deformations effect on characteristics of static elasticity, frequency and shape of elastic vibrations, and flutter characteristics. The results of the developed method application for aircraft of various configuration allowed establishing the main regularities of the effect of structure's deformation on aeroelasticity characteristics. The effect of in-flight deformations on the characteristics of static aeroelasticity and load is determined by: 1) effective wing span decrease; 2) aerodynamic forces direction changing; 3) increase of the effective dihedral angle. Characteristics of longitudinal motion can reduce by 5-6%, while characteristics of lateral motion can increase or decrease by 5-15%. The dynamic aeroelasticity characteristics change is determined mainly by the increase in the interaction of torsional oscillations of a wing with bending vibrations in the chord plane. For the unmanned aerial vehicles with a wing of extremely high aspect ratio, this effect can lead to a significant decrease in flutter speed (up to 30-50%). For modern airliners, the decrease in flutter speed due to the in-flight deformation does not exceed a few percent and lies within the accuracy of numerical methods. An important feature of the method is its integration into a multidisciplinary design complex ARGON, validated while solving aeroelasticity problems in many practical applications. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Marakhtanov M. K., Pil'nikov A. V. On solar electric propulsion system application possibility for low-orbit small spacecraft. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 26-39. A comprehensive material on operation of spacecraft with solar electric propulsion systems is accumulated by now. The latter are designed for spacecraft correction on both geostationary and circular low earth orbits.
At the same time, there is a tendency to developing of small spacecraft of various purposes, such as scientific, communication, Earth remote probing, navigation, hydro-meteorological etc. operating on low circular orbits with the height within the rage of 180–280 km. Such spacecraft are relatively cheap and possess the mass of 10 to 500 kg. However, such indicator as minimum orbit height, its relationship with the spacecraft weight and size, as well as parameters of its engine unit remain undetermined. System analysis and experimental data on spacecraft with solar electric propulsion systems, operating at the height of 140–280 km are practically inaccessible.
The paper considers the problem of small spacecraft transition fr om a higher circular orbit to a lower one. As far as the Earth atmosphere gradually transfers to vacuum, the aerodynamic drag force grows while a spacecraft descent. We suggest surmounting this force through the electric jet engine thrust power. It is obvious that while the spacecraft descent the aerodynamic drag grows, and such parameters as thrust power and electric jet engine power should be increased continuously. At large the problem becomes dynamical. Besides, the main cause of the orbit height limiting will be the drag force of the solar battery. Thus, the minimum orbit height hmin below which the spacecraft, equipped with the solar electric jet engine cannot exist, is limited by the spacecraft drag force due to the solar battery. At the lower altitude the battery's drag force will be greater than the electric rocket engine thrust force.
For the spacecraft motion analysis, we assumed that the solar battery takes the shape of an autonomous panel with rotation angle control to the sun radiation direction. The power flux density or the solar radiation at the Earth orbit is Q = 1400 W/m2 (solar constant). The efficiency of photoelectric transducers based on a three-stage gallium arsenide (GaAs) equals to ηSB= 0.22. The solar battery specific power is α = 308 W/m2. If the solar battery plane is oriented normally to the orbital movement velocity vector the drag factor equals to CSB = 2.15, and if it is oriented along this vector it equals CSB = 0.15.
If an ion thruster is used as an electric jet engine its specific impulse is assumed as ΙSP = 4500 s, and its efficiency equals to ηT= 0.7. In case of plasma engine of the SPT type ISP = 1700 s and ηT= 0.55 correspondingly.
The lower limits of the orbit altitude hmin = 200 for the solar electric jet system with the ion engine, and hmin = 180 km with plasma engine of the SPT type were established by the results of the performed analysis. The upper lim it of the altitudes descending from which requires continuous build-up of the electric jet system solar battery area to overcome the atmospheric aerodynamic drag is the altitude of hmax = 260 km.
The paper demonstrates that for a spacecraft continuous exploitation at the latitude of 180–260 km application of solar electric jet engine and atmospheric gas as a working agent is possible. Application of high- frequency ion engine of 4.4–5 kW is expedient for the propulsion installation such kind. With the specified power and solar battery weight, the weight of electric jet propulsion installation will be no less than 90–100 kg, and the total minimum weight of the spacecraft will be no less than 500–600 kg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuz'michev V. S., Tkachenko A. Y., Filinov E. P. Effect of turbojet engine dimensionality on optimal working process parameters selection. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 40-45. With turbojet engine thrust reduction, its small size begins affecting the effectiveness on its elements. Lower airflow rate results in blades size decrease and relative radial clearance increase. It affects the efficiency of axial turbo-machines. Due to this, radial and centrifugal turbo-machines become more effective at small thrust values. The main goal of this study consists in determining the most effective structural scheme of a turbojet engine for the thrust range from 0.1 kN to 100 kN. The problem was solved by performing the engine multi-criteria optimization employing ASTRA CAD, developed in Samara National Research University. The total weight of a power plant and fuel, as well as specific fuel consumption were selected as performance criteria. The optimized variables are the gas temperature prior to the turbine, and total pressure ratio. According to the optimization results the following inferences were drawn. With optimization of the engines with the thrust, lower than 25 kN, corrections on their small-size should be accounted for. With the engine thrust decrease, the optimal parameters of the working process are decreasing either, and the regions of compromises are contracting. The axial compressor is optimal for the thrust of 7 kN and higher, and with thrust decrease up to 1.3 kN, compressor of axial-centrifugal type becomes more appropriate. The axial turbine is effective up to 0.7 kN thrust value, and radial turbine is effective for small engines with lower thrust. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezrokhi Y. A., Khoreva E. A., Kizeev I. S. Determining the thrust of an aircraft gas turbine engine with flows mixing under condition of non-uniformity of total pressure at the engine inlet. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 46-51. The article deals with the flight thrust determining method of a bypass engine with flows mixing in the presence of a non-uniform total pressure field at its inlet. The non-uniformity impact is taken into account for both air consumption due conventionally averaged total pressure at the inlet, and the specific thrust due to the overall pressure level reduction along the engine passage, and, respectively, the available differential pressure in the jet nozzle. Earlier, the authors developed and patented the engine thrust determining method allowing evaluate its thrust while in flight under condition of the uniform flow at its inlet according to the measured operating conditions and external environment parameters. The presented work extends this simplified engineering method to the real case of a non-uniform total pressure field at the engine inlet. Moreover, it employs corrected values of the total pressure along the engine passage to compute the thrust. Thus obtained, the value of the flight thrust can be used in both automated control system for its possible in-flight correction, such as partial or full flight thrust value restoration, and the complex engine diagnostics system to evaluate its deterioration rate and deterioration in performance of its separate parts and elements. Calculated evaluations performed according the developed method with account for typical input total pressure non-uniformity revealed that the expected thrust fall will be of 8.9%, with about 8% herewith due to the air consumption reduction, and the rest is due to specific thrust decrease. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Belyaev I. V., Valiev A. V., Moshkov P. A., Ostrikov N. N. Studying the PTERO-G0 unmanned flying vehicles acoustic characteristics in AK-2 unechoic chamber. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 52-62. Recently, more and more attention is paid to the problem of ensuring unmanned flying vehicles (UAV's) invisibility in various frequency ranges due to the wide application of the systems with small sized UAVs for solving special assignment tasks. To ensure the UAV's invisibility in the audible frequency range at the specified distance from the observer in conditions of known terrain of application, the qualitative data on the UAV acoustic characteristics is required. The experimental study of the small sized UAV's “Ptero-G0” acoustic characteristics was performed within the framework of the presented work. The UAV's power plant consisted of a single-cylinder gasoline internal combustion engine (ICE) and a small sized two-blade propeller with the fixed pitch. The acoustic tests were performed in TsAGI unechoic chamber AK-2. The following main results were obtained as a result of experimental researches.
Within the framework of the subject's of UAV acoustics development, the authors are planning to proceed this work in the following main trends.
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Kruglov K. I. Numerical calculation of temperature distribution in power sypply unit of a radio frequency ion thruster. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 63-69. Thermal flows emitted by power sypply unit (PSU) components lead to their heating, which, in its turn, may lead to changes of their operating characteristics up to their failure. Thus, the temperatures of these components should be maintained within the ranges ensuring maintenance of their operating characteristics. For this purpose a preliminary simulation of thermal processes in the PSU housing was performed.
The article presents a model for temperature distribution calculation in separate components of a radio frequency ion thruster's structure. These calculations were performed using ANSYS bundled software.
Due to the negligible effect of thermal flows from the thruster unit on the thermal state of PSU, thermal simulations of the thruster unit and the PSU were performed separately. The aluminum thermostatically controlled mounting flange, located above the gas-discharge chamber presents the boundary.
All PSU's structural elements in the computer model are simulated as simple geometric forms, such as cylinders or parallelepipeds with appropriate geometrical dimensions.
The total heat emission in the PSU unit from all its constituting elements is taken equal to 66.4 W. This value corresponds to the operating mode of a low-power radio frequency ion thruster.
To intensify maximally the heat removal by radiation, the emissivity factor of 0.9 was attributed to all external surfaces of the PSU unit components.
To maximize radiant heat removal, the outer surfaces of elements of PSU were modeled with the emissivity of 0.9. To increase the conductive heat exchange, a partial PSU components' potting (gersil) was performed.
The calculation used the real thermal contact between adjacent surfaces with corresponding values of thermal junction resistance. A series of calculations was conducted for various the compound's thermal resistance values from 1.2 to 2.7 W/(m·K).
The figure below shows the dependence of the temperature of the most heated component of the structure under various thermal conductivity coefficients of the compound.
The requirements for the thermal conductivity of the compound for filling the PSU's PCBs were determined.
When using materials with thermal conductivity exceeding 1.7 W/(m·K), it is possible to ensure the permissible temperature of electronic components at a temperature of the mounting flange reaching 50°C.
The developed physico-mathematical model can be employed at the stage of the ion thruster preliminary designing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chubov P. N., Saevets P. A., Rumyantsev А. V. Thermal calculation of the SPT-50 stationary plasma thruster. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 70-79. Development of the SPT-50 thermal model, thermal calculations and study of the model sensitivity to changes and to various combinations of internal and external heat exchange parameters was carried out with account for the requirements of the Thermica software applications package (SAP) based on employing of isothermal elements method. The thermal model under development consists of 130 elements. The radiation couplings for the SPT-50 anode unit's thermal model were computed employing Thermica V4 SAP. To obtain the information on the thruster thermal state during thermal vacuum tests (TVT) it was equipped with temperature detectors, installed on the thruster in places with enough access to the surfaces for contact welding, glue and other ways of mounting. The SPT's thermal balance thermal vacuum and thermal cycling tests were performed. The thermal model correction with the testing results was realized by thermal calculations employing the developed thermal model. The calculations did not account for convective heat exchange (imitation of vacuum). The ambient temperature was set the same as the during testing, and SPT's optical and heat emission properties were set according to the operating mode during TVT. The developed thruster thermal model, updated by testing results tests, allows analyze thermal processes inside the thruster in the places where installation of thermocouples is impossible. After the SPT-50 thermal model correction one can define the critical design elements, thermally affected by the thruster. Based on the thermal calculation results, the element of wire with critical temperature level has been defined, and this value approached maximum temperature value of 220°C. To decrease the wire temperature, we increase the wire core section area to enhance the heat sink from the wires critical element. The calculations revealed that the temperature of the SPT's critical elements does not exceed maximum admissible working temperature. It confirms correctness of the approaches to selection of thermal design and parameters of the thermal regulation system of the SPT-50 anode unit. The presented thermal model of the SPT-50 anode unit can be employed for developing other options of thermal and mounting interfaces for other discharge and magnetic thruster operating parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ermoshkin Y. M., Galaiko V. N., Kim V. P., Kochev Y. V., Merkur'ev D. V., Ostapushenko A. A., Popov G. A., Smirnov P. G., Shilov E. A., Yakimov E. N. Specifics of transients in the discharge circuit during the SPT-140D plasma engine starting. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 80-88. The article presents the results of transients' in discharge circuit studies during SPT-140D plasma thruster starting while its operation together with power processing unit (PPU). SPT-140D is an electric thruster developed by the Design Bureau “Fakel”. This thruster was running on Xenon with the discharge voltage of 300 V and power of 4.5 kW, ensuring reactive thrust 280-290 mN and 1750 s specific impulse of thrust. At present, this thruster is ready for flight application for spacecraft motion control. The PPU unit was developed and manufactured by the Scientific and Production Center “Polus”. Since the main discharge is one of the powerful PPU loads, the main attention was payed to the study of transients in the power supply circuit of the main discharge. The obtained data was used for the development of imitation model of the named transients and electric imitator of the thruster for off-line PPU optimization and testing without the thruster. In addition, the information on the specifics of the thruster operation was obtained. The most interesting among them are the following:
Thus, the employed methodology of the study is useful also for conducting physical research of the processes in the thruster.
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Shorr B. F., Melnikova G. V., Serebryakov N. N., Shadrin D. V., Bortnikov A. D. Calculation and experimental evaluation of damper efficiency for decreasing vibratory stresses in turbine rotor blades. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 89-99. The subjects for study are dampers of various masses installed under the platforms of turbine blades.
The research issue is prevention of turbine blades failures caused by higher level of variable stresses.
The goal of the work consists in experimental and computational definition of effectiveness of shock-absorbing insertions' masses (3.3 g, 4.7 g and 5.8 g) for variable stresses reduction in the full-size turbine wheel.
The methodology of the work includes two trends: computation and experimental. The computation trend is based on modeling the damper using MSC.Nastran contact elements and estimating the reduction of vibratory stresses, by integrating the equation of motion in the time-domain employing the standard non-linear integration procedure by the Newmark method. The effect of the insertion on vibration frequencies of the blade was also studied. The experimental trend is based on a comparative analysis of the amplitudes of vibratory stresses in the blades both with installed damper and without them. Tests are performed on the CIAM bench test (manufacturer is Test Devices company). The turbine wheel is assembled for testing in a special way: one sector of the wheel is damper free, and the rest three sectors were equipped with dampers of various masses. The blades were prepared with strain gages, and in each sector the blades with maximum response to external excitation from the air supplied to the test chamber were selected. Tests were carried out for an unheated wheel.
The calculations revealed that the most effective reduction of vibratory stresses in the blade occurs when the holddown pressure of the damper to the bottom surface of the blade platform are 200–800 N. Such forces for damper mass of 3.3 g were caused by centrifugal forces at rotational speeds of the wheel in the range 35–70 % of the maximum rotational speed; this range is 29–58% for the damper of 4.7 g, and for the damper of 5.8 g, it is 26–51%. The affect of dampers weighing 4.7 g and 5.8 g is ineffective, starting, respectively, from 90% and 82% of the maximum rotational speed. According to calculations, the damper with mass of 3.3 g allows reduce the vibratory stresses by 22% at a resonant mode at the 87% of maximal rotational speed.
The tests revealed that, in comparison with damper and without damper, the blade frequency with shock absorber of 3.3 g increased by also 16%, and the oscillations' amplitude decreased by 25%. This correlates satisfactorily with the computation data.
Conclusions were drawn that the calculated and experimental results in these studies showed, in general, a satisfactory agreement with respect to both the reduction of vibratory stresses and the change in the resonant frequency when a damper was installed. Some discrepancy between the calculated and experimental data on the effect on the vibratory stresses of “heavy” inserts of 4.7 g and 5.8 g may occur due to the assumptions in calculations, as well as to the errors in the experiment and processing of the test results. To evaluate the effect of the amplitudes of vibratory stresses in the blade without damper, stiffness and mass of the damper, as well as friction coefficients on the effectiveness of the damper to reduce the vibratory stresses in the blade, additional experimental and calculated studies are required. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bogdanov V. I. Research on realization of pulsating working processes in jet engines. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 100-109. The article presents the results of the study in elaboration of scientific discovery No 314 “Phenomenon of the abnormal high growth of thrust in the ejector process with pulsating active stream” performed in MAI. The possibility of pulsating jet impulse increase through ejectorless addition of gas mass both from the external atmospheric environment and used up gas was shown experimentally. It increases the meaningfulness of the discovery. The physics of the process of the used up gas mass in pulsating stream is based the well-known phenomenon of wave interaction of cyclic masses with various velocities of front and tail parts.
Calculating and experimental studies substantiated the capability of creating a nozzle with the spherical resonator-thrust amplifier for air-breathing jet engine with stationary fuel combustion. The mechanism of gas masses adding in oscillating process is shown. The thrust amplification at certain gas-dynamic and geometrical relationships herewith can make 1.5 and more.
Carrying out of experimental studies on a vacuum bench (imitation of space conditions) has confirmed effective exhaust gas mass addition that opens new capabilities for increasing the thrust efficiency of space jet engines. According the test results, the constructive recommendations on the improvement of working process are given.
The results of computation and design working out of implementation of the obtained effects in the nozzle with the resonator of an optimum configuration for conventional air-breathing jet engine without its mass and dimensions characteristics derating present a great practical interest. Conditions and recommendations on calculation are given.
Possible perspective trends of further studies on implementation of the obtained effects of thrust increase at the expense of exhaust gas mass addition in liquid-propellant rocket engine and solid-propellant rocket engine with spin detonation fuel combustion, as well as in a gas turbine engine are determined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sha M. ., Agul'nik A. В., Yakovlev A. A. The effect of the computational mesh while mathematical modeling of the inflow of a subsonic flow onto the profile of a perspective blade with a deflectable trailing edge in a three-dimensional setup. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 110-121. In the last decade, much attention has been paid to the studies conducted in the interests of mathematical modeling methods developing in 3D setup. It requires a detailed study of various computational meshes constructing methods and their effect on the obtained results.
The problem of the aerodynamic characteristics computation of the of a perspective blade with deflectable trailing edge profile is important for both the development of wind turbine blades, compressor design for advanced gas turbine engines, and aircraft structures.
The effect of the computational mesh is studied while mathematical modeling of the inflow of a subsonic flow onto the profiles of a perspective blade with a deviating trailing edge. Verification, the convergence and correctness checkup of the solutions obtained, as well as verification on tasks having reliable and detailed enough solutions are necessary.
The objectives of this article are as follows: determining the accuracy of the numerical solution of the aerodynamic profile of the perspective blade with the deflected trailing edge, and testing the computational mesh with the potential to achieve industrial applicability. The feature in common is the use of wall-adjacent blocks adapted to geometry, applying herewith various approaches for their coupling with the external mesh. Analysis of the solvers application employing the Cartesian mesh reveals also the necessity of constructing mesh layers adapted to the surface of the body.
Analysis of existing designs allows us to draw the following conclusions. A simple deflectable trailing edge increases the lifting force by increasing the curvature of the profile. This increases the pressure on the lower surface of the profile, as well as increases its load-bearing properties.
A mathematical model of the aerodynamic processes occurring on the profile surface of a perspective blade from the back deflected edge while its on flowing by a subsonic flow is suggested.
An acceptable correlation of the results of the calculations made using structured and hybrid meshes circuits was obtained. Analysis of the results of numerical simulation employing various meshes revealed that application the meshes under consideration considered allows obtain close results. The structured meshes applied herewith consume less computation time. Hence, we will use the structured meshes as the best way to solve the problem.
Thus, the proposed mathematical model and the first method of developing the mesh can be applied to determine the numerical solution accuracy of the problem of flow past the aerodynamic profile of a perspective blade or wing with a deflectable trailing edge, as well as the mesh testing | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abdulov R. N., Asadov H. G. Spectrozonal method for detection and optimal control of low-altitude rockets through the exhaust plume of a solid jet engine. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 122-128. The problem of detection and control of rockets' launching and flying is topical from the viewpoint of functioning safety of various ground and aerial objects of both military and general assignment. At present, significant attention is paid to identification and tracking optimization of low-speed point objects' of various purposes. A method for spectrozonal detection and control of low-altitude rockets through the exhaust plume of a solid jet engine was developed and theoretically confirmed. The authors formulated new spectrozonal features for detection of launched low-altitude rockets, based on the well-known experimental results related to the study of spectral emission of rocket engines plume. To detect and control the low-altitude rockets a new spectrozonal feature, possessing experimental property useful for applying for on both axial and radial directions was formulated. The issues of identification optimization of low-speed low-altitude point objects under variable atmospheric conditions were also considered. The general mathematical problem of optimization of the entire cycle of optimization was formulated and solved. Its gist consists in achieving the maximum possible value of the averaged signal received from the object by the infrared identifier, through the accepted model of variation of atmosphere optical thickness. The article demonstrates that as applied to subsonic flying objects, such as cruise missiles, it is necessary to ensure direct proportion between atmosphere optical thickness and a certain time index. It should be considered herein that the minute scale of atmosphere optical density can be easily controlled, and it presents the result of rapid weather conditions changes due to natural or anthropogenic factors. A certain increase of the value of the functional, obtained by the performed optimization, can be interpreted as a possibility of a certain shift of the total time interval to the left. On this basis, the solution of the formulated optimization problem points to the possibility of realization of the much safe mode of an object detection and identification under revealed.
Some increase of accepted target functional caused by carried out optimization can be interpreted as possibility for some shift of whole time interval to left. Solution of formulated optimization task indicates the possibility of for safe regime for detection and identification of object upon revealed advantageous atmospheric conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirsanov A. P. Kinematic properties of aircraft concealed motion trajectory in detection zone of the onboard doppler radar. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 129-136. Onboard radars operating in pulse Doppler mode possess characteristic feature in the detection zone. This feature lies in the fact that at each point of the detection zone the aircraft has the sector of directions. Moving along these directions it, cannot be detected by the onboard Doppler radar. This sector is named as the sector of an aircraft concealed motion directions. Due to these features there are concealed trajectories, moving along which the aircraft becomes undetectable by the onboard Doppler radar, such as an aircraft airborne early warning radar (AEWR). Most of these concealed trajectories are curvilinear with variable curvature. The article is devoted to the study of the aircraft concealed movement trajectories curvature in the onboard Doppler radar detection zone. The study of the aircraft concealed movement trajectory curvature in the AEWR detection zone was carried out to evaluate the possibilities of flying over such trajectories with account for and aircraft maneuvering characteristics. The results of the study led to obtaining the equation for calculation the curvature of any concealed trajectory in any of its points. The equation allowing determine the shape and size of a region in which the movement over the concealed trajectory is impossible due to the fact that normal overload exceeds maximum aircraft operating overload. It was established that for the valid parameters of an aircraft movement and AEWR aircraft this region is located within the circle with radius not exceeding 10 km with its center coinciding the location of the AEWR aircraft. The region, where aircraft high manoeuvrability is required, presents utterly small portion of the detection zone of AEWR aircraft. Thus, the aircraft concealed movement is possible over concealed trajectory practically in the entire detection zone. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kornilov V. A., Sinyavskaya Y. A. Parametrical synthesis of actuating mechanisms with dc motors. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 137-142. One of the main problems of automatic control theory can be formulated as optimal functional links' forming between information and energy. The basic principle while control systems design consists in designing such systems, which are able to transmit or convert information with specified timing and phasing-in characteristics under condition of power consumption minimization for the given control law realization. The main power consumption relates to actuating mechanisms while synchronous transmission fr om control system to the control object with concurrent increase of the energy level. The energy level limitations in actuating mechanism affect significantly such dynamic characteristics as stability, accuracy and noise reduction. The problem of parametrical synthesis of the rudder servo drive actuating mechanism for the UAV's aerodynamic control system is interpreted as a system design optimization problem. The quality criterion of parametrical optimization problem is maximum effective power delivered to the control object from the power source, necessary to fulfill the required, most tough from the power consumption view point, motion laws of the control object (aerodynamic rudder) under specified parameters of aerodynamic load. Graph-analytic solution of the problem is based on plotting the dependencies Nmax(F), wh ere Nmax is the maximum effective power value; F = Mmax/Wmax is the robustness value of the actuating mechanism mechanical characteristic; Mmax and Wmax are the maximum torque and maximum speed of the actuating mechanism. These dependencies allow define the optimal parameters of the actuating mechanism ensuring the fulfillment of all control object's required laws of motion, provided the minimized energy consumption for their realization. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ismagilov F. R., Vavilov V. E. On eddy-currents losses determination in permanent magnets of high-speed electromechanical energy converters. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 143-150. The industry demand for high-speed electric motors with rotation frequency of 48,000 rpm to 120,000 rpm and power of 5 to 250 kW increases from year to year. A number of technological problems exists herewith, which retards the high-speed electric motors market growth. These problems relate to the issues of their output voltage stabilization, which are solved by employing static converter, stator back magnetizing, or rectifier; ensuring bearing assembly reliability, which are solved by employing non-contact bearing assembly, as well as the problems of rotor heat evolution reduction. The latter are stipulated by the complexity of fast-rotating rotor's cooling. To solve this problem, the article studies losses caused by eddy currents in permanent magnets of high-speed electromechanical energy converters. The eddy currents losses in permanent magnets and rotor retaining shell are generated by spatial harmonics caused by electric motor structural specifics, stator serration, windings diagram and distribution ratio, as well as temporal harmonics, stipulated by the external circuit, such as inverter. Moreover,with the improper selection of the electric motor parameters eddy current losses may lead to the permanent magnets overheating and their demagnetizing under the effect of this overheating. It is generally assumed, that the losses stipulated by temporal harmonics are higher than the losses caused by the spatial harmonics. This statement is valid only for a number of structural schemes of high-speed electric motors. For example, the electric motors with toothed windings feature significant spatial harmonics. And losses caused by these harmonics are higher than the losses caused by temporal harmonics. It is found that with rotation speed increasing the losses in permanent magnets have maximum point, after which they start decreasing. This is explained by the fact that with rotor rotational speed increase, the magnetic field penetration depth into the permanent magnet body and bandage reduces. Thus, the losses reduce either. The article shows also that the magnetic system does not exert a significant effect on the eddy current losses, created by spatial harmonics, in permanent magnets. The eddy currents losses in permanent magnets herewith may alter significantly due to load angle variation. The article individually considers the losses caused by temporal and space harmonics. It also presents their numerical evaluation and describes of their minimization techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalev K. L., Tulinova E. E., Ivanov N. S. Comparative analysis of magnetomotive forces of the reverced structure synchronous motor with permanent magnets and excitation windings. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 151-158. The article considers synchronous motors of a reversed structure with electromagnetic excitation of both conventional and based on high temperature superconductor tapes (HTST). The presence of excitation winding allows perform deep regulation, while current carry capabilities of modern HTS tapes of second generation allow create magnetomotive force (MMF) of the excitation winding, exceeding permanent magnets.
Synchronous electromechanical transducers of reversed structure with electromagnetic excitation open prospective application domains in wind-power engineering, low and middle power hydropower, special and military applications.
Based on analytical solution of the problems of magnetic fields distribution in active zone of electric motor of a reversed structure with both electromagnetic and permanent magnet (PM) excitation, the authors obtained equations for electromotive force (EMF) and inductive resistance. The obtained equations allow determine the dependence of motor's output parameters on the pairs of poles number, geometry of active zone, and excitation MMF. Likewise, in case of HTS tapes' implementation in the excitation winding (EW), it is possible to define the dependence of the motor parameters on the properties of the tape in use. Based on analytical equations the comparison of the motor of a reversed structure excitation MMF with PM excitation was performed. Besides, the analytical equation allowing compare these two types of excitation was obtained. It is shown, that the power of a motor with electromagnetic excitation can be greater with lower number of poles and HTS tape current close to 100 A. The obtained analytical equations can be employed for optimization calculations while defining the main sizes of a motor active zone. The combination of the presented fundamental solutions of theoretical problems and modern simulation methods will allow develop new calculation procedures for both traditional motors and motors based on HTS materials. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov S. B., Kiselev M. A., Moroshkin Y. V., Mukhin A. A., Kharchenko I. A. Combined electric power complex modular and scalable architecture for all-electric aircraft electric power systems. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 159-169. The all-electric (more electric) aircraft (MEA, РОА, МОЕТ) concept is currently the main trend in the development of the perspective aircraft power system both in the Russian Federation and abroad. This concept assumes the replacement of aircraft pneumatic and hydraulic actuators by electric (or electro-hydraulic) ones, as well as transmission generators' constant speed drives elimination. The total rated capacity of MEA aircraft electric power supply system can reach up to 1,5 MW. To ensure the specified quality of the electric energy at the consumers inputs and mutual backup, its distributing channels should e connected in paralles. Thus, each channel should contain a higher voltage (270 V or 540 V) DC link in addition to the low voltage (27 V) central distribution unit with battery. These higher voltages are no used for feeding the distribution unit buses due to the complexity of arcless commutation provision. Thus, each MEA electric power supply channel is an independent combined AC-DC complex with four types of the central and peripheral distributing units: 115/200 V, 360... 800 Hz; 115/200 V, 400 Hz; ± 27 V and ± 270 (540) V. Electronic secondary power supplies interconnect these units with each other. The authors suggest the structure of combined electric power complex with secondary power supplies' modular and scalable architecture for all-electric aircraft power supply systems with increased power-to-weight ratio based on unified multipurpose switched mode converters. This structure ensures parallel operation of both supply channels to improve electric energy quality.It reckons multiple mutual redundancy of the circuits for essential consumers feeding, and allows unify multifunctional switched mode converters, constituting it. The considered above nonconventional MPC circuit solutions provide the required electric power quality in static and dynamic modes, high specific power (per unit mass and volume) and increased functional reliability. These solutions are protected by Russian Federation priority and provide high extent of import substitution in listed products of power electronics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Marchenko M. V., Tomilin M. M. Spacecraft elements and units benchmark test on electrostatic discharges impact. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 170-175. The spacecraft onboard equipment electronic components and units, as well as cable networks benchmark testing on electrostatic discharges (ESD) resistant strength should be carried out conditions closer to the real spacecraft operation conditions, in which electrostatic discharges occur.
Benchmark tests are performed in the air medium, and electrostatic discharges are simulated an ESD-generator. Thus, drawing near real conditions of the outer space is possible only by insulating elements and units from grounding circuit and maximum offset from the conducting environment to reduce the capacitive coupling.
Establishing the standard requirements to the onboard equipment noise immunity to simulated electrostatic discharges impact allows ensuring the possibility of comparative analysis of the testing results of various space vehicles.
These standard requirements should specify the simulated ESDs types; the degree of the tests' robustness; characteristics of the working place for tests. The testing methods should account for the specifics of onboard elements and units, as well as cable network placing on the spacecraft structure.
The article presents the description and requirements for the spacecraft onboard elements and units, as well as cable network benchmark testing.
The authors suggest performing the benchmark tests in such a way that the elements and units under testing together with along with spacecraft shell element and measuring equipment would not have connections with grounding circuits and power network, and placed far from the conducting medium. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Didyk P. I., Zhukov A. A., Podgorodetskii S. G., Zabotin Y. M., Golikov E. A. Experimental evaluation of metallization quality of through holes in silicon wafers. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 176-183. Metallization of through holes in silicon wafers has been investigated by electron microscopy methods. Dependences of the thicknesses of metallization at various depths of through holes in wafers for single-sidedand double-sided sputtering of chromium and copper, with thickness of 1 µm to 5 µm, as well as with successive galvanic deposition of layers of chrome and copper and chrome and SnBi alloy (tin 98-99%, bismuth 1-2%) on the films of chromium and copper were obtained by vacuum magnetron sputtering method. Optimal modes of through holes metallization in silicon wafers process with closest characteristics of film deposition along o all structure elements, consisting in performing the process in two stages were determined. Initially, employing vacuum magnetro n sputtering method prepare metallization with minimum thickness, ensuring formation of continuous metal film. With two-sided metallization by vacuum magnetron sputtering of chrome and copper, the derived films have minimum thickness in the middle of the through holes. The continuous film is formed at chrome and copper thickness more than 1.7 µm on the surface of the through holes. To ensure the thicknesses it is necessary to perform two-sided sputtering of chrome and copper by vacuum magnetron sputtering methods with thickness less than 4 µm. Then, by galvanic precipitation method refilling to the desired thickness should be performed by galvanic precipitation method. Thickness changing at one-sided metallization sputtering, obtained in through holes by vacuum magnetron sputtering method presents linear decreasing character with increase of the holes' depth. The minimum thickness of metallization is determined, at which a continuous metal film is provided along the entire depth of the through holes in the wafers. With a thickness of less than 1 µm, the surface of the film in the through holes is not continuous, but an island one. When sprayed from the front side, a continuous film forms on the surface of the plate, but the metal structure it is not continuous on the chamfers and walls. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Solov'yanchik L. V., Shashkeev K. A., Soldatov M. A. Control method for electrically conducting properties of polymer compound. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 184-194. This article subject of research are electrically conducting polymer compounds based on epoxy binder with non-covalently modified carbon nanotubes (CNTs). Such compounds can be applied as binders to create hybrid functional polymer composites. Fluoro-organo-silicon block copolymer was used as CNTs' modifier, which is organically compatible with epoxy olygomers. It allows regulate the interaction of the modifier with polymer matrix and study the nano-composite's functional properties under various distribution of the carbon tubes. The goal of this research consists in developing a method to control electrical conductivity of polymer nano-composites by controlling the spatial distribution of CNTs in the bulk of the binder under development to create hybrid polymer composite materials with functional properties. In the course of this work execution the experimental research on the development of a method of preparation of electrically conducting binder based on epoxy resin and non-covalently modified CNTs. Measurements of electric conductivity of hardened composition were performed. Since the non-uniformity of the CNTs' distribution over the nano-composite surface does not allow determine the value of the surface resistance with adequate accuracy by contact methods of conductivity measuring, the non-contact method was used based on measuring the electromagnetic wave reflection coefficient within the range of 20-35 GHz. The authors measured also the viscosity of the binder and determined the spatial distribution of nano-particles in the bulk of composition by scanning electronic microscopy and determination of element composition. The effect of the modifier concentration on electrical conductivity and rheological properties of the binder was studied. It was established that the modifier concentration variation allows regulate electric conductivity of nano-composite and viscosity of modified binders under the constant concentration of CNTs. In the course of this work we obtained the values of electric conductivity of about 7.3 S/m with the viscosity of the developed binder comparable to the basic binder. The results of the study allow solve technological problem of decreasing the viscosity of epoxy binder modified by carbon nano-particles, to produce electrically conducting hybrid polymer composite materials under conductivity preserving. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nochovnaya N. A., Nikitin Y. Y., Gudkov S. V., Savushkin A. N. VT20 titanium alloy properties estimation after removing of operational carbonaceous impurities by chemical means. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 195-202. The lack of information in domestic and foreign sources on the effect of carbonaceous impurities purification technology on titanium alloys' properties complicates for technologists selection of the most effective and safe methods of purification of a gas turbine engine compressor air-gas channel parts and units.
The purpose of this work consists in evaluating the property change of VT20 titanium alloy while removing carbonaceous impurities by chemical means.
The studies were performed with laboratory samples manufactured from a VT20 alloy sheet-billet. Caronaceous impurities, imitating operational ones, were applied on a number of samples according to the developed technology.
Eight foreign made and domestic chemical technologies (compositions) were studied as purification means.
The authors established that the most effective removal of the carbonaceous impurities from the surface of the heat-proof VT20 titanium alloy was ensured by domestic purifying solution No 1, a two-stage purification technology in alkaline and acid solutions (“loosening + etching”), and foreign made solution HDL 202. However, while purifying carbonaceous impurities with HDL 202 solution a general etching of the surface and its microstructure change might occur.
The surface roughness values of the VT20 titanium alloy do not change significantly after the removal of impurities. The relief and profiles of the purified surfaces have a shape similar to those of the original samples.
A slight increase in the microhardness of the purified samples (up to 5%) can occur due to gas saturation of thin surface layers, due to both formation of carbonaceous impurities and the processes of chemical surface purifying.
When purifying the surface from carbonaceous impurities, the activity of the surface decreases, regardless of the type of the solution used. The least decrease in activity is ensured by cleaning solution No 1.
There is no deterioration of moistening characteristics by the VPr16 solder of the surface purified from the carbonaceous impurities by purifying solution No 1 or two-stage “loosening + etching” technology and HDL 202 solution.
Purification of carbonaceous impurities by all studied solutions does not lead to VT20 alloy strength and plastic characteristics degradation, and to a change in the character of its destruction under conditions of static loading. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grigor'eva Y. A., Omel'chenko I. N. Orders formation and realization process organization system in the context of their life cycle. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 203-212. The article presents specifics of orders formation depending on their basic characteristics.
The presented work discloses the fact that at present the system of orders formation and realization process is of paramount importance. This is important so that the orders themselves should be dealt with in the context of their life cycle. The orders can be split between each other according to such parameters as volume, liability distribution while their fulfilment, delivery periods and formation method. The process of the order commissioning or the order lifecycle can be conditionally split into certain stages. The life cycle stages would differ from each other for various types of the order commissioning. Therefore, one should have an idea of an order life cycle specifics for various types to minimize the error occurrence probability in strategy selection, and, as a result, minimize the probability of financial losses risk occurrence.
The article consists of three main parts, namely, introduction, the gist of the work and conclusions. It presents the description of various stages specifics, and determines the relationship of the enterprises activities marketing component and the logistic one. An algorithm for the order maintenance was developed, and efficiency evaluation technique is presented for one of the order types.
Finally, the authors describe the orders formation technique through the Internet media and its efficiency evaluation tool. The article presents the basic technologies for the delivery of the order, best suited to the market demands.
Eventually, it is worth noting that companies should master orders fulfilment and maintenance methods through Internet medium, since at present this is the prospective trend of development. Besides, these methods are fast and economically sound as well. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Terent'ev V. B., Terent'eva A. V. Ideal point method modernization. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 213-220. When solving the problem of objects' multicriterion selection and seriation, modern mathematical modeling technologies can employ various methods, including simple aggregate weighing (SAW) and “ideal point” (TOPSIS) methods. When comparing alternative objects of research by their effectiveness, the necessity occurs to account for not only positive or negative indicators, but estimate the objects by the degree of proximity to a specified value, i. e. to the criterion. It should be noted, that the criterion value could lay in the middle of the range of the considered indicators. Besides, the object's effectiveness, as a rule, has non-linear dependency from the change of the indicator value. Inasmuch as the existing algorithms of SAW and TOPSIS methods do not allow perform such task, a certain modernization of the TOPSIS method is required. This method is top-of-the-line with respect to the ranking procedure.
In general, when the case in hand is the indicator's degree of proximity to the specified value, the attainability function is used. In multicriterion analysis, it is called the utility function. It allows realize transformation of the initial “decision matrix” system into normalized matrix, with account for the proximity to the specified values of the criteria. This operation is close in its meaning to linear (nonlinear) normalization. It is performed in the SAW method (determines the degree of the maximum or minimum attaining), and replaces the rationing using the TOPSIS method.
Earlier, the TOPSIS method could be applied, when a monotonic-increasing utility function existed for each criterion. In other cases, one had to apply the more simplified SAW method.
The presented TOPSIS method modernization gives, firstly, practically a comprehensive agreement of the computational results with the above said methods for positive indicators, and, secondly, a slight difference with the SAW method while using positive and negative indicators, when the unknown function of the relationship between efficiency and indicators is non-linear (linear and non-linear normalizing).
Thus, the proposed modernized version of TOPSIS method allows extend the scope of this method in the case of the specified criteria values (positive and negative), located within or outside the range of the indicators variation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korshunova E. D., Smirnov S. D. Methodical approach to industrial startup development management mechanism efficiency determination. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 221-225. Startups become the benchmarks of innovation growth, and the government is interested in their successful functioning. It is proved by the formation of support infrastructure around startups. An integrated approach is required to startups' support realization.
The article describes the life cycle model of a startup. Irrespective of the startup's type and line of activity, each of them passes typical stages in the course of its development. The startup lifecycle model is associated with the I. Adizez's model of the organization lifecycle.
In the beginning of their functioning, most startups face with the necessity of solving the similar problems and performing the similar functions, particularly with the necessity of the substantiated selection of the way of their development.
The management mechanism of industrial startup development allows obtain a justified choice of the way for its further development. The participants of an expert group obtained a conclusion on the most effective method by carrying out the procedure of a startup development evaluation. However, it is necessary to ensure the effectiveness of the taken decision.
The expediency of applying the mechanism and the efficiency of the taken decision should be confirmed by calculations of economic efficiency. Thus, the methodological approach to the management mechanism of the industrial startup development becomes a crucial issue. All approaches consider the object of evaluation from certain sides, and are based on specific external and internal information.
The article describes the approach to efficiency determination of the industrial startup development mechanism management. A structure for calculating the total costs of a startup during the period of itscommercialization with the chosen development process was developed. A typical process for analyzing and calculating the total costs of a startup is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Manvelidze A. B. Status analysis and forecast of operated aircraft writing-off. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 226-234. Monitoring of the current state of the aircraft fleet is an essential component of the management process of the aircraft fleet renewal by introduction of new types of aircraft with improved technical and economic characteristics.
The branch (Federal Air Transport Agency -Rosaviatsya) does not supervise (keeps record) on such deals as purchase and leasing of foreign made aircraft operated in Russian Federation. We mean the monitoring with respect to concrete transaction number, the date of leasing commencement and its expiration.
In this connection, the problem of such aircraft retirement from the Russian air transportation market is difficultly formalizable. This analysis was based on publicly available databases Flightglobal (http:// dashboard.flightglobal.com/app/fleet/#/analyser/fleet), contract data and published reports on big deals of the companies.
For the purposes of the analysis the operated aircraft was separated into several groups according to ownership types and aircraft age. These groups are as follows: the aircraft owned by air carrier; aircraft obtained by financial leasing (from which the author separated out the subgroups of “young” aircraft, the aircraft with life span lower than 12 years, and the aircraft with life span more than 12 years); the aircraft in back leasing and operational leasing.
The owned aircraft retirement was determined according to the expected life span, or maximum permissible flying hours and endurance cycles from the commencement of operation.
The retirement of an aircraft being in financial leasing or leaseback can be forecasted only by life the span and total operating time.
Meanwhile the economic mechanism of the transition of the second-hand aircraft from the big companies to regional Russian companies is not developed.
The article presents some results covering the general situation in passenger aircraft fleet in the branch at large, and more detailed on Aeroflot Russian Airlines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Luk'yanova A. A., Kononova E. S., Belyakova E. V., Smorodinova N. I. Possibilities of sustainable social-economic development of the northern territories. Aerospace MAI Journal, 2017, vol. 24, no 4, pp. 235-240. At present, the problems of sustainable development of socio-economic systems of various levels are in the sphere of close attention of Russian and foreign scientists.
The goal of the article consists in considering the possibilities of sustainable development of the northern territories, which have pronounced specific features. To clarify the concept of sustainable development of the northern territories, the article reveals limitations in the use of their resource potential, namely: high level of production costs, high vulnerability of the natural environment, preservation of the traditional way of life and the need to improve the quality of life of indigenous small peoples.
Based on the revealed limitations, the article formulates the principles on which the sustainable social and economic development of the northern territories should be based, the priority role of which is assigned to the implementation of the latest technologies to ensure high quality of life for the population and improve the ecological situation.
Remoteness of the Northern Territories from large settlements, its difficult climatic conditions, and the poor development of land infrastructure predetermine the high importance of air communication for the sustainable social and economic development of the North. Thus, the latest technologies used for the development of the Northern Territories can be concentrated in this area.
The article analyzes the experience of Canada and Alaska in the development of air communication. These areas were selected for analysis due to fact that natural and climatic conditions, labor endowment provision level, the distance from the economically developed regions allow establish certain similarity of these territories with the territories of the North of Russia.
Based on the performed analysis of international experience, the article suggests the following opportunities for using modern aviation and space technologies to ensure sustainable social and economic development of northern territories:
– Development of hub airports, as well as regional and local air transportation, supposing inclusion of regional and local airports into nodical structure of air transportation servicing;
– Implementation of unmanned aircraft for the delivery of goods;
– Implementation of high- capacity space communication vehicles to create a broadband satellite communication network;
– Remote sensing of the earth surface for natural resources development while meeting the requirement to preserve the unique ecosystem of the North.
The considered technologies are quite expensive and require significant investments in research and development. In this regard, the opportunities for sustainable socio-economic development of the northern territories are closely associated with the role of the state in socio-economic development.
The article concludes that the formation of an effective system of interaction of federal and regional authorities, business and indigenous people, the optimal combination of market mechanisms and public administration tools will ensure the implementation of opportunities for sustainable social and economic development of the northern territories and level the specifics of these territories that complicate this process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galkin V. I., Paltievich A. R., Shelest A. E. Modeling and evaluation of defects occurrence reasons while isothermal punching of ribbed panels from aluminum alloys. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 170-178. Ribbed panels from aluminum alloys are widely used in aircraft industry as power structural elements, parts of the wing and fuel tanks, as well as in the form of the heat-exchange surfaces. Increased requirements on strength and reliability are rendered to such panels. The most rational technique for such kind of panel manufacturing, i. e. isothermal punching, may lead to clipping in the ribs and sink marks on the side, opposite to the ribbing. Modeling and experimental results of the studies reveal that defects stems from the combination of manufacturing process control parameters, such as temperature and deformation velocity, as well as geometrics, i. e. blank thickness. The main objective of the studies consists in developing design technique of the part blank design as a function of temperature and deformation velocity while isothermal punching. The put forward problem is solved by control polynom development, linking manufacturing process parameters – the blank temperature, velocity and geometrics with the defect magnitude, i. e. sink marks in the ribbed aluminum panel while its manufacturing by isothermal punching technique. The initial data for the required polynomial is the results of finite element mathematical modeling with varying initial parameters of the punching process and the magnitude of the forming sink mark or its absence. The obtained modeling results were processed according to the three-way analysis of variance planning procedure. The regression equation was obtained to compute the sink mark magnitude in the ribbed panel in dependence of the process temperature and velocity, as well as the initial blank thickness. The authors applied the analysis of variance, which allowed define the significant factors in the calculated polynomial, and, neglecting the rest, significantly simplify it. The sink mark magnitude obtained with the calculated polynomial correlated well with the results of mathematical modeling and experimental studies. The proposed method is universal and can be implemented for various cases of defect-free technological processes design, when evaluating the impact of the process's control parameters on and their contribution to the manufactured product's characteristic being studied is required. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eremeev N. V., Eremeev V. V., Kondyukov S. L. Technological specifics of manufacturing of anodes based on aluminum-indium alloys system for chemical current sources. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 162-169. Presently, one of the meaningful problems in modern machine building consists in creating new electric power sources. It is of special importance for such human field of activities as aircraft and spacecraft building. Chemical current sources (CCS) based on aluminum anodes, where various solid, liquid or gas oxidizers used as cathodes, found an extensive application in spacecraft electric power systems. Very often, the modern methods of such sources design, however, turn out rather complicated and energy consuming. One of the most successful electrical systems based on CCS, applied in modern spacecraft, is an oxygen-aluminum system with liquid electrolyte, consuming oxygen from the environment. In most cases, anodes are made of aluminum alloying with such metals as Ga, Sn, In. Nevertheless, the high values of anode potential and current were obtained while the experiments with Al-In alloy anode. It was found, that aluminum doping with Indium ensures anode electrochemical activity with faraday efficiency no less than 90%. Thus, this work was focused on developing the scientifically substantiated technology of anode manufacturing based on Al-In alloy to ensure highly dispersed, isotropic structure to provide a uniform anode dissolution, decreasing pitting formation, and, as a consequence, increasing energy and performance characteristics. The main difficulty while Al-In alloys casting consists in organizing a uniform indium particles distribution (which is not soluble in a solid aluminum) over the solid base metal volume. The reason to it stems from too large difference between aluminum and indium melting points (659°C and 156°C respectively), as well as high density of the latter (6.5 g/cm3). Introduction of traditional modifiers into the alloy is unacceptable, since they (Ti, Zr, B) aggravate the electrochemical figures. The studies conducted in MAI (laboratory UNPL “TOMD”) allowed develop technological scheme for obtaining anodes' blanks. The scheme includes obtaining ring blanks using additive technology of centrifugal casting and pressing by using shear deformation during pipe billet extrusion. It will allow work out sufficiently the alloy structure, grind up the phase inclusions and, as a result, ensure the necessary properties' level. A distinctive advantage of the developed technology compared to the analogues is the possibility of regulating of a significant number of factors during the deformation process and, accordingly, to obtain the best possible material's characteristics in the final product. This technology is realized herewith using traditional equipment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolesnikov A. V., Kolesnik A. V., Zabolotskii A. P. Pneumo-thermal molding of sandwich wedge-like panels from titanium alloy VT20. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 155-161. The presented work deals with considering pneumo-thermal molding and diffusion welding (PTM/DW) technology for multilayer structures manufacturing from titanium alloys, including the ones of variable height. The paper represents the presentation of general theory of the above said technology, and analysis of the problems emerging while its realization. The author separated out the stages of PTM/DW technology of multilayer titanium panels. The main problem considered in the paper consists in the problem of non-removable defects formation, accompanying manufacturing of multilayer wedge-like panels. These defects are imaged on the appended plots and figures. The reason of these defects occurrence while multilayer panels molding lies in the different displacement of the lower shell in various areas of the pack of sheets. In the area of diffusion welding this displacement is constrained by ribs of the filler, while in the zones which are not welded with the filler, the upper shell is forming freely under gas pressure. Its deflections are forming herewith between the areas of welding with the filler. Solution of this problem consists in defining the managing program, necessary to form the ribs of the filler and the shell, whereby the shell deviation in the areas unreinforced by the ribs would not reach critical value. The recommended range of the shell and filler thicknesses ratio in dependence on the shell deflection in the areas unreinforced by the ribs, as well as equations for determining critical deflection factor and molding pressure were obtained by mathematical modeling. Application of the above said equations for the filler and shell thicknesses of multilayer wedge-like panels will allow avoiding defects occurrence, which was confirmed in practice. All fabricated panels comply with the calculated parameters. No defects were detected over the profile section dimensions. In view of the foregoing, one may state that the problem consisting in determining the regularities for selection of design and geometry parameters of multilayer structures, allowing ensure qualitative molding process without defects formation was solved successfully, and the solution has practical applicability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ismagilov F. R., Vavilov V. E., Tarasov N. G., Aiguzina V. V. Integrated high-temperature starter-generators with intermittent concentrated winding. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 143-154. The main objective of the research is the direct integration of the electric machine such as generator or starter-generator on the low-pressure and/or high-pressure shaft of an aircraft engine, and the gearbox elimination. This will allow reduce the aircraft engine's weight and size figures, as well as improve the aerodynamic efficiency of an aircraft as a whole. This article presents the design and experimental research of the scalable prototype of high-temperature starter-generator with the inner rotor for more electric aircraft. The fundamental difference of the developed generator from the conventional machine consists in no oil ingress into the rotor or stator cavity. The starter-generator is immersed in an aircraft engine oil chamber, containing the oil necessary for bearings lubrication at the temperature of 120-160 °С. The stator and rotor are not lubricated with oil, which does not circulate. Cooling is achieved by losses' heat sink into the surrounding oil. A scalable high-temperature starter-generator prototype model was developed in Ansys Maxwell software package. It revealed a high accuracy and close convergence with the experimental results. Moreover, the system efficiency assessment and computation of losses in starter-generator's elements were performed. Based on the experimental results and computer simulation the starter-generator full-sized model was developed, and tests at the temperature of 120 °С were conducted. This generator appeared to be less loaded from the viewpoint of electromagnetic and thermal loads. It proves the efficiency of the proposed conception and its effectiveness for implementation in more electric aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komov A. A. IL-76MD-90А aircraft competitiveness recovery. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 7-12. The paper compares competitiveness of Il-76MD-90А with the US C-17 military transport aircraft. The basic assessment criterion is the aircraft capability to perform landing on unprepared sites with restricted run length, which requires employing the engine thrust reverse. The problems under discussion relate to employing thrust reverser of PS-90A-76 engine, installed on the Il-76MD-90А aircraft. These problems do not only increase the cost of an aircraft operating cycle and affect the flight safety, but reduce its competitiveness as well. The paper presents computation and experimental data, revealing that the main cause of the emerging problems consists in poor external aerodynamics of the power plant during an aircraft ground run employing the thrust reverse. By external aerodynamics the authors mean the gas jet discharge type form the engine reverse units, which may interact with the engine itself and control airframe surfaces while its ground run. Such interaction can lead to: – gas dynamic instability in engine operation; – damages to the rotor blades of the engine caused by foreign objects thrown from the surface of the aerodrome; – Aircraft dynamic characteristics deterioration (wind drag, stability, controllability), and aircraft run-length increase. Unsatisfactory external aerodynamics of the Il-76MD-90A aircraft is the cause of its poor competitiveness compared to the US military transport aircraft S-17. Ways to the aircraft external aerodynamics improvement are considered below: – the engine reversal thrust value optimization; – reverse jets discharge optimization in accordance with the aircraft layout. Ways of the Il-76MD-90A aircraft external aerodynamics improvement were developed based on estimated and full-scale studies. The substantiation of the developed measures is based on the design features analysis of the S-17 engine reverser unit. From the above said the author concludes:
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Baklanov A. V. Stepwise gas turbine engine combustion chamber development in conditions of air velocity forcing at compressor outlet. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 13-22. Development of new up-to-date actuating gas turbine engines based on fourth generation aircraft engines requires certain time consuming. Thus, one of the ways to series-production engines' parameters improving consists in their upgrading and forcing. A fifth series-production NK-16-18ST engine was developed hereupon at SC KMPO. Its more productive high-pressure compressor allowed ensure higher flow velocity (about 170 m/s) at the combustion chamber inlet. Combustion organization and provision of optimal level of toxic agents' emission in engines of such kind is hindered due to high-pressure parameters of the airflow. Such situation led to the necessity for carrying out research and design effort consisting in altering structures of burner and flame tube with redistribution of air vents along its length. The approach, used in the above said structure lies in forming the «reach» mixture in combustion chamber primary zone with its subsequent sharp weakening to ensure “poor” content, which allows maintain low level of nitrogen oxides. Testing of this chamber together with the engine confirmed that the sel ected approach allows reduce nitrogen oxide content in combustion products. However, it requires a number of measures related to the structure changes to achieve the desired level of noxious substances emission. To increase penetration depth of a jet into combustion zone the chamber was upgraded by cylindrical hubs installation in the first row of vents. This measure allowed reduce concentration of oxide nitrogen emission in the engine's exhaust gases, but it was not enough to ensure the level, required by regulations. Having in mind, that residence time reduction of gas in high-temperature zone decreases oxide nitrogen formation, in the framework of the last version, measures were introduced to increase fuel mixture flow velocity fr om atomizers, mounted on the flame tube head. The atomizers have elongated nozzles and less diameter. Such configuration allowed ensure noxious substances emission in combustion products at the level complied with the State Standard requirements (GOST 28775-90). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Piunov V. Y., Nazarov V. P., Kolomentsev A. I. The upper stage oxygen-hydrogen rocket engine energy characteristics improvement by structural scheme optimization method. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 23-33. The informationally and navigationally oriented spacecraft injection to the working orbit with high positioning accuracy, scientific and research spacecraft transition from support orbits to departure trajectories for deep space flight and other complex tasks of space exploration are carried out by rocket transportation systems. These systems include specialized withdrawal means, named “upper stages”. The following requirements, such as enhanced energy efficiency and reliability, long-term staying in starting readiness mode, protracted operating time and multiple starts are imposed on upper stages' cruise engines. The «liquid oxygen-liquid hydrogen» cryogenic pair burning engines possess maximum energy efficiency. The first home-produced oxygen-hydrogen LRE is 11D56 engine developed at Khimmash Design Bureau headed by A.M. Isaev. This engine can be considered as the basic one for ecologically clean upper stages for rocket carriers of “Angara”, “Soyus 2-16” and “Soyus 3” families presently under development. This engine's design allows modernization or modification (without significant time consumption) of its structurally stand-alone units, preserving characteristics, which define the engine workability and reliability at large. The KVD1 engine energy parameters and characteristics updating is realized by structural scheme optimization based on the structure technical analysis and effective options selection, related to the engine usage tasks. Based on the experience in the KVD1 engine chamber design and development two options for chamber with retractable nozzle headers design were considered. For these options, corresponding to the two engine modernization variants, optimization of nozzle divergence geometric degree was carried out. Calculation of working process parameters and the main chamber characteristics optimization was performed. The specific impulse's increase is analyzed by optimum relationship selection of fuel components consumption and selection of the maximum (optimal) pressure in the combustion chamber selection. The optimality criterion of fuel components consumption is payload weight maximum at geostationary orbit, at which, according to the specific impulse mass equivalent, the mass gain is equal to the fuel tanks of the engine unit the mass gain. the results of theoretical and calculating studies consists in defining principal design solutions of two variants of oxygen-hydrogen engines' chambers, under development based on KVD1 LRE. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goza D. A. Development and investigation of laboratory model low-thrust thermal catalytic thruster on “green propellant”. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 34-42. “Green fuel” is an aqueous solution of a high-energy oxidizer (hydroxylammonium nitrate and others), and a fuel, presented by various substances, such as alcohols, glycerin, etc. It offers a number of advantages, namely, a higher density, low freezing temperature and high specific characteristics. Such mixtures relate to low-toxic substances, whereas hydrazine is a high-toxic substance. Thus, the “green fuel” mixture implementation as a monopropellant for an aircraft correction and orientation thermocathalytic thrusters is up-to-date issue. Hydroxylammonium nitrate was sel ected as a basis for the “green fuel”, to which a fuel and dissolvent (water) are added in calculated ratio. The energetic qualities of the fuel depend on its basis, though its output characteristics are strongly affected by the water content in the mixture. The laboratory model consists of a heater for the structure's starting warm-up of the, combustion chamber fr om refractory metal with a special protective coating, catalytic bed, consisted of a combination of metallic and granulated catalysts, an injector unit ensuring operating pressure differential, and a system of thermal screens. The laboratory model presents a disassembling model to monitor separate elements of the structure. Besides, such model allows quick replacement of the thruster elements, such as the catalyst bed. The laboratory model was tested in air under normal climatic conditions. The thruster was tested on firing functioning both in impulse and continuous operating modes. The tests of the thrusters were conducted in continuous modes at the inlet's dropping pressure. It is worth mentioning that with the inlet's pressure decrease, the pressure in the combustion chamber decreases proportionally, which demonstrates the stability of the thruster operation. The K100E laboratory model maximum run amounted to 1.5 kg of consumed fuel over 1500 start-ups. The main reason for the thruster's failure relates to the tests conduction in atmospheric conditions, namely to the oxidizing and destruction of separate parts of the laboratory model (heater, screens) under higher operating temperatures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Maximov N. А., Solodovnikova D. A., Sharonov A. V. Mobile system for fixing and accounting for aircraft external damages while preflight checkup. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 43-50. The paper tackles the version of the mobile system for fixing and accounting for aircraft damages while preflight checkup. The benefits of the system are defined by the possibility to use mobile devices of a tablet type equipped with high-resolution cameras. These devices fix the detected damages, and convey the images of these damages into the server part of the system, which performs their processing and automatic logging to various exploitative documents, related to aircraft servicing. The basic tasks resolved by the developed and described in this paper bundled software of the mobile system are formulated as follows: The developed mobile system's software solves all above listed tasks, which allows accelerate not only the preflight checkup itself and filling out the related documents, but also the subsequent technical servicing (such as repair, gathering of statistical reporting systematization on the condition of the certain aircraft
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Chukhlebov R. V., Loshkarev A. N., Sidorenko A. S., Dmitriev V. G. Experimental research of an aircraft product's structure vibrations under flight loads action. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 51-59. One of the main factors affecting reliability of aircraft articles is vibration effect during the joint flight with carrier. To obtain estimates of reliability characteristics flight test of products are carried out. Modern equipment for ground vibration testing, reproducing the flight conditions, allows substantially reduce the amount of flight tests by replacing them with laboratory tests. The actual problem here is formation of laboratory tests regimes to ensure the equivalence of loading in laboratory conditions and in flight. Characteristics of vibration loads are obtained usually based on measuring data obtained during flight tests of the product or its prototype. At vibration tests, a relation is established between laboratory test modes and flight dynamic loads by the levels of vibration accelerations or stresses. The paper presents the technique and results of flight and laboratory vibration tests on definition of vibration stresses and accelerations characteristics of an aircraft product's structure in typical flight. Laboratory tests were conducted with random dynamic loading, corresponding to loading during flight structural tests. The purpose of laboratory tests is determination of characteristics of a structure's accelerations and stresses in the conditions of a spacecraft joint flight with the carrier. This requires reproduction of conditions exhibiting adequately enough the loading condition of a product according to the basic probabilistic characteristics during typical flight. The authors developed the technique and modes of aircraft product's vibration tests, complying with vibration loading of a product at every stage of the host aircraft flight. Using the obtained modes the tests were conducted, whereby the random dynamic loading, corresponding to the operation conditions of the product on an internal suspension bracket of the carrier, was realized. Comparison of vibration acceleration probabilistic characteristics at laboratory and flight tests demonstrated conformity of these tests' results according to root mean square values of vibration acceleration. The developed laboratory tests technique ensures correct reproduction of random vibration loading reproduction of and aircraft product structure during the flight on an internal suspension bracket of the carrier. The technique and results of the tests can be applied for estimation the structure vibration strength of an aircraft product of various applications during the joint flight of an aircraft product with the carrier. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pashko A. D., Dontsov A. A. Guided missile trajectory and active protection element movement determination errors design procedure. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 60-71. At present, the onboard aircraft defense structures for protection from “air-to-air” missiles are equipped with the systems of jamming cartridges of various calibers ejection. The existing algorithm of airborne defense systems application consists in practically continuous ejection of a series of jamming cartridges when the aircraft enters the area of the enemy's air defense. However, the existing techniques of jamming cartridges implementation do not ensure the aircraft protection from the missiles equipped with matrix photodetectors. There is a contradiction between the potential onboard defense systems implementation efficacy, and military characteristics of existing onboard defense systems. In this paper, the authors propose a technique for guided missile coordinates determination errors to ensure its neutralization on the flight trajectory. A methodology for probability estimate of aircraft skipping the hit by a guided missile while realizing the active element ejection to the trajectory of the guide missile with its subsequent detonation was developed. The probability estimate of guided missile missing its target is based on probability calculation of the active element's detonation coordinates center will appear inside the dispersion ellipse with the main axes equal to mean square deviation of the active protection element detonation coordinates from the actual position of the missile. The equations for the active protection element detonation coordinates were obtained using measuring errors theory methods on the assumption of the aircraft and missile rectilinear and steady motion, after the initial miss elaboration, with an allowance for the aircraft and missile coordinates and flight speeds measuring error, as well as current missile's angle of attack determination errors. The paper shows that the missile's angle of attack determination errors depend on aircraft and missile current speeds determination errors, as well as missile bearing in vertical plane measured by optical radar station or specialized onboard radar station belonged to aircraft protection structure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Popov A. S. Analysis of the capacity to use a repulsive two-mass space system with periodically formed coupling to perform interorbital flights. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 72-77. At present, methods for orbit parameters changing with cable system by periodical changing of its length for the case, when the cable is located in the plane orthogonal to the orbit plane, or when it lays in the orbit plane, are known. However, the orbit parameters changing is possible only in case of non-central gravity field. The presented paper offers the structure of interorbital transfer of the space system, consisting of two masses repulsed and retracted in the orbit plane by periodically formed coupling. The flight is considered in the central gravitational field. Originally, the system represents a single spacecraft, consisting of two parts of equal weight. Initially, the system s on a circular orbit. The mass repulsion occurs in the direction tangent to the trajectory. Hereafter, the masses being uncoupled move independently of one another over various trajectories. Performing a various number of turns around the attracting center, after a certain period of time they will turn up on the line coinciding with the radius vector. One of the masses herewith will pass the pericentre of its orbit, while the other – its apocentre. At this moment, the masses contraction occurs assisted by the formed coupling. Methods of coupling formation are not considered in this paper. The paper demonstrates that the eventually formed orbit differs from the original one. The authors obtained analytically the dependence of the system final velocity in the point of masses contraction after their contraction versus the speed of their repulsion ΔV.
The dependence of the masses contraction point radius vector versus the initial repulsion speed ΔV for the final orbit.
Here: Solution of this problem revealed a theoretical possibility of orbit parameters changing for the system of a proposed type. The analytical dependence of the speed value at the time of contraction versus the initial masses repulsion velocity is obtained. The equation determining the radius vector in the point of masses contraction of the formed final orbit created. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vereshchagin Y. O. Deck-based aircraft aileron adaptive control technique. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 78-82. Active development and application of digital technologies enabled realization of advanced algorithms in aircraft control systems, which could not be implemented earlier due to the limited capabilities of analog computers, and the more, so in mechanical control systems. The attempts to ensure aircraft control characteristics invariance to varying flight conditions, aerodynamic configurations, centering and mass-inertia characteristics led to the necessity of employing two classes of characteristics onboard the aircraft, namely, with reference model and with the identifier. Such algorithms are developed and successfully applied in the control systems' longitudinal channel of Su-30Sm, Jak-130, Su-35 and Т-50 aircraft. It is important to notice that the adaptive algorithms in lateral control channel have not found practical application, though the problems requiring solution exist there either. Thus, the problem of lateral controllability deterioration caused by occurrence of the adverse moment in yaw during aileron deflection exists on all MiG-29 modifications. The aircraft heel moment caused by lateral static stability due to the sliding is directed opposite to the effective aileron roll control moment. Flight speed reduction and increasing angle of attack corresponding to it lead to reduction of available rate of roll, and in limit case to occurrence of roll back reaction to control stick deflection. The acuteness of the problem is partially reduced due to implementation of a unique structural solution, i. e. airspeed head wind eddies generators, which, however, does not eliminate the problem at large. The situation is aggravated in the case of external suspension brackets asymmetrical mounting, which becomes a standard situation in view of the increasing effectiveness of aircraft means of destruction. The aircraft herewith begins to react differently to the stick deflection to the suspension bracket side and to the side, opposite to it, by the rate of roll. It complicates substantially delivering air combat and ground targets attacking, accompanied by drastic banking maneuvers of positive sign to negative and vice versa. Aircraft landing approach control is rather complicated, especially in case of landing on a ship deck of limited size in conditions of oscillatory motion and atmospheric turbulence. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gurevich O. S., Golberg F. D., Petukhov A. ., Zuev S. A. “Virtual engine” software usage for air bleed control in gte units' cooling systems. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 83-94. One of the trends of gas turbine engines perfecting consists in “intelligent” engine developing. Within its control system, a so-called “virtual engine” functions in real time mode, i. e. a full range thermo-gas-dynamic GTD model. Its implementation allows, in particular, realize engine control by its critical parameters inaccessible for measuring. The gas temperature in the hottest part of the engine duct, i. e. the temperature at the turbine inlet, is one of such parameters. The paper presents the result of the study of new turbine cooling control methods, differing fundamentally from conventional indirect open-loop control of air bleed valves according to rotation speed, employed in modern automatic control system. A block diagram and algorithmic provision of adaptive closed loop control of turbine cooling units operating directly according to gas temperature prior to the turbine and rate change of turbine blade temperature are considered. The result of such type of control estimation, carried out as applied to modern turbofan engine with high bypass ratio, revealed that its' implementation may allow: – Engine efficiency increasing by decreasing the bleeding air consumption; – Engine lifetime increasing by turbine inlet temperature decreasing by 100...200 К at steady-state modes, and the rate of turbine blade temperature decreasing by more than 20% at transient modes. An adaptive control of air bleeding for turbines cooling associated with gas temperature limitation by effecting on the fuel flow in the combustion chamber was considered. The paper demonstrates that its implementation is possible: – In flying conditions, when maximum engine thrust is required. It can be increased by 10% with the maximum allowable limitation of turbine blade temperature; – Under operation conditions when engine lifetime is critical. It allows blades temperature reduction by approximately 50 K while maintaining the thrust value and specific fuel consumption. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bilyaletdinova L. R., Steblinkin A. I. Mathematical modeling of electromechanical steering gear with ball-screw actuator with account for nonlinearities of “dry friction” and “backlash” types. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 95-108. The paper addresses the multi-purpose mathematical model of the electro-mechanical actuator's (EMA) dynamics. It contains the general description of the EMA, which was the object for the modelling, the description of the mathematical model developed and mathematical modeling results. The actuator was developed in the frame of the Russian-European project called RESEARCH for the elevator deflection of a regional passenger airplane. The mathematical model was implemented within MATLAB/Simulink software. The actuator model consists of four submodels of its physical constituent parts such as controller, power electronics block, electric motor and mechanical gearbox (ball screw transducer). Programmatically switchable models with various level of detail of physical processes were realized for each part. The electrics were realized by the submodels of a single-phase DC motor and a simplified controller corresponding to it. It also contains three-phase induction motor with permanent magnets, regulated by a controller, realizing vector control in {p, q}-coordinates. Power electronics is modeled either by simplified dynamic elements, or on a physical level in detail (electronic components level). Special attention was payed to mechanical part of the actuator modeling, i. e. various submodels of non-linear mechanical effects of a “dry friction” and “backlash” were realized. Thus, we managed to ensure a balance between modeling accuracy and speed within the framework of a single model. Based on mathematical modeling results the paper demonstrates how the dry friction and backlash parameters, as well as software methods of their realization effect on the actuator's regulation quality and its characteristics. It shows that program splitting of the actuator states (idle, motion, initiation) based on velocity smallness without using the sign function approximation is optimal method of dry friction effect accounting. It ensures reproduction of the necessary actuator motion pattern with acceptable integration step (10-4 s). The paper demonstrates also that accounting for linear stiffness of the actuator's ball screw transducer has insignificant effect on the actuator's frequency response within the frequency range of control surface control. It is shown that the replacement of the three-phase motor with a single-phase one while reducing the EMA model leads to different regulation character even while using the similar regulator structure and comparable PID-regulator coefficients. The developed model can be used while the electromechanical flight control systems design for various engineering tasks, characterized by significantly varyng requirements imposed on the model in use. These tasks include: 1) development of the actuator and its control system, including actuator digital regulator synthesis; 2) actuator static and dynamic characteristics express-analysis; 3) obtaining reference actuator characteristics including small control signals; 4) analysis of transient responses and stability margins of the closed “aircraft – flight control system – actuator” control loop, including in-line simulation; 5) study and optimization of actuator thermal conditions while operating in the closed bay of the outer wing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nadaraia T. G., Shestakov I. Y., Fadeev A. A. Aircraft landing gear wheels actuator. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 109-113. According to the item of the State Program “Development of the aviation industry for 2013–2025” creation of scientific and technological capacity ensuring global leadership in aviation technology and product promotion of domestic aviation industry on the domestic and foreign markets should ensure high competitiveness of domestic aircraft by introduction of innovative developments. Operation and maintenance analysis of the existing civil aircraft park revealed that while aircraft aerodrome maneuvering the hundreds of kilograms of kerosene are wasted, and drive trucks waste tens of kilograms of fuel. When kerosene burns in an aircraft engine, and fuel burns in combustion engine the atmosphere is contaminated by noxious substances. While aircraft maneuvering on the runway the noise level is 90 dB. Using combined actuator in landing gearwheels will allow decrease negative effect on the environment and eliminate completely the majority of shortcomings. The paper presents the schematic diagram of electromechanical landing gear wheel actuator in which brushless switched-reluctance motors are mounted inside cylindrical gearwheels. Due to low cost materials implementation, small size and weight, low energy consumption and high efficiency maintainability better design and operating characteristics of aircraft landing gear wheel actuator are ensured. While motor-reducer design, specifics of its operation in the landing gear wheel were accounted for. The results of motor-reducer computation, which demonstrated the wide specter of implementation of such kind of actuator for various types of aircraft components, such as landing gear wheels actuators, high-lift devices' elements are given. The presented motor-reducer possesses diversified structural concepts, which allows use it for various types of aircraft both civil and military oriented, as well as for unmanned aerial vehicles (UAV) and spacecraft of various kinds. The prototype of motor-reducer, used for UAV's high-lift devices, displayed its apparent advantage compared to the other actuators, such as design compactability, manufacturability and cost effectiveness. Implementation of the above-described structure will allow fuel consumption saving by both an aircraft, and airfield servicing facilities. The structural concept of the motor-reducer in aircraft landing gear wheel does not have counterparts either in Russia or abroad. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dyul'dina N. E., Nekhoroshev M. V., Pronichev N. D. Developing additive technology of tool electrode manufacturing for aircraft engines parts machining. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 114-120. The paper offers new technological solutions for gas turbine engines (GTE) manufacturing. These solutions are based on special processing methods using and additive technology implementation. To improve technological process of GTE parts manufacturing the authors suggest new technology of polymeric tool electrode (TE) fabrication with subsequent metal coating of its work surface using electrodeposition method. The most complex problem consists in ensuring accuracy of the profiled surface in the process of electrodeposition of a metal layer. The objective of the work is developing computer model of the process of electrodeposition of metal on a dielectric TE for electrochemical machining (ECM). This presented method consists in creating the information model, and studying the main process parameters of electrochemical deposition: electrolyte and electrode surface potentials, electrode reaction behavior, thickness and uniformity of the coating. While analytic model development parameters of electrode reaction, such as the exchange current density; electrochemical anodic and cathodic transfer coefficients; system electrode reaction equilibrium potential were determined. Besides, the above-mentioned method includes comparison of the formed profile with theoretical one. The developed information model demonstrates that the metal coating possesses a variable thickness. On the boundary of cathode with electrode junction a thickening, stipulated by electrochemical processes, was formed. Here, in this zone the thickness deviation of the formed profile from a theoretical one is 355 µm. This implies that a minor mechanical processing is needed. The developed technology allows carry out technological regimes and using the ECM obtain more detailed information on surface shaping. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhukov P. A., Marchenko M. V., Kirillov V. Y. Transition resistance effect on aircraft and spacecraft onboard cable network shielding efficiency. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 121-126. To ensure the specified shielding efficiency electromagnetic screen should be homogenous to the maximum. The uniformity of the shield depends on the resistance between the cable shield, the electrical connector and the onboard device case, i. e. transition resistances. High shielding efficiency can be ensured with small values of transition resistances. The transition resistance is not a constant and can variable significantly during the life cycle of a product. These variations are caused by the effect of various factors: shields and cases bonding and connecting techniques; temperature and environmental conditions; operating conditions. The results of the experiment that simulating a stay in a tropical climate revealed, that the magnitude of the transition resistance has increased up to 8 mOm, and in some cases it increased from 1 to 26 mOm, which significantly exceeds the standard value. While temperature fluctuations effect testing, cable connectors subjected to thermal shock by immersion in liquid nitrogen with subsequent heating to 290°C by the stream of hot air. The results of this experiment demonstrate, that the transition resistance of the heated connector increases from 1 to 6 mOm. In all these experiments, significant changes of transition resistances values in the direction to increase without returning to the initial values were observed. The reason for this consists in the thermal deformation of the parts' shape and contact failure due to the emergence of the oxidized layer. The results of the shielding effectiveness study show that the magnitude of the transition resistance affects significantly the levels of induced interference voltage at the load, connected to the onboard instrument simulator cable. Transient resistance value increasing reduces the onboard cables shielding efficiency. Thus, while electromagnetic shields designing, it is necessary to account for in shielding efficiency decrease on exposure to thermal and climatic factors during the life cycle of the product. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vyshkov Y. D., Reznikov S. B. Supercapacitors applications for aircraft engine start systems. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 127-133. The aircraft engine start fr om standstill to rated idle in ground conditions can be carried out by electric starting gear fed by either onboard or ground-based power sources. The onboard power sources herewith are accumulators, while voltage can be boosted in ground conditions. Accumulators limit the power of electric start systems. Thus, for starting high-power aircraft engines non-electric systems are used. To increase the power of the ground based engine start systems a high-voltage power supplies can be used. The goal of the article consists in demonstrating the possibility of supercapacitors application to start aircraft engine by electric system. As far as a supercapacitor specific power is greater than that of an accumulator, they can be effectively used for increasing the power rating of aircraft engine start electric systems, wh ere accumulators were previously used. Since the energy accumulated in supercapacitor increases with voltage rise, the supercapacitors can be effectively used in higher voltage systems to increase their power. The goal of the presented work consists in studying and comparing characteristics and processes of the starting mode of electric motor, fed by power supply containing supercapacitor and without it, based on the results obtained by computer simulation with Electronic Workbench V5.12. The simulation results confirm the possibility of increasing the aircraft engine start electric system's power by supercapacitor implementation. It means that in many cases it will allow replace aircraft engine start air-compressing and gas turbine systems by electric systems, which possess many advantages and are of great importance for all-electric aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sukhachev K. I., Dorofeev A. S. Development and study of magnetic induction systems for micrometeorites' and cosmic particles' acceleration. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 134-142. This work is dedicated to development of experimental test-bench based on magnetic induction rail system. The test-bench allows the ground testing of spacecraft materials and equipment on resistance to micro particles of natural and artificial origin impacts. It will solve the problems related to the costly and inefficient space experiments, and will significantly increase the repeatability, controllability and frequency of impact experiments. In the long-run this accelerator will be an essential part for developing effective protection of the spacecraft from the meteorite hazard, non-existent at the moment. To solve the problem of low efficiency while converting electrical energy into kinetic energy, which is of great importance for acceleration of small bodies, weighing less than 0.1 g, the authors propose an experimental technique, allowing increasing the efficiency, and, thus, the impactor's maximum speed without increasing the stored energy in storage facilities. The unique feature of the proposed technique consists in increasing the accelerating force acting on the object from external magnetic systems. The authors propose to create a localized external magnetic field directly in the surrounding area of accelerated particles, and then move the magnetization area synchronously with the movement of the accelerated object over the path of the accelerator. This effect is achieved by using multiple-magnetic systems with independent switches and drives, and a single control system. To determine the switching time parameters and parameters of the railguns magnetic systems, the technique of the railgun computation, operating in combination with the multi-loop magnetizing system has been developed. To test the proposed approach a prototype accelerator was designed and developed. The series of experiments confirming the effectiveness of the proposed method was carried out. Experiments were carried out with particles of various masses, a variety of energy storage levels, as well as for several options for magnetizing systems. The upgraded magnetizing system was 23% more efficient than the classic one, with the same energy storage. The developed accelerator allowed obtain the speed of more than 2100 m/s with a total energy of 11.6 kJ stored in the capacitor bank was reached. The authors plan to apply the proposed methodology to the main circuit. According to the simulation results, the main circuit multi-step power supply will also contribute to the efficiency increase of rail accelerators. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bespalov A. V., Petrov A. P., Sokolov A. V. Friction and surface phenomena when stamping hard-deformable alloys. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 179-194. This work considers the issues of friction (dry, boundary, liquid) effect on the hot die forging process. It reveals the main sources of frictional forces formation. High temperatures, pressure and permanent renewal of one of the friction deformable metal surfaces being in the plastic state characterize the external friction during the hot die forging. In the course of stamping, as the die fills, the surface area to body volume ratio is increasing. The destruction of oxide films thereupon on the surface of wrought workpieces and the outcome of the non-oxidized metal particles from them occurs. This event facilitates the development of the forces of intermolecular gripping of the wrought workpiece and the tool. The stainless steel, aluminum and titanium alloys are especially prone to sticking to the tool. Thus, their stamping is always carried out with lubrication. In most cases, the friction at contact surfaces while stamping occurs together with intervening and isolation mediums (oxide scale, oxides, lubricant etc.). Thus, the interaction of lubricants with surface-active substances while stamping becomes of particular importance. The types of lubricants, their composition and the additives effect on the difficult-to-form alloys of low-plasticity processing are considered. The mechanism of action of surface-active substances in conditions of stamping and formation of plasticized surface layer with ultra-fine-grained and nano-sized structure was analyzed. The article analyzed the results of leading Soviet and Russian scientists' studies in the field of nanostructured state forming in the surface layer of the material. Based of the conducted analysis, we can state that the nano-structuring of the workpieces' surface, including pressure shaping, while applying surface-active substances, leads not only to the obtained semi-finished products' mechanical properties substantial improvement, but also to a significant improvement of their technological properties during the subsequent hot deformation, such as stamping. Thus, the compelling for the production possibility of difficult-to-form materials' super-plasticity deformation under lower temperatures and higher speeds of not only volume nano-structured workpieces, but also the workpieces with nano- structured surface is created. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Babin S. V., Fursov A. A., Egorov E. N. The study of intermediate plasma-sprayed layer effect on fiberglass-metal junction strength. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 195-201. The study of laminate composite materials, compounds of dissimilar materials and hybrid composite materials for increasing their strength, fatigue strength and reliability is a topical problem for aircraft building. This work studies the technique for increasing strength of fiberglass with AB-T1 aluminum alloy compound and fatigue strength of hybrid composite material by intermediate layer creation. To reinforce composite compound intermediate rugged porous layer, obtained by plasma-sprayed method. The paper performed comparative analysis, sel ected materials and modes to such layer formation. Fatigue testing of hybrid composites samples was carried out. Temperature effect on shear strength of a composite compound was studied. The effect of fiberglass molding process (with glue or without it) on the components shear strength. As a result of the conducted studies we found that:
The results of the study can be used for new composite materials development and hardening adhesive compounds of dissimilar materials. For example, to develop hybrid composites titanium fiberglass aluminum alloy, and new SIAL variants for fiberglass aircraft propeller blades design, compressor and turbine blades for gas-turbine engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tischenko L. A., Kovalev A. A., Markin A. V. Photoresist thickness selection peculiarities to ensure and improve the lithography process stability during semiconductor devices structures manufacturing. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 202-211. Photolithography is one of the main technological processes for obtaining on a special base a certain topology of various electronic components. The most important thing herewith is minimization of all errors in the course of image transfer fr om a photomask to the photoresist layer, and at the developing stage. In this case the most accurate mage transfer is achieved. The paper is devoted to a topical problem, namely to the photoresist thickness selection specifics to ensure and improve lithography process stability during semiconductor components structures manufacturing. The paper describes the experimental study of the dependence of radiation energy (E0) dose, necessary to full structures' development in photoresist, from the photoresist thickness (h) on the example of SPR700-1.2 photoresist. The energy dose for the structures' full development in photoresist, determining the quantity of energy affecting the photoresist, required for full photoresist elimination from certain areas, determined by components' structures topologies is one of the basic technological parameters of photoresist. In the course of the study one area per each of 33 silicon wafers were detected, wh ere the photoresist was completely removed. Radiation energy, at which the exposure of these areas was carried out, is an energy dose, necessary for the full structures' development in photoresist. Thus, the plot of energy dose, necessary for full structure development, versus photoresist thickness was obtained In the course of mathematical calculation, approximation of experimental harmonic dependence was performed and equation of the given curve was obtained. Rational operating points (thickness) were determined using the plot obtained while experimental curve approximation. These points represent extremums, since with minimum deviation from the rated value, inherent to the considered operating point, the energy dose for full structure development in photoresist would vary insignificantly. Thus, nine operating points corresponding to a certain photoresist thickness were obtained as the result of the approximated curve analysis. The result of experimental study of radiation energy dose dependence from photoresist thickness described in this paper consists in obtaining of a number of recommended photoresist thicknesses, which observing can lead to the most accurate image transfer from photomask to photoresist layer, which, in its turn, will improve lithography process stability during semiconductor components structures manufacturing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pokrovskii A. M., Chermoshentseva A. S. Experimental study of nano-additives effect on properties of composite materials with interlayer defects. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 212-221. The subject of researh in the presented paper are interlayer deffects in composite materials (CM), prevention of the rate of their occurrence by strengthening the compoistes with nano-sized powder. It contributes to safety increase while aircraft operatioin and allows prevent emergency situations duting flights. The goal of the studies consists in developing methods for manufacturing techmology of samples made of epoxy resin reinforcement of laminated CMs with interlayer defects and nano-dispersed powder, by adding nano-particles to the binder, and obtain maximum degrees of CM filling with nano-sized powder. In the process of performing this work the experimental samples were produced, and the series of tests were conducted. It is noted that occurrence of interlayer defects contributes to lifespan reductiono of a product made of composite materials. The analysis was performed, thereby, on determining the character of a delamination type defects growth. The properties such as mechanical characteristics anisotropy and the possibility of hidden defects presence in the form of material discontinuity over the separation surface are intrinsic specific properties of composite materials. The paper presents the experimental results of the study how degree of filling of the ED-22 resin by nano-sized silicon dioxide powder (“Taroksil” T-20) of various concentration affects the mechanical properties of a heterogene material. A brief description of production process technology of samples, made of epoxy resin and nano-disperced powder, is presented. The above said studies are used for solving the problem of interlayer defects hardening in laminated composiste materials, which occurrence is a consequence of the aircraft parts production technology imperfection and effect of operational loads of aircraft, by adding the nanoparticles to the binder. The optimal degrees of CMs filling by nano-sized dioxide silicon powder in dependence of mass concentrarion were found. The testing results of the samples made of CM with embedded interlayer defects with adding nano-dispersed additives with various volume concentration from 0.1% to 0.5% to the binder are presented. These tests tresults' data would be offered for implementation by the enterprises of Holding JSC “Helicopters of Russia”. The work is prospective for further consideration and implementation in the future research activities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balyasov Y. A. Production management in conditions of multiproduct single-part and short-run production. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 222-227. The scope of the article is production monitoring system developing at the machine-building enterprise in conditions of single-part and short-run production, allowing data provision of production progress, contribution to managerial decisions effectiveness increase and production lead-time reduction. This goal implies organization of a production processes information system at the enterprise that accumulates initial order information, such as engineering and design documentation, route technological processes, operational labor standards. This data allows calculate a period of execution of works (with account for product structure) and draw an activity network as the basis for the day-to-day production planning. Actual production data is fixed in the strategic points relating to such production stages as resource supply, mechanical processing, finished items transfer to the picking store and to further assembly process. Analytical comparison of the initial and actual data serves as the basis for the management decision-making concerning de-bottlenecking and can be used in production scheduling. It is supposed to use two groups of Key Performance Indicators (KPI) of production activity that characterize: – the conformity of production progress with planned, estimated and directive periods of execution of entire work as well as intermediate production stages; – production volume expressed in terms of production lots quantity or standard hours of work that makes it possible to estimate the current and coming labor content as well as production continuousness. The key feature of the procedure is that all the data necessary for the monitoring is formed automatically with execution of standard working functions of a person responsible for their execution, disposing of the difficulty to obtain additional manpower resources. This system serves as the basis for the production processes operative monitoring adapted to the single-part and short-run environment. It allows: – systematize and analyze the real-time data on the basis of measurement of the strategic points that specify the execution of order; – control the process on every level, from foreman to general manager; – estimate the planned machine utilization. This technology of production data organization is implemented at the DB “Armatura”-branch of FSUE “Khrunichev SRPSC”; the day-to-day production planning and monitoring algorithms are being tested. As a result of the partial implementation of the procedure there is a tendency to reducing of the throughput time. The suggested technology can be used at manufacturing enterprises with a high level of experimental development, such as engineering departments with a pilot plant. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Motyreva E. E., Tarasova E. V. Hedging of financial risks of developing enterprises. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 228-235. Nowadays developing enterprises undergo hardship to find sources for innovative projects financing. Investors do not want to invest in risky programs, while enterprises are no able to bear the financial risks themselves. A distinctive feature of the high-tech defense developments production financing is preferential financing at the expense of budgetary funds. However, that does not absolve enterprises from financial risks due to insufficient financing or failure of terms. In this case, the enterprise is better to involve extra-budgetary financing. It would help: to exclude cases of forced attraction of own funds; to increase profitability and avoid loss of development; to reduce the probability of disruption in terms and penalties; to release a part of the developer's funds for own technical re-equipment and development; to reduce the impact of design, technological, financial and economic risks. One of the distinguishing features of the development of high technology products is the presence of the objects of exclusive rights. These objects have a certain value, depending on the area of their application, utility, degree of elaboration and novelty. Additional funds for innovative projects implementation may be attracted by the sale of options for these objects to interested parties. For the purposes of the developing company, it is necessary to sell such a number of options and at such a price that it would be able to ensure a risk-free return (i = 25%). For the company acquiring the option, the price is defined as the present value of future benefits taking into account the likelihood of a favorable outcome. Including the price of sold options in the financial model of the project, you can achieve its payback. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tikhonov G. V. Methodology for russia's small and medium-sized enterprises adaptation to crisis conditions. Aerospace MAI Journal, 2017, vol. 24, no 3, pp. 236-240. In modern conditions of the Russian economy and restructuring of certain industries, the significance of enterprises’ management increases. It is stipulated by the disruption of a great number of economic ties, active import substitution of products manufactured by certain industries, as well as the necessity for significant breakthrough in the field of military industrial complex (MIC). Instability of external environment with high risks level is aggravated with account for the challenges facing the Russian industry in conditions of scale sanctions. In this connection, the role of small and medium-scale enterprises, which significance in the modern world is steadily growing in both developed and developing countries, is increasing. Methodology for assessing and monitoring industrial enterprises' adaptation level to the crisis conditions is analyzed in real conditions. Monitoring system of adaptation level of separate enterprises to crisis conditions is an important element of anti-crisis policy, since it should contribute to the selection of the strategically important business-partners selection, subcontractors on production activities, etc. The enterprises with high-level adaptation to the crisis conditions should be primarily included in industry plans while preparing and implementation of the products critical for the industry. The relevance of small and medium-size enterprises adaptation process is associated with the fact that their ordering parties are large enterprises. So operations of “business for business” (b2b) type are implemented. Thus, small and medium-sized industrial enterprises in most cases are not oriented on individual consumers, but on a big business, which establishes its own rules of conduct on the market. The area for the study is steady development mechanism of economy of industries, complexes and enterprises. The object of the work is the Russian small and medium-sized industrial enterprises overcoming the crisis phenomena in the economy. The subject of this work is methodical and practical approaches to the Russia's industrial enterprises adaptation to negative conditions in the economy, including the assessment of the adaptation level of the enterprises. The aim of this work consists in developing a methodology of Russia's small and medium-sized industrial enterprises adaptation to the conditions of crisis. The methodological basis of this work is a systematic approach to the small and medium-size enterprises adaptation assessment to crisis conditions. Practical significance is determined by a comprehensive quantitative approach to the assessment of industrial enterprises' adaptation level to the crisis phenomena in the economy. In theoretical terms, the overall conclusions on the adaptability of economic systems can be formulated:
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Belov G. O., Stadnik D. M. Gear-type pump design procedure development providing its dynamic loading reduction. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 7-14. Aerospace hydraulic systems generate pressure and flow-rate oscillations in the course of their operation, which in its turn leads to vibrations and noise level increase. Thus, the problems of the study can be formulated as follows:
The authors realized numeric model with allowance for the two-phase nature of the flow and the pump's design features using programming language Delphi. Computations allowed obtain the fuel consumption patterns at the input and output of the pump, as well as cavitation phenomenon in the locked volume. Based on computation results, a technique for balancing grooves in front foot bearing was developed. The effectiveness of such changes in construction was demonstrated experimentally at the Institute of Machine Acoustics. Using scada system LMS Mobile the authors fixated reduction of vibration, pressure oscillations and noise for NMSh-5-25-4 pump. Thus, all the planned tasks of the research were fulfilled. The results of this work were implemented at Wroclaw technical university (Wroclaw, Poland) and Institute of Machine Acoustics (Samara, Russia). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komissarenko A. I., Kuznetsov V. M., Simakov S. Y., Muraschev A. A. Meteorological rocket “MERA”. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 15-23. Rockets MMP-06 and MMP-06M are nowadays are the most popular rockets in Russia, while the “Dart” system is the most popular rocket in the USA. The MMP-06M reentry vehicle maximum flight altitude is 60-80 kilometers. Since 1988 the rocket is employed for the wind velocity and temperature measurement in upper atmosphere. The rocket is equipped with the engine with a steel body as a thruster, which results in low thrusted efficiency for modern technology state-of-the-art (the empty engine with stabilizers to fuel weight ratio equals 0.56). The altitude of probing is relatively low, and equals 80 km, and probing at the flight upward trajectory is impossible. To avoid the above-mentioned drawbacks, the SC Instrumentation Design Bureau under contract with the Ministry of Environmental Monitoring and Research Developed “Mera” meteorological rocket with probing altitude greater than 100 km. To serve as a thruster the surface-to-air bi-caliber missile engine, using solid propellant (with density impulse of 240 kgFs/kg) was developed and finished-off, with fiberglass body and the empty engine with stabilizers to fuel weight ratio of 0.3. It allows significantly reduce initial weight of the rocket and its size. The meteorological rocket “Mera” was designed based on the above said surface-to-air bi-caliber missile engine, and MMP-06M “Dart” as reentry vehicle cruise component. To provide requirements fulfillment (achieving altitudes over 100 km) meteorological rocket “Mera” has two-stage structure with passive cruise component and equipped with a booster. Measuring and servicing equipment is allocated in the cruise component in the form of a container. The cruise component is equipped with parachute in a separate container. On the assumption of stiffness conditions and required temperature the body of the cruise component is protected by combined coating. To ensure radio signal of the equipment propagation the cruise component is equipped with radio-transparent insertion. To ensure aerodynamic stability the cruise component is equipped with asymmetrical consoles. The paper presents aerodynamic, weight, inertial and ballistic characteristics, impact zones and separated engine trajectories, as well as cruise component impact zones. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dukhopel'nikov D. V., Vorob'ev E. V., Ivakhnenko S. G. Ion flux control in hall accelerators. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 24-30. Hall thrusters are widely used for satellite orbit correction and marching operations for altitude change. At the same time the accelerators designed according to similar schemes acquired wide spread occurrence in vacuum ion plasma technologies as ion-cleaning and nano-scale surface treatment systems. In a first approximation, in the design of such devices it is assumed that the magnetic field does not affect the ions movement in the accelerating channel. Actually, the ions deflected slightly in azimuthal direction under magnetic field impact, whereby the beam acquires the shape of one-sheet hyperboloid. With the thrusters, it might lead to the plume spread, derating and angular momentum occurrence. This leads to significant divergence of the ion beam in the technological accelerators operating on relatively lightweight argon. For surface cleaning before coating deposition such divergence of circular beam is acceptable, since maximum processing area is required. However, for dimensional ion beam processing narrow ion beams with Gauss ion current density distribution are required. At the same time, effect of the ion azimuthal deviation does not allow focusing the ion beam of the Hall accelerator only by coning the walls of the acceleration channel. In this paper, additional magnetic pole was installed for focusing ion beam into a spot with Gauss ion current density distribution along radius at the outlet of the cone acceleration channel of the ion source. This magnet pole produced the magnetic field which vector is opposed to magnetic field vector in the channel. Ion beam in the additional magnetic pole area turns in azimuthal direction, opposite to its turn in the acceleration chamber. As a result, the beam is coned and focused at a specified distance into a spot with maximum ion current density concentrated in the center. The paper formulates the criterion of optimum ion beam focusing in accelerator with anode layer. The ion current density distribution along the radius of the focused ion beam was measured with the accelerator experimental sample. It was shown that the installation of additional magnetic pole allows focusing the ion beam completely. The obtained results can be used in the design of ion sources for punctual ion-beam machining of the details for optical and electronic industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezrokhi Y. A., Kalenskii S. M., Morzeeva T. A., Kizeev I. S. Distributed power-plant concept with gas drive of external fan module analysis. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 31-41. The paper analyzes the concept of distributed power plant (DPP) for prospective long haul passenger aircraft. This DPP is intended to provide deeper integration of a power plant and an aircraft, as well as increase its fuel efficiency. Possible variants of drive realization for external fan modules, as a constituent part of the distributed DPP, are presented. The necessity of considering the gas drive, realized by introducing an additional transient duct between the turbine of dual-flow turbojet engine and the turbine of the external fan. The paper presents the preliminary analysis of DPP with gas drive of an external fan module developing possibility in the simplest for realization version incorporating a single external module. The authors developed the technique for numerical study, carried out the evaluation of the specified DPP parameters under various values of total pressure losses in the transient duct to the external fan module and performed preliminary evaluation of the distributed power plant weight. Further development of the considered distributed power-plant concept the additional gas heating in the transient duct while the take-off mode is offered. Additional calculations of new type engines are carried out, and estimation of new distributed power-plant structure parameters improvement possibilities is made. In conclusion, comparison of the considered distributed power plant structures basic parameters at various degree of total pressure losses in the transient gas duct to the turbine of the external fan module is presented. The conclusion is drawn on the necessity to assign transient ducts and intermediate heating systems technologies to critical category. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I., Kochetkov Y. M., Zenin E. S. Determination of thrust specific impulse losses occurring due to chemical non-equilibrium in aircraft power plant. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 42-49. As usual, thermodynamics and statistical mechanics deal with the problems, which suppose a system to be in equilibrium. Thus, the implemented mathematical tools could be rather conditional in cases of the systems with irreversible chemical reactions, as well as gas flows with thermodynamic non-equilibrium. Depending on how the system differs fr om equilibrium state, the great majority of practical solutions of combustion problems referenced in classical literature this condition is observed. In contrary cases, i. e. significant non-equilibrium in combustion in high-speed flows problems, and detonation in particular, the variation fr om stationary proliferation of chemical reaction fronts is unreasonably neglected. The traditional combustion in gas flows problem statement is unidimensional and based on consumption, momentum and energy conservation laws. Effects of viscosity force and thermal conduction are accounted for herewith. The basic difference of idealization consists in supposition of consistency and averaging of thermal capacitance value under constant pressure and volume. However, these values are dependent from chemical components composition and temperature in particular. Viscosity factor and other factors, characterizing transition are also functions of gas mixtures composition and temperature. As a consequence, gas constant and constitutive equation differ significantly from the idealized form. For complete analytical description of combustion gas dynamics, accounting for mutual diffusion of chemical components, regularities of components vanishing and occurring of new ones, as well as evaluation of total heat emission due to the completion of chemical reactions are required. Systematic numerical studies of homogeneous and heterogeneous chemically non-equilibrium gas flows in aircraft power station nozzles are already conducted for many years. Various authors obtained results for combustion products of a number of fuels employed in aviation and rocketry. However, calculations of such flows do not satisfy modern practical requirements in all respects. Their main disadvantage consists in orientation on strictly defined set of substances and chemical reactions. To other shortcomings are neglecting the small concentrations of the reacting components, which compels to coarsen recombination mechanism. The variety of propulsion installations designs predetermines the presence of various units with non-equilibrium combustion in the area of lean and reach mixtures, such as gas generators; liquid rocket engines combustion chambers with complex mixture-formation systems; a number of pressurization systems and gas passages with gas flows; combustion chambers and afterburners of air-jet engines. To a certain extent, determination of specific impulse losses in rocket solid engines due to chemical non-equilibrium with allowance for its effect on formation of Al2O3 and ALN condensed particles presents practical interest. The nowadays reality is the study of combustion detonation mode, wherein flows idealization is unjustified due to high conversion rates, and chemical reactions are principally non-equilibrium. The paper presents gas flows with non-equilibrium chemical reactions modeling in the form of conservation equations: uniformity of energy and impulses, wh ere impulses are presented as a product of gas mixtures density scalar and their velocity vector. As a result, in addition to the equation in Navier-Stokes form the authors obtained one more member, accounting for relaxation processes in thermodynamic system. Based on carried out analysis of the law of mass action the authors obtained interrelation between Gibbs thermodynamic potential with the equation member, accounting for non-equilibrium in gas flows with specified content in the form of normalized function. Based on it, the authors offer an engineering design procedure of a rocket engine specific thrust losses (aircraft power plant) caused by chemical non-equilibrium. The values of combustion products equilibrium and frozen compositions for the specified fuels are used for computation of adiabatic coefficients for lim it cases and normalized function. The paper presents graphs illustrating the computations for a wide spectrum of combustion products compositions. The examples of computation results of specific impulse for various cross sections of rocket engines nozzles. The engineering method for calculation of the thrust specific impulse losses occurring due to chemical non-equilibrium allows estimate adequately their contribution to the common share of losses. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Orlov M. Y., Anisimov V. M. Computational study of compressor operation mode effect on gas turbine engine combustion chamber processes. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 50-56. Improvement of modern GTE and power plants directly related to improvement of the combustion chamber. However, combustion chamber is one of the most problematic parts in terms of the design and finishing-out. To solve these problems the authors developed the technique for performing common computations of the compressor and combustion chamber together. In the framework of this work this method was used studying the effect of flow unevenness, occurring behind the compressor blades, and on combustion chamber workflow. The method has been further developed in the way of implementation of common mesh model for the compressor, the combustor, and working out the boundary conditions setting principles. Geometrical model consists of four different geometrical volumes: guide vanes of the penultimate stage of high-pressure compressor, the impeller and guide vanes of the last stage and the flow path of combustion chamber. The sector of compressor and combustor was used instead of full-sized model to reduce calculation time. The sector angle kept constant for compressor and combustor. Three-dimensional modeling software package Ansys Fluent was used for simulation of common operation of compressor and combustion chamber, since the combustion processes simulation was tested and verified for this package. Mathematical model and boundary conditions were set after mesh generation. Mathematical model included different calculative models, which were necessary for the combustion simulation. Boundary conditions were specified by temperature and pressure of the flow at the inlet and of the fuel. The flow blows the guide vanes at a certain angle. Hence, the direction vectors were set in cylindrical coordinates. The simulation was carried out in non-stationary arrangement. Thus, the certain time step and number of time steps, which are necessary for convergence, were set. The simulations were carried out for three engine operation modes (nominal, 0.7 of nominal and 0.5 of nominal regimes) with and without compressor. The least effect of the compressor detected at the the engine nominal mode, and the the largest was detected at 0.5 of the nominal. The obtained results were compared with the results from simulation without compressor. Simulations revealed that that blade wakes extend up to the flame tube head. These wakes change the flame tongue, pressure field, temperature and velocity in the recirculation-mixing zone. It can affect combustion efficiency, ecological performance and temperature field at the combustor outlet. Thus, the simulations, which accounted for combustion chamber and compressor, more fully represent the characteristics of the working process of the combustion chamber and increase the efficiency of new products design. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baklanov A. V. Low-emission combustion chamber of diffusion type employing micro flame burning process for converted aircraft gas turbine engine. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 57-68. Combustion of fossil fuel is accompanied by a number of toxic agents' formation. Nitrogen oxide and carbon monoxide are the most ecologically destructive, for they hurtfully affect humans and the environment. For these reasons the paper solves the topical problem on creating a diffusion combustion chamber for a converted aircraft gas turbine. For the purpose of efficient aircraft engine combustion chamber conversion from fluid to gaseous fuel, the author proposes the combustion chamber design and complex approach, including of engineering and design studies and experimental studies. The experimental method includes three stages. At the first stage, the butners' outlet parameters are defined. For this purpose, a workbench for determining a burner throughput capacity and obtaining concentration pattern of the air-fuel mixture in swirling jet burner outlet. CO2 was used as a gas fed to the fuel ducts, instead of methane. Concentrations distribution over the sections after the burner presents the pattern, allowing trace the CO2 concentration level variation dynamics in whole area of measurements and in each point of the swirling jet. It allows evaluate the quality of air-fuel mixture preparation. The burner throughput capacity was evaluated at various pressure differences. Based on the performed work, selection of the burner geometry for implementation in the compustion chamber was performed. While implementation of the flame tube head with a large number of atomizers, fuel distribution uniformity ensuring is of especial importance. It provides stable combustion process and mixture homogeneity at the combustion zone inlet. To determine the flame tube head flowrate characteristics, an installation with compressed air delivered to fuel ducts was implemented. Evaluation of air throughput deviation from its average value was carried out. It allowed working out the flame tube head from fuel feed ducts dimensions' optimization viewpoint. The next stage consists in working with a full size combustion chamber. This stage includes two trends. The first one is the pressure loss determination in the combustion chamber, while the second one is determination of the non-uniformity of the outlet temperature field. Selection of combustor can degree of opening and air distribution along its length to provide optimal pressure losses and temperature field. At the final stage the combustion chamber as a part of the engine functioning test was carried out. The engine throttle performance characterization and measuring the exhaust emissions of the engine was performed. In accordance with the results of the studies, conclusions were made that the realized complex approach to toxic agents emission reduction allowed design the combustion chamber reducing nitrogen oxide emission by 40% and carbon oxides by 20% compared to a stock combustion chamber. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharov I. V., Trubnikov A. A., Reshetnikov D. A. Functional control software/hardware complex master side model. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 69-78. With implementation of existing methodological support of regular automated verification systems (AVS) the state and performance of a short-range missile of air-to-air class (AAM SRM) control system sensors are unobservable. Thus, while regular AVS typical control algorithms realization technical state of control system sensors, such as linear accelerometers (LA), or angular accelerometers (AA) can be estimated through indirect parameters, without their basic parameters determination (transfer factor, etc.). This could significantly reduce methodological fidelity of guidance system control. To solve the above said problem the authors offer implementation of functional control (FC) method. This method can be realized based on software/hardware complex (SHC). The paper suggests scientific basics of functional control. They are stipulated by implementation of harmonic balance of automated control theory. The FC structure, organized by duplication method, was used to realize AAM SRM guidance system FC control sensors. To minimize the control structure dimensionality at the inputs a single primary impact on the missile guidance system is applied using harmonic oscillation workbench (HOW). To close FC links one should be aware of HOW functioning as a master side of SHC. HOW is the main preset part of SHC, generating a single primary stimulating effect on the missile during FC of its guidance system sensors. To close FC system it is necessary to set correct stimulating action on an FC object. It is necessary herewith to eliminate FC resonant mode, and ensure FC main sensors functioning in linear range, i. e. exclude: guidance system signals overload limiting for LAs; missile body spin velocity limiting for AA detection unit, as well as angular target tracking rate and locating angle limiting for target-seeking head (TSH). To ensure harmonic oscillation “comfort mode” for the missile guidance system, selection and adjustment of HOSs design values is carried out. For this purpose, the developed SHC FC master side model is used. In addition, the developed model is used for characterization of secondary stimulating effects on HOW, LA and AA detection units and determination of the signals of their reactions. The process of HOW operation can be represented by a certain model in Laplace operator form. This model includes oscillating and measuring loops. The oscillating circuit dynamic model represents an oscillating link with time constant and damping factor, as well as nonlinearity of saturation type with known parameters, stipulated by HOW design specifics. Measuring loop includes axial power transmission (PT) and inertia-free angular sensor. PT is free of reduction elements, and its gain KPT = 1. The conducted experiments on a certain HOW embodiment confirmed the adequacy and performance capacity the developed models of SHC FC master side, as well as correctness of the HOW design values, allowing eliminate AAM SRM guidance system's signals limiting and their termination to stop. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Al'bokrinova A. S., Grumondz V. T. Gliding unmanned aerial vehicle flight dynamics at low speed and launch altitudes. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 79-85. The authors conduct studies of gliding unmanned flying vehicle (UAV) flight dynamics at low speed and launch altitude. In the case under consideration the UAV flight dynamics significantly depend on initial flight speed and initial flight altitude which determine the total UAV energy and, as consequence, UAV's dynamic capacity while moving along the trajectory. The paper considers the following two problems:
We assume the UAV is equipped with a certain booster engine with fixed total impulse, which can be realized by various thrust variation functions in the course of UAV movement. Much attention was paid to the study of launching conditions and thrust behavior at the initial trajectory portion impact on the flight range under gross thrust impulse limitation, as well as studying of various possible technological deviations of thrust vector direction from UAV axis of roll impact on movement stability and UAV launching safety. The last problem was considered in the form of the following two problems:
We assume that the UAV is launched in undisturbed air conditions so that at the starting moment it is not subjected to the additional aerodynamic impact, while the carrier is moving at constant altitude with constant speed. The authors developed a mathematical model of UAV spatial motion all over the flight. The control system accounts for pitch angle and angular velocity deviations. Solid fuel accelerator with fixed thrust impulse value, variable thrust value and operating time is considered as a boost engine. A time of engine ignition was computed. Movement parameters at the initial trajectory segment, booster thrust variation functions impact on the flight range and booster thrust misalignment impact on the UAV movement parameters and stabilization were evaluated. Extreme (guaranteed) values of solid fuel booster thrust misalignment caused by technological errors while booster manufacturing and mounting on the UAV ensuring the UAV flight safety at two stages – controlled flight without thrust and controlled flight with operating booster were obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zaichik L. E., Desyatnik P. A., Zhelonkin V. I., Zhelonkin M. V., Tkachenko O. I., Yashin Y. P. Mobility effect of flight simulator cabin on aircraft in-flight refueling problem modeling. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 86-94. One of the serious problems of flight simulation with flight simulators consists in reproduction of accelerations experienced by a pilot while in flight, which play an important role in piloting. The paper considers this problem in the context of aircraft in-flight refueling. The goal of the study is quality estimation of cabin movability over various degrees of freedom effect on piloting, pilots nature of action and his judgement on simulated accelerations degree of adequacy to real flying conditions. Experiments were conducted with TsAGI PSPK-102 flight simulator containing cabin with six degree- of-freedom mobility, collimated visualization system, instrument display, side-stick control with electrical loading system, and thrust control levers. The authors developed the in-flight refueling task simulation technique using flight simulator with movable cabin. The problem of cabin mobility system control algorithms optimization was fulfilled for the considered task. The pilot's task consisted in performing closing-in with the refueling tanker and carry out the refueling cone in the course of the flight. Experiments were conducted with participation of an Honored military pilot, who had wide practical experience of refueling tasks in real flight conditions. Experimental data on the accelerations effect on unbiased indicators of the cone tracking accuracy, pilots actions characteristics and aircraft movement parameters were obtained. The study demonstrates that reproduction of accelerations affecting a pilot significantly increases the adequacy of in-flight refueling problem simulation to a real flight. According to the pilot's, opinion axial accelerations exert the strongest effect on refueling task. Nevertheless, reproduction of vertical and lateral accelerations in the course of flight simulation plays an important role as well. The obtained objective data and the pilot's opinion accord well with overloads and angular accelerations over various degrees of freedom significance analysis performed based on earlier developed theoretical approach to the accelerations impact on piloting. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tischenko L. A., Kovalev A. A., Chizhikov S. V. Basic process operations parameters impact of silicon electronic lens manufacturing and its storage conditions effect on electron beam shape studying. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 95-103. Lithographic processing is one of the key operations of technological processes while semiconductor devices' and integrated circuits manufacturing. Its parameters effect strongly the precision of the devices structure creation, and, as a consequence, its output characteristics. Multi beam lithography is implemented in particular. Its technological equipment uses silicon electronic lenses for electron beam control, which electronic and optical parameters affect the accuracy of the manufactured product structure and, as consequence, their output characteristics. The paper tackles the topical problem of ensuring the specified electro-optical parameters of electrostatic lens (including geometric sectional shape of electron beam) during its production, storage, and transportation, as well as repeatability of these parameters from batch to batch. The research object of this project is electro-static lens representing silicon plate with a plenty of holes of circular shape. The lens under study is used in technological equipment for multi-beam e-lithography for a powerful beam splitting into a multitude of beams. The electro-static lens parameters degradation causes in length of time identification, and their elimination technique development are the main tasks of this studies. In the course of the study, a number of operations and factors that could affect the electro-optical lens parameters was revealed. According to the results of expert evaluation of electronic lens manufacturing technological process, these factors are oxidation and chemical cleaning operations. The results of various technological operations and factors effect on electro-optical lens parameters variation were presented. While this research a series of experiments was conducted, which considered variation of electro-optical lens parameters in length of time. The obtained results of the studies allowed revealing possible reasons of electro-static lens parameters degradation in length of time, and developing technological recommendations to prevent this degradation. The plan of future studies is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tamarkin M. A., Verchenko A. V., Kishko A. A. Heavy-plate materials waterjet cutting effectiveness improvement. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 104-114. A voluminous assortment of parts, characterized by higher requirements to accuracy and reliability, is used while aircraft manufacturing. They are fabricated fr om various materials, such as steel, aluminum, plastics and composites. Special attention is payed to developing new methods of the parts manufacturing and improvement of conventional technologies. The majority of the parts is produced by pattern cutting of various materials of 0.5 to 200 mm thickness, followed by their machining or without it. It is interlinked with the development of CNC metalworking Machinery Park, where forged pieces or form workpieces are used in increasing frequency. The main question consists in productivity and quality of cutting blanks. There is a great variety of pattern cutting methods, distinguished by productivity and principles, with peculiar advantages and disadvantages. The authors consider the hydro-abrasive cutting, which is the newest and prospective metal cutting methods. Hydro-abrasive cutting is the most up-to-date and efficient method for obtaining either blanks or parts from plate aviation materials. The cutting process is carried out by the thin water jet with abrasive grains mixture, emitted at high (supersonic) speed under high pressure up to 6000 bar. Garnet sand with 7.5-8 hardness is used as an abrasive material. The process represents erosion destruction under impact of working jet, wh ere the abrasive cuts the chips microlayers, while water takes them away from the cutting zone. The main advantages of hydro-abrasive cutting are high productivity ensured for high cutting speed (steel up to 300 mm), the absence of residual strains at the cut edge, the possibility of cutting practically any metal and non-metal as well as the ability of cutting figured profile and irregular shape parts. Nowadays the process of hydro-abrasive cutting is poorly studied. Theoretical dependencies accounting for all technological parameters effects for the cut ruggedness and corrugation determination, and dependencies reflecting the value of cutting jet lagging. The quality of hydro-abrasive cutting depends on the feed rate, the thickness and type of cutting material. It was found, that feed increase reduces the quality of cutting, increases ruggedness, and the area of smooth cutting reduces, while the corrugation and obliquity of the cut increases. Deffects caused by jet lag cutting, such as formation of a burr on the sharp outer corners, forming holes in the inner corners, overcut and undercut at the beginning of the cut are also found. The goal of this study was to explore the effect hydro-abrasive cutting modes, namely the feed effect on the cut roughness. After a row of experiments the samples made of three different materials with 30 mm thickness, namely, steel 30HGSA, aluminum D16, multi-layer polymer composite such as titanium-fiberglass were obtained. When cutting the feed was changed stepwise from 5 mm/min to 120 mm/min for a sample of steel, to 200 mm/min for samples of D16, and to 160 mm/min for a sample of the composite. The ruggedness of these samples was measured at the specific areas of the cutting section. Analysis of ruggedness dynamics allowed suggest a mathematical model of cutting surface ruggedness profile forming. The ruggedness is formed by free abrasives, which remove repeatedly the micro-chip layers. The mathematical model is proved by experimental data, as indicated by a graph of the cutting ruggedness dependence from the cutting head feed. The experimental data and theoretical curves allow predict the cut quality of the hydro-abrasive cutting. Based on this data, the possibility arises to select the most optimal hydro-abrasive cutting mode cutting, or a certain type of defects elimination. The cutting rate optimization is possible by slowing down the feed in areas of defects formation, or ruggedness unevenness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Belov O. A., Berdnikova N. A., Babkin A. V., Kozlov M. V., Belov D. A. Composite shape-generating tool set for spacecraft antennae reflector manufacturing. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 115-122. Irregular shape items manufacturing from polymeric composite materials (PCM) requires the tool set, which geometry duplicates geometry of the item. The material is spread on the shape-generating tool set, and then its polymerization is carried out at the predetermined pressure and temperature that can achieve up to 200°C. In this respect, the most complicated problem while forming precision items from PCM consists in temperature deformation occurrence while polymerization process. For years, metal hybrid tool sets have prevailed in high-precision composite parts manufacturing. A hybrid tool set has invar (nickel alloy with CLTE close to zero) shaping plate and a support structure made of some other metal with sufficient thermal conductivity. The tool set of such kind involves shape-generating plate attachment to the support structure means, which ensure the possibility of their free thermal extension. The drawback of metal tool sets consists in their high cost, low material utilisation ratio and long manufacturing cycle. The next step in tool sets for high-precision items made of PCM evolution was creation of composite shape-generating tool sets. Fiberglass and carbon reinforced plastics are implemented for such tool set manufacturing. Its surface can be coated with ceramic or gel coat layer of precise thickness, providing minimum roughness, maintainability, and increasing the items takeoffs. Composite tool sets does not have disadvantages of their metal counterparts, though several design problems are still stay unsolved. This paper proposes a carbon composite tool set design for satellite antenna reflector producing. The main requirements to this tool set are precision and stability of the shaping surface. Design solutions are validated by thermal and static mechanical analyses based on finite elements method. In addition, the paper presents the results of autoclave operation simulation, which allows analysing the tool set optimal positioning inside the autoclave to provide uniform heating. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shmidt I. A., Bormalev S. V., Mekhonoshin K. A. The concept of managing configuration and organization of technological preparation for assembly production of aircraft engines. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 123-131. Aircraft engines manufacturers face the following challenge: on the one hand to ensuring the product configuration management, and, on the other hand, the necessity of effectively employing financial, material and human resources throughout the entire aircraft engine life cycle. This problem can be fixed due to information support of aircraft aviation engines' life cycle based on software solutions such as Product Lifecycle Management (PLM) and Enterprise Resource Planning (ERP). The aircraft engine building branch intensively employs PLM solutions developed by Siemens PLM Software at the stage of design documentation development. aircraft engines design is carried out with allowance for the methodology of 3D electronic model design (EMD) of a product with NX system under control of PLM-system TEAMCENTER. PLM solutions are not used at the stage of the technological preparation for assembly production. The technological preparation process is oriented on implementation of paper design and technological documentation. The existing process does not link the stages of design and technological documentation development. At the stage of technological preparation of production process, the electronic structure of the product is practically never used. The technological preparation and configuration management systems depend largely on the human factor. The production planning system is not working effectively due to the absence of connection with technological regulations and assembly production process. The product assembly efficiency can be improved by creating a unified information environment for developing design and technological documentation. The TEAMCENTER PLM system implementation for technological preparation of aircraft engine assembly production will allow develop a unified information environment for developing the design and technological documentation. It will enable also the product's configuration management problem fixing and reducing time and costs associated with aircraft engines. A key feature of the new business process is the TEAMCENTER system implementation at all stages of production technological process preparation, and the products configuration and assembly are carried out according to electronic technological structure and technological process using 3D visualization and step-by-step account of assembly process. Technological structure of the product will allow fixing the problem of production configuration management throughout assembling process. The technological structure data should be transferred to EPR system of production planning. The equipment and assembly must be carried out via the MBOM and technological process using the three-dimensional visualization and operational accounting of assembly production process. The operational account will allow monitoring the production progress and providing feedback to the production planning system. The step-by-step account will ensure documenting of the product configuration requirements carrying out and forming actual product configuration. Introduction of the TEAMCENTER PLM system while preparing the assembly production will allow solving the configuration management problem. Formation of actual configuration will provide a solution to the product configuration control problem, such as documentation, identification, and traceability of the requirements compliance status to products at all product assembly stages. Implementation of the 3D product models facilitates understanding of new products design, allows exclude drawing working documentation to automate the technical documentation development process and, as a result, reduce the time of assembly and manufacturing costs. Developing a unified information environment for design and technological documentation preparation via the PLM TEAMCENTER system will provide the market launch of new products with the specified characteristics in the shortest possible time and at the lowest cost. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gabrelyan A. S., Ivanov N. S., Kondrashov D. A., Korenchuk K. Y. Superconducting electric motor with stator ring winding. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 132-140. One of the promising trend of modern transportation systems development is transition to electric propulsion. This is topical for aircraft industry too. However, to solve this problem it is necessary to design electric motors with high power density over 20 kW/kg. To achieve such figures of the specific power is possible only using cryogenic cooling, and modern superconducting materials. Design of the electric motors with superconducting inductor and armature windings, will allow obtain maximum benefits in terms of weight and size. This relates to the possibility of increasing the magnetic induction value in the motor air gap, as well as with the stator linear load increase. Design a fully superconducting electric motors is complicated by the absence of any universal computation methods, as well as a number of design features and the critical parameters of high temperature superconducting tapes nonlinearity. All this requires the development of new computation methods for such kind electric motors. The paper presents a fully superconducting electric motor with a ring armature winding and the method of determining the its specific power and the results of finite element modeling in three-dimensional formulation. The obtained analytical expression for the main magnetic flux allows derive an equation for the power density of HTS machines with annular armature winding. It is shown, that this power may exceed the value of 20 kW/kg. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kiselev M. A., Ismagilov F. R., Sayakhov I. F. Electric actuators for aircraft aerofoils control. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 141-148. While increasing the aircraft degree of electrification hydraulic drives fed by centralized fluid power systems substitution by off-line electric drives is assumed. Translational motion power actuators with ball-and-screw gear are widely used nowadays in aircraft flaps, slats and adjustable stabilizers control systems, and operate reliably for a few minutes per flight. In the absence of strict requirements to the dynamic characteristics of electric actuators, such as high-lift drives, simple electromechanical actuators with controllable electric motors and mechanical gear are already in use. During the flight of an aircraft, controlled airfoils are exposed to varying loads under the influence of airflows. These loads cause significant mechanical stresses in the electromechanical actuator, leading to accelerated wear of mechanical actuator components. Another problem with the existing electric actuators is their excessive weight and size as well as difficulty to ensure compliance with the stringent operational safety requirements. Thus, the goal of this research consists in eliminating these deficiencies and improving the energy and operating characteristics of electric actuators. It is necessary herewith to consider the operation of an electric drive either in active mode, when the energy is spent to set the running gear in motion, or in passive mode, when the running gear is fixed in a certain position and exposed to significant mechanical loads caused by aerodynamic forces. Based on the presented aerodynamic forces calculations, we analyze the designs that solve the stated problems. These designs allow implementing both the passive and the active electric actuator modes. We propose a design that makes electric actuators more reliable and durable while operating in the passive mode. This is achieved by removing the output arm from the deadlock position to allow a limited range of deflection and by damping vibrations and oscillations caused by aerodynamic forces within that range. However, oscillations damping by electromechanical dampers is not always efficient, since it may result in weight and size figures increase under high mechanical loads. This problem could be solved by implementing the electric actuator structure with flexible coupling between the ball-and-screw gear and remaining actuator components in the form of modified elastic compensating clutch. This proposed flexible coupling demonstrates small weight and size figures compared to with electromechanical dampers under heavy loads. Thus, such structure can be realized also in spacecraft. Judging from the above said, the considered electric actuator construction arrangement allows reduce its weight and size figures. The resource increase in electric actuator passive operation mode is achieved by eliminating rigid fixation of the output arm in dead spots and limited oscillations of the output arm in the operating range of a position sensor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lisov A. A., Chernova T. A., Gorbunov M. S. Simulation approach to the study and modelling of electrical converters degradation processes. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 149-156. Under real operation conditions of electrical industry products, the degradation variance of their features should be allowed for. The subject of research is various kinds of electrical converters which even slight degradation results in serious technogenic disasters. The paper considers and suggests basic principles for such type of problems solution, and establishes a number of degradation variances regularities. Characteristic parameters variances analysis allows separate out four most characteristic types of functions for the named regularities description: entire irrational functions or polynomials, fractional rational functions, and functions for processes with description. Evaluation of degradation variances simulation results supposes tabulation of the measured values and selection of such an approximating function which would ensure it the least mean square deviation fr om the tabular dependence. The OLS method ensures the best results for solving the problems of such type. Analysis the considered functions, describing the degradation process, allows state the following: all functions have the initial value, known for the unit in use fr om the its datasheet. Thus, in the course of degradation variance studies it is expedient to examine only the function degradation variations, instead of the whole function. Initial value of the deviations function equals to zero, and its plot passes through the origin of coordinates. While determining the number of parameters of approximation functions, their number would be one less for deviations function. Thus, the order of normal OLS system reduces. The residual resource prediction was performed based on solving non-linear equation, wh ere degradation deviation function takes the normative allowable values. While solving the equation, the function arguments lim it value should be defined as an instant of failure. The evaluation of the residual resource was performed based on the instant of failure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuznetsov P. A., Stepanov O. A. Reactive power compensation automated systems application to prevent blackouts. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 157-163. The main task of the article consists in electric power grids basic emergency modes, leading to rolling blackouts, analysis, and high-speed reactive power smooth regulator (RPR) design for the existing domestic reactive power compensation systems (RPCS). Failures analysis at industrial enterprises and substations revealed that one of the main reasons resulting in avalanche failures and blackouts is reactive power circulation, representing an integral part of complex electromechanical mechanisms functioning. However, the excessive amount of reactive power and circulation leads to complications and serves as the cause of failures. Various reactive power-compensating systems, such as either static (capacitor installations), or dynamic (synchronous compensators), are widely used in the industry. However, preference is given to the static ones due to low price and durability. Their implementation for the most part pursues only economic benefits, namely energy cost reduction. Nevertheless, with certain updating these installations can be implemented successfully for failures, resulting in blackouts, prevention. On the example of compensating installation, developed by the authors, they suggest to replace one of the critical elements for the purpose of regulating properties improvement. This element is Reactive Power Regulator of foreign manufacture. It has a number of disadvantages, which presence may result in cascade fault. The proposed new regulator is a thyristor reactive power regulator consisting of a transformer, network mode sensor, regulator, control block, thyristor switches and a filter. This paper presents the schematic diagram and computation algorithms for voltage level sensor parameters, network mode sensor parameters and filter parameters. The computation of the unit reliability is presented either. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vavilov V. E., Bekuzin V. I., Aiguzina V. V. High-speed slotless generator, integrated into auxiliary power unit: design and experimental research of the scalable prototype. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 164-175. The paper presents the design and experimental research of the high-speed slotless generator scalable prototype with strip-wound stator core, integrated into auxiliary power unit. The experimental research and computer simulation of the scaled-size prototype in no-load and on-load modes were conducted. They revealed that this generator demonstrates minimum rotor losses and voltage ripples, as well as high specific energy characteristics. The high-speed slotless generator scalable prototype computer model was developed with Ansoft Maxwell software. Experimental data deviation from computer simulation results does not exceed 5%. From the results of scalable prototype computer simulation a full scale computer model of high-speed slotless generator was developed. The main parameters of the high-speed slotless generator were defined and compared with the parameters of the slot-type high-speed generator. The comparison revealed that the slotless variant demonstrated lower losses (by 600 W) with minimal weight and size parameters (not more than 0.2 kg/kW), high efficiency, minimal negative high harmonics effect, absence of the slot ripples, and the simple production technology. Thus, the obtained data shows that the high-speed slotless generator with he strip-wound stator core made of amorphous alloy can be implemented as the generator integrated into the auxiliary gearless power unit. It proves also the possibility of its application in aircraft industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Le D. T., Averin S. V. Simplified spice vector pulse width modulation algorithm for asynchronous motor speed control. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 176-184. The paper presents algorithms for voltage generation at induction motor (IM) windings in vector pulse width modulation (PWM) mode while IM rotation frequency regulating. These algorithms ensure smaller amount of computation, allowing eliminate through currents in the inverter power stage. Vector PWM (VPWM) employs 8 states of inverter switches for IM control. The paper considers the possibility of extra intermediate vector states of the switches, which would not cause through currents occurrence in the inverter and allow include them into IM speed control algorithm. For through current elimination in transition periods between zero vectors and basic and non-zero basic vectors the authors suggest implementation of intermediate switches conditions of the switches, which will be operated on as vectors. Let us consider treat these vector as variables. The authors analyzed the usage of a group of vectors V01, V02, V03, V04, V05, V06 or V10, V20, V30, V40, V50, V60. It allows obtain two most promising algorithm. To control IM output voltage and frequency parameters employing PWM mode, the assemblage of the transitions between acceptable ones, when at least one syllable of a control word would be inverted, will be referred to as vector subset of permitted dangerous bilateral transitions. The simultaneous switching of both switches of a totem pole corresponds to the dangerous transition. In the suggested algorithms, the transitions are in parallel with Karnaugh map sides, which means that they do not cause through currents. Vector PWM voltage and frequency parameters will be considered only in the time interval corresponding to the half of the sector. Simulation was carried out varying time interval of vector V0 existence for regulating generated voltage value under invariable TV4/TV6 ratio (for s the first sector). The effect of n parameter on the quality of IM drive in VPWM mode. The simulation was performed with MATLAB Simulink. Simulation results are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kalugina M. S., Remshev E. Y., Danilin G. A., Vorob'eva G. A., Pekhov V. A. Combined thermoacoustic method for titanium alloy structure modifying. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 185-196. The paper studies the possibilities of using acoustic emission and gas-dynamic processing (thermo-acoustic processing) methods for initial check of a material (titanium alloy) instead of a traditional method, i.e. optimal heat treatment mode selection. Implementation of thermos-acoustic processing as an extra treatment of TC6, BT16 and BT23 alloys, demonstrating low mechanical properties in the initial state, ensures grains refining and improvement of property package up to the required level. Physical features of titanium alloys and specifics of obtaining semi-products on their basis require that a manufacturer should know and allow for these semi-products initial state (mechanical properties, microstructure, etc.) while process design. Thus, the manufacturer should possess the technique allowing promptly estimate and correct mechanical-and-physical properties of the basic material, and in certain cases of a complete spring either. For the experiment, the authors sel ected the alloys fr om various foundries (mechanical properties, microstructure, etc.). The presented study area of application is titanium alloys implementation for springs, employed in airspace and other special equipment manufacturing, where the quality of basic material predetermines largely the quality of a final product. The carried out studies in the area of the basic material quality in spring production allows draw inference on the possibility of a certain initial check modernization, as unattainable part of a component manufacturing process. It is established, that acoustic emission method allows qualitatively estimate the microstructure without labor consuming estimation methods and take a decision on treatment schedule of manufacturing process. ATAP implementation as an extra processing of TC6 alloy, demonstrating low mechanical properties in its basic state, ensures grains refining and improvement of property package up to the required level. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kyaw A. L., Artemev A. V., Rabinsky L. N., Afanas'ev A. V., Semenov N. A., Solyaev Y. O. Monolayer properties identification in carbon composite with nano-modified matrix. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 197-208. The results of monolayer elastic and thermos-elastic characteristics identification in carbon composite samples, produced by employing of epoxy matrix containing 0.2 wt.% of fullerene soot are presented. The composite samples with reinforcing schemes [02/904/02], [+452/-454/+452], [04], [904] were fabricated by vacuum shaping. The fullerene soot was preliminary added to a binder and disperse using mechanical and ultrasonic mixing. The composite monolayer properties were obtained based on the analysis of the results of mechanical tests of the samples with various reinforcing schemes and inverse problem solution. The multilayer properties valuations were obtained, using micro-mechanical, analytical and numerical modeling and solving corresponding averaging problems. Mori-Tanaka averaging method was used for analytical computations for cylindrical embedding problem. Numerical calculations were performed using finite elements method at representative fragments, containing unidirectional fibers. The computations used initial matrix properties values obtained from the experiments, and matrix containing the fullerene soot. The paper demonstrates that the results of numerical and analytical computations performed to evaluate the unidirectional layer properties are sufficiently close to each other. It follows from these computations that in case of impurities agglomeration, addition of nano-filler should lead in the first place to transverse elastic modulus increase and monolayer shear modulus due to matrix tightening. Pitch module should vary insignificantly since it is defined by filler properties. With the filler addition, the monolayer Poisson ratio practically should not change. These results do not correspond with the experiment, except shear modulus increase. Unlike the predicted monolayer transverse elastic modulus increase, the experiments revealed its decrease. It follows from the experiments that monolayer Poisson ration significantly decreases, which was not predicted by computations. The obtained results demonstrated the matrix embrittlement while implementing the selected nano-modification technique and the necessity of either filler volume fraction decreasing, or changing the technique of its dispersing in the binder. The authors plan to use identified values of composites' monolayers elastic and thermos-elastic characteristics hereafter to describe the residue stressed-deformed state of carbon composite construction elements to reveal the possibilities of reducing residual stresses and shrinkages in the structures with asymmetric reinforcing schemes, using matrixes containing carbon nanoparticles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bychkov A. N., Fetisov G. P., Kydralieva K. A., Sokolov E. A., Dzhardimalieva G. I. Nanocomposite materials based on metallic nanoparticles and thermoplastic polymer matrices: production and properties. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 209-222. A line of composite materials based on low-density linear polyethylene (LDPE) thermoplastic matrices, polypropylene (PP) and metallic nanoparticles was produced by mixing in polymer melt. The results of dynamic mechanical analysis of PP based composites with metallic nanoparticles, namely the product of Co (II) acrylamide nitrate complex and 2% FeCoAAm co-crystallizatant thermolysis, within the temperature range from −50 °C to +150 °C revealed, that low concentration of nano-filler (1 wt.%) does not lead to noticeable changes in dynamic elastic modulus, nano-composite mechanical losses and loss tangent. Thermooxidative degradation results indicated the increase of thermostability for above said PP-based composites compared to the initial PP at 4 and 8 wt.% of nanoparticles. The authors obtained nanocomposite materials based on polyolefin matrix and pre-synthesized by chemical co-deposition magnetite nanoparticles such as LDPE-Fe3O4 and PP-Fe3O4. According to X-ray diffraction analysis, the major component in the system was magnetite nanoparticles with an average size of 15 nm. These results correspond to scanning electron microscopy data. The paper demonstrates that with the increase of nanoparticles content in polymer, and with magnetite high content in particular, the elastic modulus increases, and the tensile strength value decreases. Thermal behavior analysis in the PP-Fe3O4 (at 4 wt.%) system indicates that nanocomposite thermo-oxidative degradation reduced compared to the initial polypropylene, and the temperature of maximum degradation start-up increases from 300°C to 385°C. Composite materials based on LDPE and Al65Cu22Fe13 with alloy (0.1 to 10 wt.%) were produced. The paper demonstrates that the presence of quasi-crystalline alloy as a filler leads to composites strength properties improvement. Unlike LDPE-Fe3O4 systems, a tensile strength of LDPE-Al65Cu22Fe13 increases with low filler concentrations. Protective action of the nanocomposite systems under test in relation to beta-radiation was studied using dose metering method. It was demonstrated that with filler content increase in LDPE-Al65Cu22Fe13 and LDPE-Fe3O4 composites beta-radiation flux attenuation occurs. A high correlation between the portion of passing beta-radiation and relative dielectric constant of composite materials based on thermoplastic polymer matrix with metal-filler was observed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Prosvirina N. V. Development and implementation of efficient production management principles based on lean production concept at the aircraft engine-building enterprises. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 223-232. The paper tackles the topical issues of staffing training and forms of factory organization at the aircraft building enterprises based on lean production concept. While production development in Russia and its share increase in the global market, the issue of product company optimal management comes up. The lean production program leads to creation of learning organization with stable, continuously progressing processes, aimed at searching for non-productive losses and their minimization. The lean production becomes the topmost factor of efficiency increasing, competitive stability of an enterprise and reliable technique for all kinds of all kinds of expenditures. In an aggravated competitive struggle at domestic and world markets, the key factor of Russian engine-building companies' success is associated with their flexible response to rapidly changing market demands. This requires development and implementation of a number of measures aimed at improving the efficiency of production and enabling enterprises to enter the global market as providers of competitive aircraft engines. The main problem at domestic engine-building enterprises consists in production systems modernization. Many companies take the mass production concept as a basis of their production system, which does not meet modern industrial requirements to goods and services production, and does not take the expected effect. Thus, it is necessary to carry out the production system modernization, taking more efficient and productive system as its basis, engaging all management and stuff of the company in this process. Effective organization of production at aircraft engine-building enterprises is a significant and special component of the competitiveness analysis due to its magnitude to production encompassing and time scale parameters of their implementation. Thus, the organization of competitive aircraft equipment manufacture should allow for all kinds of losses and expenditures, and implement efficient production system, including the great majority of methods, techniques and tools. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churilina I. V. Cost management at the space-rocket industry enterprises. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 233-240. The paper tackles the issue of the cost management methodological approaches enhancement. The main purpose of the paper consists in developing the cost management financial mechanism based on EVA concept for the space-rocket industry enterprises as an instrument of increasing the enterprise financial stability and competitiveness. System approach to financial management theoretical basics summarizing and analysis composes a methodological base of the research. While conducting the research the author employs the methods of financial analysis and forecasting, economic-mathematical modeling and expert assessment. The author identified space-rocket industry enterprises' specifics and explored cost management methods existent in economic science. The economic value added concept is a method on which basis the financial mechanism of cost management is developed. As a result, the indicators of the EVA concept were modified. The adaptation of the basic indicators of the EVA method to the cost structure of the space-rocket industry enterprises and the technique of calculating EVA are specific to the organization of production and the budget process. They allow identify the basic elements of economic value added cost, i. e. purchase of materials (EVAм), staff salaries (EVAт), equipment handling (EVAа) and other expenses (EVAп), characterizing the efficiency of rocket space technique production process. Moreover, the optimal cost financing structure was identified. The results of the research were proved on the example of the space-rocket industry enterprises. Finally, we conclude that the most expensive source of funds are borrowed funds, which effective use will consist in material and other costs financing at their expense, but costs of labor and depreciation deductions is preferable to be financed from the own funds. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gyazova M. M. Cargo ramp aircraft implementation forecasting based on simulation modeling. Aerospace MAI Journal, 2017, vol. 24, no 2, pp. 241-248. The paper is devoted to the issues of cargo air transportation market development in Russia, and exploration of ramp cargo airplane An124-100 operation in the market. At present, this plane carries out the major part of transportation of heavy oversize cargo. The plane demonstrates a unique combination of capabilities, as it is one and only air transport for oversize cargo alternative overseas transportation. The plain allows also increase safety and reduce damage probability of cargo, compared to overseas transportation. It is capable of delivering cargo to far-out regions, where there are no auto-road and railways, horizontal loading and unloading capacity through nose and tail ramps, as well as lowering the aircraft floor and unloading without specialized external cargo-handling equipment. To forecast economic indices of the plane of a specified type simulation model run by Vensim program. The conclusion is drawn that with growth of heavy oversize cargo air transportation demand, the necessity for organizing in Russia the serial production of aircraft equal to An-124-100 increases. Analysis of cargo transportation world market modern tendencies revealed apparent significant potential of the sector of economy in question and its direct interrelation with such factors as the degree of technological development of the country, the State participation in the trading processes and general level of economic development. The branch of group air transportations should be considered as one of aircraft industry strategic orientations totally and enjoy the State support. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bokhoeva L. A., Kurokhtin V. Y., Perevalov A. V., Rogov V. E., Pokrovskii A. M., Chermoshentseva A. S. Helicopter structural elements and components fatigue resistance tests. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 7-16. The paper considered fatigue resistance testing of helicopter structural elements on the example of helicopter rotor blades samples testing. Endurance testing of aircraft equipment components and structural elements consists in laboratory reproduction of external disturbances corresponding to the standard operating conditions, cyclic loading and functioning. However, these tests do not include studies related to the gradual damages accumulation leading to cracks initiation and propagation and finally to structural damage. In this regard, studying the process of cracks growth while full-scale tests of the samples presents special interest. The paper presents the brief description of blades full-scale tests process with concurrent video shooting. The samples are subjected to static loading, with subsequent additional bending load moment of variable sign. Video records of cracks growth were processed, and data on the crack subcritical growth time was obtained. This information is presented by the diagram, illustrating the crack growth time dependence of the crack growth rate. The paper analyzes measuring and test equipment used while testing for recording values of tensions occurring in the studied samples, due to bending load of variable sign applied to them. Fatigue resistance characteristics were determined, and fatigue graph was plotted. Arithmetic mean and root-mean-square deviation of endurance limit stress are obtained also. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Marakhtanov M. K., Veldanov V. A., Dukhopel'nikov D. V., Karneichik A. S., Krutov I. S., Makarov A. A. Modeling a spacecraft fracture mechanism occurring as a result of its metal components inertial explosion at collision. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 17-25. The accidents of two Earth satellites collision when impact velocity of the spacecraft abeam reached 10.5 km/s. This velocity is several times than that required for a crystal lattice inertial explosion of the metal, constituting the spacecraft body. Inertial explosion parameters of metal components, which can occur at the contact point of the collided spacecraft, are studied. The paper demonstrates experimental and computed data on the collision velocity, causing such an explosion, as well as motion speed and explosion vaporous products temperature, reaching 22 000 K. It shows that the time necessary for metal transition from the solid state to luminous atomic-vaporous mixture reaction excitation does not exceed 2 µs, if this transition was caused by mechanical shock. Mass ratio of the exploded metal was determined. All experiments were conducted using lead samples. Metal preserves its solid state until the metallic binding energy is enough to preserve its crystal lattice. This energy equals to the sum of a metal heat content from the temperature T = 0 K plus evaporation heat up to the sample sublimation. Acquiring the energy of the metal ceases to be a condensed media and passes to high temperature vapor condition. Such transition occurs while siderite or nickel meteorite collision with Earth, or spacecraft. The experiment procedure was as follows. The lead ram tester of a cylindrical form weighted 0.027 kg, had the diameter of 14.5 mm and length of 15.2 mm. Its velocity was v = 1128 + 14 m/s. The lead target was of a parallelepiped shape of 67 × 82 × 15.5 mm and weighted 0.91 kg. The target mass remained after the lead ram tester stroke was 0.68 kg. The rest lead target mass (as well as the ram tester) evaporated. During the experiment, the velocity of moving elements was determined by images movement on video frames, recorded by Phantom V 16 model 10 video camera. The exposure time per one frame was 1 / 156000 s-1, and the shooting speed was 25 000 frames per second. The shock waves pattern in inertial explosion vaporous products of the two lead structures was obtained. The Mach number measured in the open air equals 2.36. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezrokhi Y. A., Kalenskii S. M., Kizeev I. S. Double-flow turboprop with afterburner weight indices estimation at the initial stage of its design. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 26-37. The paper considers perspective approaches to double-flow turboprop with afterburner weight estimation technique forming at the initial stage of its design, having potential of implementation with acceptable accuracy for new generation of engines. The authors carried out analysis of the existing weight estimation techniques with different degree of their elementwise particularization, and under various methods of main regularities selection, linking engine gas-dynamic and weight parameters. “Modular” and integral engine weight estimation techniques were considered, and weights of 16 engines were computed using these techniques. Based on carried out analysis, the sel ected variant of integral approach was updated with allowance for gathered statistical data on new generation of turboprop mass and gas-dynamic parameters. A correction factor, characterizing the generation to which a certain engine is related according to its weight efficiency, was determined. Recommendations on weight estimation of an engine design based on the existing gas generator were developed. These recommendations imply implementation of correlation dependencies of the engine's separate modules weights fr om its operation parameters within the framework of the developed technique. To determine the weight of turboprop with afterburner, developed on the basis of scaled or modified gas generator, a combined technique matching up either integral or “modular” approaches was formed. Finally, the recommendations on implementation of the formed techniques with allowance for their future development by invoking additional data, including the data on newly developed engines, are provided. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moshkov P. A., Samokhin V. F. Noise and acoustic signature reduction methods for unmanned aerial vehicles with engine-propeller power plant. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 38-48. In recent years, the problem of acoustic signature has become particularly actual and a topical due to the extensive use of combat aircraft systems with unmanned structures, solving decisive reconnaissance and strike tasks, for which low figures of acoustic signature ensuring is of prime importance. The paper considers basic techniques for engine-propeller power plant noise reduction of aircraft type UAVs, including single air propellers of various structures and configuration, as well as piston engines. Based on semi-empirical model the authors proposed equations allowing evaluate the effect of the diameter and number of blades on tonal components of the propeller noise in the condition of constant thrust, aerodynamic and geometric similarity of blade profiles, as well as the Mach number of the tip speed. Acoustic testing of Yak-18T light aircraft with two- and three-blade propellers, F30 and MAI-223M, performed at the Moscow Aviation Institute airfield, generally confirmed these equations qualitatively. The propeller diameter decrease of a small-sized UAV with piston engine was considered as one of the options for noise and signature reduction. It was found, that the diameter decrease by 3.3% resulted in approximately 300 meters reduction of the distance to the ground checkpoint, which a small-sized UAV can approach without the possibility of being detected. The features of acoustic pusher propellers and proposed methods for noise reduction are described. Based on the flight test the aircraft noise reduction afield technique by axial clearance increasing between the pusher propeller and the wing located in front of it was proposed. The paper demonstrates that with the considered clearance increase by an amount greater than the wing chord, the negative effect of the propeller mounting in pushing arrangement is practically eliminated. UAVs designers can implement the engine-propeller power plant noise reduction methods, presented in the paper. Finally, the authors outlined the ways of further studies aimed at solving the problem of developing low-noise power plants for small-sized unmanned aerial vehicles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorob'ev A. G., Vorob'eva S. S. Liquid low-thrust rocket engine boundary layer numerical study. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 49-56. The subject of the work consists in numerical study of the boundary layer on the wall of the combustion chamber and nozzle of a liquid rocket thruster. Using numerical integration method of the system of differential equations describing the boundary layer, the boundary layer parameters were computed as a function of the engine operating conditions and the pressure in the combustion chamber. To close the system of boundary layer equations, the values of turbulent moment and heat transfer coefficients are calculated by determining mixing length by the equation suggested by Prandtl with Van Driyst correction. A numerical method for the boundary layer computation was realized as a software with the working interface in Excel. The program operates with relative dimensionless parameters. Low-thrust LRE, burning such fuel components as nitrogen tetroxide and asymmetrical dimethyl hydrazine with the thrust of 200 N, parameters served as initial data for computation. The working flow parameters were taken according to the results of thermal and gas dynamics computation with average mixture ratio “on the wall” over the length of combustion chamber. The paper presents computation results of the boundary layer parameters for the MAI-200-1 object engine: the displacement thickness, relative velocity profile, friction coefficient, nozzle flow rate. The change of boundary layer thickness and flow rate coefficient for the object engine, and engines with working pressure of 2 and 3 MPa were calculated. The paper made clear that an increase in the combustion chamber pressure increases the relative thickness of the boundary layer, while nozzle flow rate falls. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolodyazhnyi D. Y., Nagornyi V. S. Electric field effect on kerosene-air mixture combustion products temperature distribution. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 57-62. The paper presents the results the experimental study of appropriately organized electric field effect, using electric unit for aviation kerosene impact (EUAKI), applied to kerosene flow at the nozzle inlet, on the kerosene-air mixture burnout temperature. TC-1 kerosene was used as hydrocarbon fuel. The air was fed to combustion chamber at the temperature of 150°C. Fire tests were carried out on the Samara State Aerospace University workbench. Experiments on gas temperature at the outlet of combustion chamber gas collector characterization were performed by direct gas temperature measurement with single-point chromel-alumel thermocouple (operating temperature range from 0 to 1,100°C) shifted in the plane of the flow cross-section at the distance of 20 mm from the gas collector cutoff of combustion chamber combustor can. The electric field parameters, such as voltage type at the EUAKI electrodes, its amplitude and frequency, and EUAKI design parameters effect on gas temperature distribution at the combustion chamber outlet while kerosene-air mixture burning. Atomizer modules herein, consisting of SPA “Salut” fuel atomizer itself and various EUAKI design with electric fields organization from different electric power supplies were varied. It was demonstrated that implementation of EUAKI directly connected to the fuel atomizer inlet as a part of atomizer module by rubber hoses with corresponding permittivity increases the average and maximum gas temperature at the gas collector outlet up to 4.09% and 4.88% correspondingly, reduces gas temperature field non-uniformity at the combustion chamber outlet by 10.34% relative to the base. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Finogenov S. L., Kolomentsev A. I. On solar thermal rocket engine structure and parameters selection. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 63-74. The paper considers the solar thermal rocket engine (STRE) with isothermal (one-stage) and two-stage system concentrator-absorber system (CAS). It demonstrates their characteristics in the flight version, revealing rational parameters of the CASs under consideration, and inexpediency of attaining maximum possible hydrogen heating temperatures and maximal specific impulse with higher mirror booster accuracy in both structures. For considered STRE schemes, implementation of heated hydrogen afterburning reveals the possibility of solar concentrator size reduction together with upper stage fuel compartment size reduction. Selection of expedient parameters of CASs under consideration may shift towards less accurate mirrors with less absorber heating temperatures followed by minor deterioration of upper stage ballistic characteristics. To enhance STRE energy characteristics the authors suggest CAS with two-stage solar emission absorber, which heating level corresponds to the irradiance level in focal light spot. The highest hydrogen heating temperature occurs in the central part of the absorber. The specific impulse herein significantly exceeds the like when employing isothermal absorber. Two-stage absorber efficiency computation regression model, based on energy balance of heating stages, allowing obtain rational temperatures relationship corresponding to maximum absorber efficiency, as well as optimal temperatures distribution along heating stages was developed. The obtained regression dependencies can be used for computation of real STRE, operating as a apart of space upper stage, flight characteristics. The paper demonstrates STRE flight characteristics with considered CASs, defines their specific flight It was demonstrated that in case of two-stage CAS mass efficiency exceeds the like for modern liquid means of interorbital transportation more than 2.3 times. On oxidizer excess coefficient selection in case of hydrogen afterburning it is necessary take into account that for STRE with two-stage absorber each percent of concentrator diameter decrease corresponds to about one percent of payload weight reduction. This factor should be considered while practical design of various STRE structures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Siluyanova M. V., Chelebyan O. G. Shadow particles anemometry method implementation for aerosol characteristics behind the flame tube heads of low-emission gas turbine engines. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 75-82. The process of the liquid fuel atomization and vaporization is of fundamental importance for the GTE combustion chambers effective operation. Normally liquid fuels are insufficiently volatile, and therefore must be dispersed in large numbers of small droplets with an increased evaporation surface area required for the ignition process and combustion of the fuel-air mixture. The paper presents the results of a new unique shadow particles anemometry method for studying parameters of the flame spraying nozzle unit of low emission combustion chamber (LECC) of the pneumatic type. A detailed description of the PSV measurement method and calculation algorithm when processing the data is presented. The special feature of this method consists in its relation to a method of direct measurement of various aerosols characteristics and provides highly accurate measurements of parameters compared to other methods. PSV method uniqueness consists in the fact that in addition to the spray basic parameters, it allows also define the shape of the particles, by freezing the shadows of droplets images in the measuring volume of camera matrix and high-speed pulsed backlighting. Tests were conducted on a CIAM laser diagnostics workbench in the open space behind the nozzle unit with fuel (kerosene TC-1) pneumo-spraying. During the tests distribution of fuel particles over size and shape at the distance of 30 mm from the nozzle section in the cross-section of spray pattern was obtained. Implementation of a new Shadow particles anemometry method (PSV) allowed verify experimental data, obtained earlier by the phase-Doppler anemometry, and the method itself has demonstrated its efficiency and effectiveness, as measured in terms of dense aerosols. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Desyatnik P. A. Optimization of highly automated aircraft handling characteristics in directonal control channel. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 83-95. Topicality of stability and controllability characteristics selecting methods development, when employing rudder control, is caused by a number of incidents stipulated by the directional control channel drawbacks. An aircraft controllability in directional channel is completely defined by its dynamic characteristics, sensitivity and control efficiency characteristics, as well as by the characteristics defining yaw/roll motion interaction. The paper considers earlier developed aircraft controllability criteria in directional control channel and analyzes them from the viewpoint of applicability to modern passenger plane with advanced automation. One of the issues tackled in the paper consists in ensuring aircraft reasonable dynamic characteristics. All existing regulatory documents usually place demands on dynamic characteristics from the viewpoint of ensuring enough response speed in aircraft control channel. However, earlier studies revealed that unreasonably high response speed could become the reason of aircraft so-called «sharp response» on pilots effort. Thus, the requirements to should have upper bound. The paper presents the technique of criterion parameter determination, allowing determine an aircraft inclination to sharp response occurrence and the ways to its elimination by relevant selection of control system characteristics. For modern aircraft with V-shaped wing and engines mounted on pylons, parameter, defining aircraft directional and lateral motions interaction, may attain rather high values. Automation introduction allows decrease this value, so that its equivalent value, i. e. the value with account for automation operation achieves an optimal value. The paper presents control system parameters selection technique ensuring optimal yaw/roll motion interaction. The authors envisage two criteria to determine optimal control sensitivity. One criterion allows estimate sensitivity optimality in time domain, and the other in frequency domain. Both criteria give the same accuracy of the obtained results. The paper presents detailed technique for optimality evaluation of rudder control sensitivity in relation to aircraft dynamic characteristics and control stick loading characteristics. The developed criteria give physical vindication of directional control channel characteristics optimality. They can be applied not only for preliminary selection of characteristics in directional control channel and ways of their realization on modern highly automated aircraft, but also for evaluation of mounted on the in-service aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gelvig M. Y. Aircraft pilots actual external field of vision charting technique. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 96-102. An adequate external field of vision fr om the pilot's station is one of the topmost conditions of safe and comfortable aircraft control including a helicopter. Explicit numerical values of vertical and horizontal vision angles from the main sighting point “C” are specified by regulatory documents, in particular by Aviation regulations (FAR-29). For clarity, the normative field of vision (FoV) is usually represented in the form of a chart in rectangular axes, wh ere и are vertical and horizontal FoV angles respectively. The opening outlines should comply with normative chart as much as possible. Currently used methods of view assessment, including a measuring method (natural and virtual with 3D model), are rather labor consuming, as they require human processing of measured data. Besides, with the initial data change, such as main sighting point “C” position, all the measurements must be repeated. The author has developed an interactive technique of structural FoV plotting by means of Siemens NX8.5 – the basic 3D CAD system of the company. However, structural FoV does not take account for pilot's head mobility and human vision binocularity. It results in overestimated, sometimes impracticable, requirements for geometry of cockpit openings.
As a continuation of the above said research, the development of plotting technique for so-called actual FoV, complied with Standard 1 00444-81 and with due account of the above mentioned factors, has been carried out.
This problem was also solved by graphical method with Siemens NX8.5 CAD in a similar way as structural FoV chart plotting. As a result, actual FoV chart in rectangular coordinates has been obtained. All plotting, like structural FoV, are fully associative. With input data change, the geometry is reshaped automatically. The author also managed to solve the problem of normative actual field-of-vision boundaries on a crew compartment surface, based on reverse combination of projections and convolutions of normative FoV boundaries in rectangular coordinate system. This allows optimize the location and form of cockpit openings at early design stages. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tatarenko D. S., Korsakov A. A. Aircraft aiming system ballistic support algorithm based on complete ballistic model. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 103-112. The paper deals with accuracy increase of uncontrollable aviation ground target killers implementation. It was found that the existing aiming systems use approximating dependencies in onboard ballistic algorithm, which does not allow provide high accuracy in all combat conditions due to introduction multitudes of assumptions. As is well known, the kernel of a ballistic movement complete mathematical model consists in the system of twelve differential equations, which solution requires the set of means, ensuring its numerical functioning. These include equations describing ambient environment parameters, the system of inertial, traction and aerodynamic characteristics of ballistic objects, as well as data on initial and terminal conditions of thrown bodies' movement. Until recently, the low speed of computing facilities hampered with obtaining solution of uncontrolled air-launched weapons movement differential equations in the course of aiming. However, todays level of onboard digital technology allows overcome this shortcoming. Therefore, in these conditions we have the possibility to realize the onboard ballistic algorithm based on numerical solution of differential equations directly onboard an aircraft in the course of aiming. The authors analyzed the ballistic problems solution accuracy during modern aiming systems terrestrial fire, implementing approximating dependencies in onboard ballistic algorithm, and revealed their main shortcoming, namely, impossibility of ensuring high accuracy of application in all conditions of combat operation, as well as with various operating lives. New technique and ballistic support algorithm for aviation uncontrolled destruction facilities were developed based on complete ballistic movement model solution. It allowed enhance the range of tactical employment due to firing initial conditions definition, atmospheric parameters, and aviation destruction facilities movement trajectories parameters definition; nutation angle prediction; flight trajectory parameters introduction into aiming system, and angular correction computation for aviation artillery-type weapon and uncontrolled aviation missiles, with allowance for the predicted nutation angle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zaichik L. E., Grinev K. N., Yashin Y. P., Sorokin S. A. Control stick force characteristics effect on pilot model parameters. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 113-122. Notwithstanding the great number of publications concerning pilot models, none of them considers the issue of stick force optimal characteristics selection. It can be explained by the fact that pilot describing function in visual signal tracking is insensitive to loading characteristics variation and does not allow reveal any regularities and their effect on pilot model parameters. This paper is aimed at studying the effects of stick force characteristics on pilot model and its components, such as limb-manipulator and neuromuscular systems, as well as finding objective proof of loading characteristics, selected by pilots, optimality. The paper presents recently obtained experimental data on the effect of control stick force characteristics, such as gradient of stick-force damping on pilot model parameters. The effect is analyzed based on pilot model frequency response identified in the problem of compensatory pitch motion tracking. For limb-stick and neuromuscular systems characteristics identification, input strain signal is introduced in addition to visual input signal. Frequency response characteristic computation of various pilot model components was made according to specially developed program, based on fast Fourier transform. Analysis revealed that the force gradient variation affects neuromuscular frequency response, demonstrating thereby a pilot's adaptation to the stick force variations. Due to this, the limb-stick cutoff frequency of the open-loop system remains constant for the force gradients assessed by the pilot as optimal. The force damping does not have any significant effect on limb-stick system frequency response. The obtained results are of regular character and contribute to theoretical and practical aspects of pilot models implementation for aircraft sensitivity evaluation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pashko A. D., Dontsov A. A. Model of active protection element impact on guided missile in calculated space point. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 123-131. The paper describes the process of spatial movement of the aircraft relative to the earth coordinate system by a system of differential equations, taking into account the dynamics and kinematics of translational and rotational motion. The aerodynamic impact of the environment on the aircraft is determined by its configuration, position of the associated coordinate system relative to the velocity of the aircraft center of mass and vector of its angular velocity. To ensure an aircraft steady state flight mode the model solved the problem of balancing, consisting in the engine thrust values, angle of attack and the deviation of the aircraft control organs selection with subsequent solution of the system of differential equations. The output variables of the model are the parameters characterizing the actual position of the aircraft in space. The calculated missile trajectory, represented in the form of differential equations and algebraic dependencies, describes the missile guidance to the aircraft. The result is the relative distance value of the aircraft defined by the elevation angles and azimuth. The rocket direction of motion measurement is made according to the method of proportional guidance. The control system sets the missile maneuver with an overload, directly proportional to the angular velocity of the rocket-target line of sight. Thus, any time it tends to ensure the direction of the missile movement to the set-forward point. Based on the canonical equation of motion of the center of mass of the active protection element the terms of its ejection, to deliver it to the point of space where the guided missile is situated was calculated. By simulating the flow over the active element by turbulent incident flow, using finite volume method in Ansys CFX the authors defined the ballistic coefficient of the active protection element. It allowed us to calculate the resistance function value and produce the data on trajectory and projection parameters of active protection element to the control unit. As a result, this model allows calculating, under different tactical actions of the aircraft crew, the target miss, the orientation angles and missile speed of convergence with the aircraft. When processing simulation results one can obtain the characteristics of the missile encounter with an aircraft, as well as active element ejection parameters for its encounter with the rocket in calculated space point. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ryapukhin A. V. Innovative technological projects in the domain of aircraft and aerospace engineering quality management. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 132-137. The paper deals with project quality management in aerospace industry. It analyses acting domestic and foreign Standards on project management, and offers problems grouping for promotion in the field of innovative technological projects aimed at aerospace products development quality management. The paper suggest to eliminate technological gap between Russia and European and American industrial enterprises, developing samples of advanced technology in the sphere of aviation and astronautics through implementation of practices accumulated in international Standards on separate projects management, as well as programs and portfolios managing. Innovation projects management quality increasing for National design departments should base on quality provision and management integrated system development and putting it into practice based on both ISO Standards and proper Projects and Programs management Standards. The existing classification of design performance and other indices needs to be improved. The author envisages concepts of technology, technological innovation project and technologies transfer. Depending on complexity, technology can be included into economic turn-round. Transfer key criterion means technology working efficiency in terms of technological complexity. The State puts forward the problem of research carrying out on improving the system of innovative projects in the area of technological processes provision and management. Its solution options are significant of applied research planning procedure renewal, and Hi-Tech innovation projects realization technological provision program substantiation at the life cycle early stages, and innovative constructive-technological solutions marketability preliminary estimation, as well as process design planning optimization based on Hi-Tech projects with allowance for economical production. The results of the study can be implemented for new Hi-Tech innovation projects management quality methodology development. The paper practical has practical importance for acting quality management system at the aerospace industry enterprises improvement. It can be implemented also in the process of specialists training in the innovation projects management sphere. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov S. B., Kharchenko I. A., Marchenko M. V., Zhegov N. A. Transformer multifunction switched mode converters for onboard airspace power sources. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 138-145. The paper envisages circuit solutions for transformer multifunction switched mode converters meant for uninterruptible power sources as constituent parts of onboard aerospace electric power facilities and electric power supply systems. All solutions are protected by the Russian Federation priority. The paper is of interest for a wide range of specialists working in the field of aerospace onboard power electronic equipment design. To power actuating brushless motors (aircraft onboard equipment in particular) the voltage higher than that provided by batteries, solar of supercapacitor (ionistor) elements is required due to the necessity of varying magnetic field space forming (either circular or linear) by currents flowing through flexible wires. Ensuring relatively higher voltage level only through series (stacked) low-voltage units, or series connection of the above said batteries with significant supply currents is hampered technologically, and leads to mass and size, reliability and cost parameters reduction. For example, in case of “stacked” units leads burning-out (or break) they should be shunted by diodes with low-voltage conducting junctions. In case of breakdown at the leads of a parallel link, it should be provided with disconnecting fuses. Thus, to increase the voltage level of a primary relatively low-voltage source switched mode converters (SMC or DC/DC converters) based on field-effect transistor switches (MOSFET) with low Rds(on) should be used. They should herewith be reversible to provide feeding batteries intensive charging. As a rule, such converters are included in so-called secondary power sources, or stand-by uninterruptible power sources (UPS) fed by batteries [1].
Aerospace uninterruptible power sources included in onboard electric power facilities and electric power supply systems, acquire primary energy from chemical or solar batteries, either form newly developed super capacitor (ionistor) batteries with relatively low voltage (28 V). As a rule, the UPS output voltages herewith are higher DC voltages (such as 135 V, 270 V, or 540 V), or higher AC three-phase (or single phase) voltage (stabilized or regulated) of constant or regulated frequency (e. g., within the limits of 115/200 V, 360-800 Hz, or 0-115 V, 0-400 Hz). Besides, UPS should provide fast feeding battery charging (accumulator or supercapacitor). In this regard, at least specific requirements are placed on the above mentioned UPSs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kosolapov D. V., Kurbatkina E. I., Shavnev A. A. Mechanical alloying process specifics and factors affecting the processed material properties. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 146-159. This article describes one of the powder metallurgy methods, namely mechanical alloying (MA), used for composite materials production. MA is a solid-phase process of deformation impact on the powder material. MA changes the structure and properties of the processed materials. The authors analyzed the effect of technological modes on the process of mechanical alloying. They described, in particular, the main types of ball mills, employed for МА process carrying out. The authors examined the effect of the impurities on fractional, chemical and phase composition of composite granules, which can both accelerate supersaturated solid solutions and amorphous phases building-up process, and prevent diffusion to form amorphous oxides and phases with work material. The authors demonstrated in the paper that the shape of the shape of the container and grinding bodies could also affect the MA process and its results, as well as MA effectiveness and fractional composition in particular. Shape, size and material of the grinding bodies selection depends on several factors. Generally speaking, the grinding bodies should correspond to two basic requirements, namely, they should possess developed superficial area to provide contact with the processed material, and have enough weight to possess enough energy for processed particles grinding. The grinding media can be not only in the form of a globe, but also cylindrical et. On the Al-50% Ta system example the authors envisaged the effect of globes weight to the weight of a material ratio on the MA process. The authors demonstrated also that the MA rate is one of the most important parameters affecting the process of the processed material grains mixing and grinding, chemical reactions process and phase transformations occurring in solid phase. It is well known, that the greater the mill rotation speed, the greater the kinetic energy transferred to the bodies and particles, and, hence, the intensity of the process increased. However, excessively high rates might cause a number of complications, such as grinding bodies high degree abrading and overheating either of a drum mill, of processed material. The authors also studied the issue of temperature effect on phase and structural transformations during technological process. They noted, that high temperature contributes to phase transitions and chemical interaction, while lower temperature works towards nanocrystalline state and metastable phases forming, as well as allows process plastic materials effectively. Thus, the materials presented in the paper help not only to select the initial charge materials processing mode, but also predict the obtained results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Umarova O. Z., Pozhoga V. A., Buranshina R. R. Structure formation and mechanical properties of heat-resistant alloy based on titanium aluminide under heat treatment. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 160-169. Titanium intermetallic Ti2AlNb (orthorhombic phase) based allows are promising materials for gas-turbine engine elements manufacturing operating at the temperatures of 650 — 700°С instead of heat-resistant steel due to their high specific properties, and also intermetallic super- - and -alloys possessing low technological plasticity. Orthorhombic alloys phase composition and structure strongly affect the final mechanical and technological properties of semi-finished products, which can be controlled by certain of thermo-mechanical and thermal treatment modes. Thus, the purpose of this study consisted in studying the effect of heat treatment on the structure and properties of heat-resistant alloy based on Ti2AlNb titanium intermetallic. In this work, the effect of various heat-treatment modes on the structure, hardness and mechanical properties of the VTI-4 alloy based on Ti2AlNb titanium aluminide was studied. The samples were subjected to heat treatment, X-ray diffraction and metallographic analyses. Besides, the hardness of samples was measured by Rockwell method, and mechanical tensile tests were carried out at room temperature. Based on conducted studies, data on the temperature ranges of phase regions in the alloy was obtained, and a scheme for the two-stage heat treatment was designed. It was stated, that the structure and hardness of the alloy are greatly affected by the cooling rate between the first (high-temperature) and the second (low-temperature) treatment stages. Increasing of the cooling rate from 0.01 K/sec to 10 K/sec resulted in fine-dispersed orthorhombic phase formation; the alloy hardness increased by 5 HRC units, and the strength grew by 100 MPa while maintaining a satisfactory level of 4 — 6% for the plastic properties. The cooling rate after the low-temperature stage had no effect on the alloy structure and hardness. It was shown also, that temperature reduction of isothermal holding in the low-temperature stage by 50°C resulted in the tensile strength increase by 80 MPa, and plasticity decrease by 3%. Designed VTI-4 alloy heat treatment modes on the example of rod semi-finished product allowed form in the alloy structure with different size of structural components. The obtained results allow also predict changes in the strength and plastic properties of other types of VTI-4 alloy semi-finished products according to the need for further forming operations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Klimov V. G. Implementing laser pulse buildup for gte turbine rotor blades reconditioning process design development. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 170-179. The gas turbine engine advancement goes hand in hand with the development of its basic component, namely, gas turbine as the key source of efficiency enhancement of the engine in aggregate. With each turn of gas turbine development, materials and technologies used for its manufacturing became more and more complicated and, as a consequence, expensive. Russia is one of global manufacturers of gas turbine engines. The cost of engines for aviation and power industry applications is considerably high. Thus, on this background its reduction remains the main criterion of manufacturer's competiveness on the market. Besides, we should bear in mind that the gas turbine engines maintenance costs in the course of the engine life might exceed its original cost. Without effective maintenance technologies, manufacturing would incur permanent losses. One of the basic specifics of gas turbine engines consists in their significantly high production costs of a number of their parts and subassemblies with relatively short lifetime, requiring permanent replacement. Rotor blades present precisely these parts. They can be damaged by a great number of factors from changes in the structure to loss of geometry. The latter is the most frequent factor even in the case of insignificant geometry loss. From the maintenance technologies viewpoint turbine blades restoration is the most cost-effective, compared to the other parts of the engine. But the complexity of this task remains the major obstacle to its realization. This article discusses the possibility of using high-temperature solder powders as wear-resistant layers applied by laser pulse buildup, as an alternative to classic wear-resistant composites with tungsten carbide admixture. These materials are undergoing testing for further pen height recovery on the example of the turbine blade of the turboprop starter for NK-12MP aircraft engine, and attaching wear-resistant to its end edge. Based on the conducted studies with Tescan VEGA3 LM electron microscope and Hardness DuraScan-10 micro-hardness meter, together with local abrasive wear tests and various powder materials, such as VPr11-40N, VPr24, VPr27 Rock-Dur 6740, analysis while pulse laser powder buildup, the authors confirmed the applicability of several solder powders as wear-resistant layers for turbine blades contact surfaces recovery. Further, comparative studies of the basic material, soldered and built-up structures of VPr11-40N (having the best figures) solder were conducted to detect hardening wear-resistant phases. The cooling rate dependencies of shaping and VPr11-40N solder strengthening phase size were revealed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zaharova L. F., Novikov S. V., Kudryavtsev M. S. Realization of system approach to the problem of large-scale scientific and technical competitive projects participants integration. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 180-191. Ensuring competitiveness of the Russian Federation in the conditions of strengthening of the global competition defines the innovation development of national economy as the priority direction. This direction realization assumes dynamic and intensive development of the industry basis on development and implementation of radical, cardinal, breakthrough innovations, and primarily technology and product. This, in in its turn, imposes increasing requirements to research and manufacturing base of the Russian industry. Development and upgrading efficiency, productivity of research and manufacturing base of industry represents difficult, complex, coordinated process of its participants' interaction. They involve all the basic, vital and concerned parties, and are aimed at innovative cycle reduction, primarily, at the stages of innovation development and innovation activity growth, and finally, holding leading global positions over key, priority trends of technological development. Realization of this process in the framework of the Russian Federation of a scientific and technology complex development assumes continuous improvement of its organizational and economic mechanism. One of the main methods providing development of a scientific and technology structure of Russia consists in scientific and technical projects realization within the framework of the State order, requiring forming and carrying out competitive selections of such projects. The solution of the above-stated problem proposed in this paper consists in forming specialized organizational and executive structure of a project realization within the system integration of participants-contractors working on the project. This model of forming organizational and executive structure of the project is developed based on the criteria accounting for extra income on the project, possible from implementation of collateral and intermediate product output, while developing research and technology reserve and, thus, under otherwise equal conditions, supplements the project economy and reduces the risks in case of possible losses. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharova I. V. Regional aviation claster evolution factors analysis. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 192-200. The airlines employ flexible approach to strategic planning and conducting regular environmental monitoring of an unstable economy. The purpose of this paper was to adapt the SWOT-analysis to assess regional aviation clusters development. This cluster incorporates enterprises, interconnected by the aircraft lifecycle: aviation enterprises, infrastructure enterprises, operating airlines, scientific and educational organizations. The method of the SWOT-analysis is applied for a specific enterprise and for the aviation cluster as a whole. The author analyzed the factors of the external and internal environment of the Ulyanovsk region aviation cluster. In the studying process the priority of strategic decisions and the most significant capabilities of this socio-economic system, presented the basic economy indicators of this cluster was identified. The study proved that using the SWOT-analysis requires quantification and ranking of external and internal environment factors of the regional aviation cluster. Quantitative correlation of the factors reveals negative phenomena in the external environment of the aviation cluster. The paper offers the expert evaluation of factors according to four criteria such as, factors rating calculations, the relationship of the identified external and internal environment factors of the aviation cluster. The greatest threats for the Ulyanovsk region aviation cluster are as follows: the gross regional product decline, the risk of the growth rates of loans to airlines, severer tax environment for business, dependence of the airlines development from State support. Risks that occur quickly and unexpectedly, devastating to the economic system. If adverse factors are inevitable, but not instantaneous (for example, the outflow of the region qualified personnel, reduction of the population), the production is adapting to them. The research has practical value due to quantitative justification of the priority risks enabling the company to direct the limited resources more precisely. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aminova G. A., Tikhonov G. V. Innovative-investment activities organization and management in small business. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 201-206. The important role in development stability and efficiency enhancement of national economy belongs to small and medium business (SMB), as an echelon of economic dynamics. This is confirmed by the experience of economically developed countries, where the share of small businesses constitutes 56% of GDP. It should be noted that the of SMEs successful development in these countries became possible due to active government support (tax, legal, organizational, personnel, etc.). Unfortunately, in Russia small business is developing slowly, and one of the important reasons consists in the the lack of systematic State support. Today, in the conditions of economic crisis caused by the endless sanctions, special attention should be given to small businesses in the manufacturing industries, especially in machine-building industry. All the more so, in these industries, small business accounts for only 15-16% of all active small businesses. It is important to note, that development in these sectors should be based on close cooperation with large corporations. In this situation, small business can take the risk of the releasing new prototypes of high-tech industrial products. They can also take over the production of components for large enterprises, thereby reducing costs. Organization of small businesses in these sectors requires a fundamentally new approach. At the stage of economy modernization the SMBs need a more sophisticated system of Government support, which should include: development of programs for the development of SMBs cooperative relationships with large manufacturing structures, creating conditions for access to the scientific and technological achievements; assistance in professional staff training and retraining. Thus, for radical strengthening of small and medium business role in manufacturing industry it is necessary to develop a fundamentally new strategy of state support, that will contribute to the development of the organization and management of innovative-investment activities in small business. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volgina K. M., Mineeva K. I., Nemchinov O. A. The ways to improve the transport and logistics activities of aerospace cluster enterprises. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 207-217. Cluster policy has become the dominant trend in the development of many regions. The modern model of aviation industry enterprises consolidation assumes parceling of enterprises on several levels, such as suppliers of raw materials; suppliers of parts and components; suppliers of components and assemblies; sub-integrator; final integrator. Aerospace Cluster of Samara region is one of the high-tech sectors of regional economy. Bearing manufacturing industry seems to be interesting and prospective, since they present the represent components of every rotating mechanism, implemented in every branch of production (including aircraft and helicopter). In addition, products of the plants of the branch under consideration is required either in the region, in the country or other countries. Currently, due to the marked production growth, produced products nomenclature increase and expansion of sales network enhanced the role of logistics significantly. Competent organization of logistics operations allows obtain quite considerable cost savings, which is an important tool for industrial enterprises production and commercial management activities. Sales revenue from products sales factor analysis over three indicators, namely, product unit annual average cost; annual production output, which, in its turn, depends on the staff on the payroll and annual average yield by a single worker. The results of the analysis allowed make a conclusion on the necessity of transportation process optimization, since transportation costs constitute significant share of product cost and final product price. In view of wide geography of sales, the decision was made on the necessity for establishing a distribution warehouse. In the course of calculations, the optimal warehouse location based on cities remoteness from a production point and their annual claims, was determined, and transport selection for production delivery was made. The structure of intracity production distribution on the example of Samara was offered, and the travelling salesman problem was solved, using the two-parameters accrual method, namely time and distance. The study bears the applied nature, and the work has practical value when minimizing transportation costs and embodiment of transport and logistic activities, which will lead to effectiveness enhancement of the industrial enterprise. The study is an applied nature, and the work is of practical value while minimizing the costs of the transport and logistics activities, which will totally increase the efficiency of the entire industrial enterprise as a whole. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galkina E. E., Daynov M. I., Metechko L. B. Occupational safety and health care system economic efficiency at aircraft manufacturing enterprises. Aerospace MAI Journal, 2017, vol. 24, no 1, pp. 218-225. A serious problem of modernity is a problem of flight safety promotion. This problem needs to be addressed not only during operation but also during the design and manufacturing of aircraft. With this objection in mind, it is necessary to ensure implementation of Aviation Activities Safety Management System at the enterprises of aviation industry complying with the State Standard (GOST R 55848-2013), System of Safety management (GOST R 55585-2013), Quality Management System (GOST R ISO 9001:2015), Environmental Management System (GOST R ISO 14001:2007) and Occupational Safety and Health Care Management System (GOST R 54934-2012/OHSAS 18001-2007). Currently, many aviation enterprises are putting into practice the system of Quality Management, but Environmental Management System and Occupational Safety and Health Care Management System are not so actively introduced in industrial enterprise management practice, notwithstanding that Russias annual underproduction due to industrial diseases and injuries goes as far as one trillion rubles. Implementation of Occupational Safety and Health Care Management System will allow reduce these huge losses. With implementation of Occupational Safety and Health Care Management System aviation enterprises acquire real economic effects by improving working conditions, reducing the lost work time as a result of injury and disease, reducing costs of benefits andcompensation for work in harmful working conditions, improve labor productivity and production growth. The equations for economic effect and efficiency of Occupational Safety and Health Care Management System calculation demonstrate that the enterprise acquires not only social, but also real economic effect and social and economic efficiency. The proposed equations are recommended for implementations not only for computing the economic impact and effectiveness derived from the introduction of Occupational Safety and Health Care Management System, but also for management decisions related to the implementation at the enterprises of aviation industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyutyunnikov N. P., Shklyarchuk F. N. Determination of aerodynamic characteristics of an elastic wing with end winglets turning in its plane. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 7-16. Possibility of control by aerodynamic characteristics of a large aspect ratio elastic wing with the end winglets turning in the wing plane is investigated. Controlled twisting of the elastic wing in flight subjected to aerodynamic load which depends on the wing twisting can be carried out by turning of small end winglets in the wing plane with the help of a small power drive. The coupled aeroelasticity problem is solved using mathematical model based on the discrete vortex method for calculation of aerodynamic loads on deformable wing and the wing as a thin-walled weackly-conical beam subjected to bending, transverse shear and torsion. The numerical solution of the aeroelasticity problem is obtained for the large aspect ratio wing with the winglets turning symmetrically forward or backwards in the wing plane. Due to turning of the winglets there appear the end aerodynamic moments which cause elastic twisting of the wing and change the distribution of the aerodynamic load along the wing. For the example of a rectangular wing with the winglets it is shown that the turning of the winglets it is shown that the turning of the winglets in the wing plane creates the end torques and significant angles of twisting of the large aspect ratio wing and as a consequence significant change of the aerodynamic loads and the wing aerodynamic characteristics. The results of calculation show that in a case of a wing which is sufficiently pliant in twisting in the wing plane at the angle δ can be effective for control of the wing aerodynamic characteristics . In case of a wing which is sufficiently rigid in twisting the winglets become ineffective. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Romanova T. N., Paschenko O. B., Gavrilova N. Y., Shchetinin G. A. Maneuverable aircraft horizontal empennage configurations multidisciplinary optimization. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 17-25. The presented work is dedicated to horizontal empennage multidisciplinary optimization method development. Horizontal empennage is a complex technical system, described by the equations belonged to various scientific disciplines. That is why the developed method is called multidisciplinary. The horizontal empennage efficiency can be evaluated by the values of generated pitch moment and its gradient, guaranteeing the aircraft balancing and specified flight maneuver execution. The object region analysis was carried out and various parameters combinations for optimization within the framework of the given problem were determined. We determine optimization line and specify weighting factor for each parameter. Each of the parameters can be set either as a range-parameter, fixed-value, or a set of discrete values. Besides, the simultaneous several parameter setting by a set of tuples, containing discrete parameters values, is possible. The goal function is obtained (where the number of addends is determined by the number of optimized parameters). The goal function structure allows operate with all optimized parameters combinations, regardless of the way of their specifying. Various approaches to the horizontal empennage optimization (methods employing the Pareto principle, and the Hurwitz criterion) were studied. The analysis of the obtained results revealed the insufficient efficiency of the implemented methods. To improve the obtained results, a new multidisciplinary optimization method was developed and suggested. This method employs several evaluation functions to obtain optimal solution. The efficiency of this method is demonstrated using various data sets and input data combinations. The effect of various weighting factors values on the obtained result was studied. The result of the suggested method implementation is horizontal empennage geometrics. The suggested method was realized in the form of a Runtime library and integrated into CAD system Siemens NX 7.5 “Modeling” environment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kochetkov Y. M., Borovik I. N., Podymova O. A., Mavrov V. A., Ishaev R. O. Vortex effects in Ranque-Hilsh vortex pipes. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 26-35. The paper presents the results of computational, experimental and analytical studies of gas-dynamic processes in Ranque-Hilsch vortex tubes. The presented review considers the relevance and need for employing vortex effect for aerospace engineering. It reveals the necessity for vortex tubes with varying geometrical dimensions design for the purpose of operation range enhancement. The authors developed vortex pipe 3D model in SolidWorks system. They realized a viscous gas in vortex tube computation engineering method, and demonstrated its implementation results in gas-dynamics computing FlowSimulation pack. To solve this problem Reynolds averaged Navier-Stokes system (RANS) of equations was used in this work. All computations were performed with orthogonal computing net using finite volume method. Two-parameter model of κ — ε type allowing sufficient flow core resolution was used as turbulence model. Several basic vortex effects, such as injection, heat stratification and vortex inversion, were obtained by computation. All calculation were performed for various structural versions. A series of experiments was conducted with custom-made experimental setup. Processing of the obtained results lead to obtaining hot and cold flows productivity optimums, injection ratio, temperature stratification, as well as adiabatic and temperature efficiency. The experimental results fully confirmed the vortex effects of obtained by engineering computational method. The authors suggest new differential equations for parameters computation in these tubes. The obtained equations establish relation with flow rotation and whirling, as well as explain the enthalpy effect. Computational and experimental as well as analytical studies should continue with regard to optimal structural concept. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moshkov P. A., Samokhin V. F. Propeller-driven light aircraft power plant noise Integral model. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 36-44. The extensive development of small and unmanned aircraft together with existed requirements to permissible levels of noise generated by aircraft, make the noise prediction problem afield topical for prospective aircraft with engine-propeller power plant. The main source of noise afield created by aircraft of such kind is a power plant, consisting of single propellers of various design and configuration, and piston engines. This work integrates and develops the authors’ previously developed methods of computing separate propeller noise and the piston engine noise for solving the problem of forecasting the characteristics of light aircraft and unmanned aerial vehicles power plants’ total acoustic field. The authors suggest a semi empirical model for noise levels, generated by aircraft piston engines in the far field, evaluation with allowance for main noise sources. The acoustic field is considered as a superposition of fields, formed by propeller and piston engine noise radiation. For propeller audio frequency levels estimated evaluation implementation of semi empirical method developed earlier by the authors is recommended. To determine propeller’s vortex noise levels, presumably dominant in the broadband noise of tractor propellers, we propose to use one of analytical models of the trailing edge noise. To calculate the acoustic performance of the piston engine we suggest to use an empirical noise model. The paper demonstrates close agreement between computed and experimental data on power plants with tractor propellers. Experimental data on power plants noise was obtained during light aircraft of An-2, Yak-18T, MAI-223M and F30 acoustic trials under static conditions at the Moscow Aviation Institute airbase. The acoustic field herewith was supposed axisymmetric relative to the propeller axis, while test microphones were located at the ground level. It allowed exclude the interference of sound impact on measured noise levels. The future trends of the study concerning improvement of the above mentioned method and extension the area of its application were formulated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorob'eva S. S., Vorob'ev A. G. Low-thrust rocket engine with internal boundary cooling combustion chamber thermal state analysis. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 45-54. The paper considers the issue of low-thrust liquid engine powered by nitrogen tetroxide and dimethyl hydrazine components non-symmetrical dimethyl hydrazine thermal state theoretical study with account for boundary cooling. The goal of the paper consists in analyzing the results of combustion chamber wall thermal state computation at various operating modes, such as steady-state continuous mode with stationary and non-stationary thermal field, as well as steady-state pulse mode. Liquid rocket engine MAI-200-1 developed in the laboratory of MAI “Liquid rocket thrusters” and undergone fire tes sel ected as a subject of research. For thermal state computation, the authors used mathematical model based on the proposition of combustion chamber wall incoming and outgoing heat flows equality. To solve non-stationary heat problem the differential Fourier-Kirchhoff heat equation in cylindrical coordinates in the case of stationary environment and the absence of internal heat sources is used. Pulse mode of the engine operation is modeled by a quasi-steady approach when non-stationary modes during engine starting and voiding are replaced by the set of stationary modes with intermediate parameters. Oxidizer and fuel were considered as boundary cooling components to protect the combustion chamber walls fr om hot combustion products impact. Computation results prove selection of fuel as boundary cooling component with relative boundary mass-flow rate not less than 20%. Under these engine operating conditions it will allow sustaining the wall temperature within the limits of maximum permissible temperature for ХН60ВТ material. The combustion chamber wall thermal state for pulse operating mode with various on-time and off-time values, such as on-time of 1 s, off-time of 1 s and on-time of 0.05 s, off-time of 0.05 s were analyzed. Presented computation results may be interesting for specialists working in the field of liquid-propellant thrusters, as well as for specialists occupied with spacecraft propulsion systems design. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kamenskii S. S. LPRE control algorithm based on computational-experimental mathematical model using check and proof test results. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 55-60. The purpose of this work consisted in determining the type and functional content of the dependencies, constituting the two-component LPRE control algorithm and obtaining formal description of these dependencies for further use of this algorithm while implementing the engine as a part of a launcher during the flight. It is shown that the task of maintaining the specified for flight conditions engine thrust level values R and mixture components ratio Km are clearly described by specifying functions of regulator assembly drives position in relation to the six parameters: R, Km and four conditions at the engine inlet (temperature and fuel components pressure). This conclusion was drawn by analyzing the structure and functional dependencies of LPRE mathematical model. It was successfully proved by determining such dependencies using adequate fire tests results of a given single-chamber LPRE approximation. To determine control algorithm for LPRE, undergone hot testing, the author suggested implementation of computational-experimental model (CEM), formed according to the results of this engine hot testing. The properties of such model allow carrying out reliable forecast computations of the engine operating procedures parameters in a wide range of the six parameters under consideration, namely operating modes and ambient conditions. The final form of control algorithm represents a polynomial, approximating computation results based on CEM, carried out over six-dimensional array of computed points, defined within the required engine operation range. The adequacy of the proposed approach to the control algorithm formulation in the wide range of all six parameters is validated by comparing the values obtained by approximation with experimental data of a given single-chamber LPRE. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M. Present condition of unsteady turbulent flows study. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 61-67. Heat and hydrodynamic processes are becoming determinant while creating new types of engines for space, aviation and nuclear power systems [1 – 9]. Unsteady hydrodynamic and heat transfer processes study is an extremely important problem of engine building. Only the combination of fundamental and engineering studies provides most effective way to design precise unsteady process model for practical computation. Experimental studies carried out in Moscow Aviation Institute (MAI) hold a prominent place in this field [10 – 17]. The turbulent flow structure studies carried out in MAI reveal non-stationary conditions fundamental effect on turbulent flow structure. Axial and radial velocity and temperature pulsations, average parameters and their correlations were measured as a part of the study. Generalized experimental data reveals significant impact of flow acceleration and deceleration on turbulent structure. Three specific zones in turbulent flow were identified: near wall area y/R = = 0...0.02 (y — distance from the wall, R — radius of the channel); maximal turbulent parameters modification area y/R = 0.02...0.4 and flow core. Significant difference of turbulent viscosity between steady and unsteady approaches up to three times was identified. Comparison of quasi-steady and unsteady approach to heat transfer and hydraulic resistance coefficients revealed the two-times difference. Undoubtedly, such huge difference is unacceptable for space, aviation and nuclear energetics. This result agrees well with experimental data obtained by other authors [18, 19]. Based on non-stationary conditions significant impact on turbulent structure a computation model was developed. With flow acceleration, hydraulic resistance coefficient exceeds relative quasi-steady value by 2 times and more. During flow deceleration, it is 35% less. Experimental study results present reliable base for further theoretical studies to be carried out in MAI [17]. The existing high-Reynolds turbulent models are not able, in principal, to consider non-stationary effect. From turbulence models analyzed in [18], only Menters SST model, which is low-Reynolds model, gives the results close to the experimental. Generalized equations for non-stationary friction and heat transfer coefficients at flow acceleration and deceleration in a tube for engineering design were obtained. The advantage of such models consists in the possibility of their employing for any monotonous flow variation curve, as well as satisfactory convergence with experimental data on hydrodynamic non-stationary gas flow in through channels [20]. Among the works of theoretical character, the studies of Professor Igor Derevich should be noted in the first place. In reference [21] the author considers the gas flow with monotonous consumption decrease/increase, and reveals the causes of computation and experimental data mismatch. For practice, we recommend to analyze the effect of non-stationary processes on a certain jet engine control system. In case, when the processes are principally non-stationary and the required accuracy must be high, a non-stationary model and/or other approaches, considering non-stationaries, should be used. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolodyazhnyi D. Y., Nagornyi V. S., Smirnovskii A. A. On effect of electrical charge on fuel drops surface tension at the atomizer outlet. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 68-78. High-speed transport design, aircraft engines ecology and higher energy efficiency guarantee by improving fuel atomization and air-kerosene mixture quality in aircraft engines intensive research is carried out. To improve fuel atomization and air-kerosene mixture burning we suggest the use properly shaped electric fields in atomizer fuel supplying contours. For the first time the authors studied the effect of variable frequency AC electric field on combustion products chemical composition, when employing kerosene TS-1. Experimental results on the effect of variable frequency AC electric field on air-kerosene mixture combustion products burning rate were presented for the first time. Post-combustion flow speed measuring at the simulative combustion chamber outlet were carried out at Samara State Aero-space University (SSAU). Air-fuel mixture combustion products burning speed experimental determination technique was developed at SSAU. It forms the basis of the research on the effect of AC electric field on air-kerosene combustion mixture products speeds. Employing the speed measuring data, computations of superficial velocity and mass flow ratio were carried out using well-known equations for gas-dynamic functions. The result of experimentation consists in creating Microsoft Access database file with further possible export to Excel. Experimental studies were carried out at SSAU on a single-burner bay of a simulative combustion chamber with operational OJSC “Klimov” duplex nozzle for liquid fuel. We employed a swirler with blades angle φ = 72°10′; gas collector with cone outlet diameter of 133 mm; square spacer plate with square cross-section shaped with square side of 180 mm and a baseline case of offset area holes, when mixer apertures were open. Kerosene TS-1 was used as fuel. Low-pressure compressed air was fed under pressure ≤ 0.75 MPa, and solid tracing particles were used for laser measurements of Ch-4 type. When the AC electric field was applied to kerosene along each diameter, prior to feeding to atomizer, speed values move intermittently up and down. With this, air-kerosene mixture combustion products maximum relative speed reduction was 2.45%, while maximum relative speed of air-kerosene mixture combustion products with applied to kerosene flow AC electric field at the outlet of combustion chamber was 1.425. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov A. V. Study of genetic algorithm implementation efficiency while turboprop engine modeling. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 79-85. Propellers design and development for modern coaxial propfans and their automated control systems are impossible without in-line simulation test benches, which allow reduce testing fee, imitate failure situations, work through control laws and algorithms and determine automated control systems stability margins. Turboprop engine mathematical model plays key role while testing propellers and automatic control systems with in-line simulation test benches. The tests validity depends on accuracy of non-stationary processes reproduction by mathematical model. Due to turboprop dynamic characteristics errors when employing linear methods of modeling, at present, non-linear element-by-element models became widely used. In the course of SV-27 coaxial propfan and RSV-27 hydro- mechanical regulator testing bench, JSC SPE “Aerosila” employs D-27 turboprop non-linear element-by-element model. Implementation of gas turbine engines non-linear models results in significant processing power waste due to the multiple recalculation of the thermodynamic mathematical model while compressors and turbines joint operation point search. To optimize the computational process while using a non-linear turboprop engine mathematical model the authors suggest to use of a genetic algorithm. Genetic algorithm was developed with LabView software, employed with in-line simulation test bench and associated with the engine mathematical model. Genetic algorithm of various configurations and probability values of mutations and number of species in population with in-line simulation test implementation efficiency was studied. The results of the study allowed determine the optimal genetic algorithm configuration and parameters of its optimal operation. In its optimal configuration with a small number of species in population and increased calculating error, this genetic algorithm appeared to be effectiveness comparable to method of successive approximations by bisection. However, the genetic algorithm execution instability, leading to computational resources wasting for some calculated points, makes its implementation in turboprop engine mathematical model, used with in-line simulation test bench for air propellers tests and their automated control systems, impractical. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Siluyanova M. V., Chelebyan O. G. Pneumatic method for uniform air-fuel mixture preparation in GTE combustor. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 86-94. The main objective of the research, aimed at developing combustors for civil aviation, consists in ensuring competitive level of engines emission characteristics. The presented work is dedicated to the development of technology for uniform air-fuel mixture preparation in the flame tube head with respect to aircraft combustion chamber. Gas turbine engine aggregate characteristic guarantee, such as reliable start-up, wide range of stable operation, fuel combustion efficiency and low noxious emission depend in particular on combustor reliable operation. The researches in this field for the most part are agreed herein that achieving high-level of the above said characteristics in the combustor is stipulated, not after all the others, by liquid fuel crushing process quality and its preliminary mixing with air in the flame tube head. It is known that combustion of previously prepared homogeneous air-fuel mixture in model heat generators allows obtain low outlet noxious emission. However, real GTE combustor has no place or the time for such preparation. It stands to reason, that it is necessary the employ the available space and the residence time maximally to direct the air-fuel mixture characteristics drift towards a homogeneous composition. This work presents the results of the designed flame tube head with liquid fuel pneumatic atomizer for low-emission combustor. The paper describes the air-fuel uniform mixture preparation technique in the flame tube head with fine-dispersed spray in swirl flow conditions. Autonomous tests of the developed the flame tube head have been conducted. In the course of these tests the main characteristics of the air-fuel spray formed after burner by a non-contact laser diagnostics method in open space conditions were studied. According to the results of cold tests, the average Zauter diameter of the fuel droplets in the idle mode is about 23 microns. The wide and intense backflow zone is formed near the device axis. To test the developed device and method of air -fuel mixture preparation, fire tests in the model three-burner compartment under high-pressure environment were carried out. The ignition and blowout points under earth conditions have been obtained as the result of tests conducted. The efficiency of lean air-fuel mixture combustion technology has been confirmed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Afanas'ev V. A., Tushavina O. V. Methods and means for thermal-protective materials development verification under climatic effects conditions. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 95-102. Revealing climatic conditions effect in the course of pre-launch procedure of reusable space system is a necessary condition of thermal protection structural components ground development. The climatic tests experiment must simulate positive and negative temperature effects, as well as humidity and precipitation effects. The climatic tests algorithm is designed as a unified processing chain of test set up when a number of simultaneous or consecutive experiments are conducted at the experimental testing bench. The algorithm includes thermal-stability, low-temperature stability, moisture and weather resistance tests. The presented paper describes methods of reusable thermal-protective materials structure testing under the above- mentioned conditions as well as techniques for thermal protection structural elements testing for day-night and seasonal cycling. Recommendations on carrying out the accelerated tests for climatic firmness are given. The approximate scheme of the main climatic factors affecting heat- protective material change in the experiment within the full-year cycle is presented. It is noted, that experimental means for carrying out tests in the conditions of climatic influences must present a constituent part of the experimental means intended for the tests in the conditions of multiple-factor impact on of thermal protection materials. The schematic diagram and photos of the test bench and its components used for heat-shielding reusable materials tests is provided. The suggested methods and experimental facilities for conducting thermal-protective materials climatic tests on multivariable screen tests of tile-type thermal- protective structural elements can be used for consistent assessment of their working efficiency during ground tests. Ground tests of spacecraft units and plants can be conducted by simulating only the major external factors whereas secondary factors impact can be taken into account by introducing corresponding coefficients. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharov I. V., Trubnikov A. A., Reshetnikov D. A. Airborne short-range air-to-air missile guidance system software/hardware complex technical layout and methodological support. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 103-110. Based on the present-day maintenance conditions of modern missiles the paper reveals essential factors, which determine their reliability and readiness support at the required level. This, in its turn, allows establish that up to 70% of failures during instrumental control relate to guidance system, and more than half of them falls at the missile control system. The above mentioned problem manifested itself most acutely with short-range air-to-air airborne missiles. This implies the effective solution of missile control problem by employing guidance system functional control method and its realization based on hardware/software complex. The paper suggests an original solution for short-range air-to-air airborne missile guidance-system loop technical condition, enhancing its functional control methodological efficiency, confirmed by methodological and hardware support synthesis. Functional control scientific and methodological basics are determined by theory of similarity modeling and automatic control theory harmonic balance methods. The functional control effectiveness achieved with this method is determined by basic concepts inherent to the complete mathematical model structure, using the original inciting signal, generated by standard harmonic oscillations installation. These basic concepts include generation of such initial impact, which allow enhance missile guidance system controlled signals observability in system normal operation mode in space of parameters control. The direct guidance system direct control time is one of the important parameters, related to its activation. This time is comparable to missile operation while intended application. It ensures the short-range air-to-air airborne missile specified life substantial saving. Effectiveness of the methodological approach used by authors is supported by developing the guidance system software and hardware functional control complex that prevents introduction of changes to the guidance system hardware and sensors regular system. Thus, the possibility of practical implementation of the methodology, suggested by the authors, into field aerospace forces of the Russian Federation is guaranteed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sokolov N. L. Analytical calculations of a spacecraft motion path in atmosphere. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 111-121. Employing analytical methods for computing spacecraft movement trajectories seems effective while solving a number of problems of practical importance. Analysis of the existing methods reveals that they are based mainly on mathematical models of spacecraft flight along a fore-and-aft plane, as well as some simplified spacecraft motion in space equations. It limits the possibility of their use while solving a number of space exploration problems of practical importance. The paper describes an analytical method for spacecraft atmosphere movement parameters computation. The scientific novelty of the developed method consists in transformation of a number functions in the form of recurrent piecewise-constant dependencies at the finite intervals of spacecraft flight trajectories. After transformation of initial system of differential equations, we obtained the final computation dependencies for velocity and flight altitude, trajectory and course angles, longitudinal and cross range via the atmospheric density. Selection of such an argument, namely atmospheric density results from the fact that spacecraft flight situations can be identified based on calculations of this parameter with further recommendations for control decision-making. Based on the obtained equations we can compute not only the coordinates of spacecraft atmosphere movement, but evaluate the main characteristics, effecting design and technological decision making while a spacecraft design. Particularly, the fast evaluation of maximum overloads values, affecting a spacecraft in aerodynamic deceleration phases is provided. Analytic dependencies can be used while solving a number of variational problems in the conditions of preliminary definition of spacecraft control structure. The tabular matter and graphical data are presented. Computation errors of spacecraft motion trajectory parameters are analyzed. It is shown that these computation errors do not exceed 2-3% with the total qualitative matching of obtained data and of differential equations numerical integration results. Employing of the developed analytical method allows obtain the highly precise computation results of spacecraft motion parameters in the atmosphere. The developed formulas provide high speed of calculations for a wide range of initial data, boundary conditions, and can form the base for spacecraft onboard control algorithms development. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tatarenko D. S., Efanov V. V., Lobanov K. N. Uncontrolled object motion parameters algorithm based on radar data reprocessing. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 122-130. This work relevance is stipulated by the necessity of airborne uncontrolled objet implementation accuracy to fulfill such tasks as forest fire extinguishing, large cargoes airlift delivery, etc. At present, conventional aiming systems do not provide uncontrolled object implementation effectiveness in full measure, since the onboard ballistic algorithm employs approximating equations and demonstrates low accuracy. The authors suggest employ uncontrolled object motion complete ballistic model to improve onboard ballistic algorithm accuracy. The initial conditions can be obtained by determining uncontrolled object motion parameters based on radar signal reprocessing. These parameters determination can be realized with the algorithm, which description and structure are presented in this paper. The paper presents computation results of the signal reflected from an uncontrolled object. These signals reveal that at the distances of up to 200 m secondary modulation harmonics of the first and second order are quite observable in the reflected signal spectrum, under condition of long-continued coherent integration of the signal. The main advantage of this algorithm consists in the procedure of obtaining the unmanaged missile accurate initial conditions, based on the interpretation of the Dopplers effect together with complex application of known mathematical methods of signal processing. The reflected signal from uncontrolled object processing allows obtaining uncontrolled object launching (drop) angle, relative to the center of mass position, velocity and motion trajectory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moiseev K. A., Panov Y. N., Moiseev K. K. Study of overloads occurring while special long loads transportation, carried out by two-link tractors. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 132-136. The paper presents a method for determination of overloads in the cross-section of long restricted articles, which can be employed at the initial stages of launching vehicles (LV) springing systems based on two-link tractor, while moving through rugged topography terrain, peculiar to Arctic zone of Russian Federation. To evaluate overloads in in the cross-section of long restricted article the authors developed mathematical models of “two-link tractor — long restricted article” interdependent system, composed on the assumption of hitch mechanism infinite stiffness, when the LV presents infinite stiffness body, which practically eliminates the possibility of resonant speed modes occurrence while acceleration and moving with maximum speed. The system of differential equations describing dynamic behavior of two-link tractor is divided into three less complicated systems of differential equations, which are solved by the original analytical method, namely combination method. This method is highly effective for dynamic systems study, if a differential equation does not exceed the sixth order. It presents an integral combination of symbolical and parameters variation methods. The symbolical method allows construct the resulting equation for the initial system of differential equations, and find dissipation and eigen frequency factors for the system under consideration. Parameters variation method, based on the solution obtained by symbolical method allows determine specific solution of the initial system of differential equations in the form convenient for the analysis. The obtained results may be of interest to organizations involved in the design of viscoelastic suspensions not only for caterpillar tractors, but also for road and air transport, and exploring emerging overload of cargoes in extreme conditions. According to the obtained results the conclusions on the expediency of operation of the hitch mechanism providing absolute rigidity of the coupling links of the tractor when moving on ground with periodic roughness in extreme operation conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Tomilin M. M. Crosstalk calculation in electric circuits of aircraft steering gear. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 137-144. Two types of electric drives — electro-mechanical or electro-hydrostatic — are supposed to be implemented for оnboard systems of “more electric aircraft” with a great number of various kinds of electrical equipment [1] for controlling various functional elements [2]. The increasing number of implemented electrical equipment, electro-mechanical steering gear in particular, which phase currents cause electromagnetic interference (EMI) in the form of electric and magnetic fields with high-level intensities. The main source of radiated EMI caused by electric drives systems are power circuits bundles. Electro-mechanic steering gear power circuits' bundles consist of a pair of twisted or axial conductors with currents' of tens of amps [5, 6]. Correspondingly, they generate radiated EMI, which may cause signal distortion in aircraft onboard system communication lines and, hence, deteriorate its functionality. The presented study is dedicated to of radiated EMI levels in the form of magnetic field harmonic components computation. These EMI are generated by phase currents in aircraft electro-mechanical actuator motor powering circuits, and crosstalk in the form of voltages in open conductors of double-wire communication lines. The presented spacing charts allow deduce that voltages and currents, which amplitudes are commensurable or even greater than valid signals values, occur in aircraft onboard cable system communication lines in the form of harmonic electric and/or magnetic field. The charts allow determining the safe distances between power circuits and open communication lines, wherein the levels of induced conducted interferences are significantly lower than information and control signals peak values in aircraft onboard system communication lines. It allows provide electromagnetic compatibility of high-power and low-power circuits. The presented paper is a part of the research work on computation and simulation of electromagnetic interferences, caused by transients in aircraft steering gear system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Le D. T., Averin S. V. Generation of vector PWM ensuring through currents elimination in three-phase bridge inverter. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 155-163. The рaрer suggests a control algorithm for voltage generation at induction motor windings by vector PWM. It reveals sрecifics of conventional vector PWM algorithm. Its is noted, that while through currents elimination with delay circuits a certain state occurs which allows identifying it as additional vector generation. The authors suggest a control algorithm with extra vectors generation as a through currents elimination technique. The рaрer comрares the suggested technique with conventional, and demonstrates that the develoрed algorithm using extra vectors allowed eliminate through currents of a first genus, decrease amрlitudes of high-order harmonics, and ensure рhase and рhase-to-рhase voltages рarameters similar to the conventional technique. Simulation of the suggested technique was carried out, and its results revealed that рhase current sine waveform could be ensured not only by increasing the number of generated vectors in one sector, but also by introducing extra vectors. Conventional and suggested techniques reveal that рhase and рhase-to-рhase voltages characteristics as well as рhase current are similar, but the number of high- order harmonics is less than with conventional one. The breadboard tests revealed that the develoрed algorithm did not lead to shaft whiррing. Inverter inрut current herewith is less relative to the conventional vector PWM technique. With on state of intermediate vectors significantly less than on state of base vectors the рossibility to attain рositive features рeculiar to the conventional technique, but eliminate a number of its drawbacks. The suggested technique, in рarticular, allows eliminate through currents, and gives more рossibilities of vector PWM imрlementation. Extra vectors on state duration control, rather than increasing the number of generated voltage vectors, allows ensure рhase current shaрe more close to sinusoidal. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voronin S. V., Loboda P. S., Ledyaev M. E. Optimal porous structure determination to improve aluminum alloy mechanical properties. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 164-173. Creating a competitive technology requires implementation of new materials with high specific mechanical properties. Conventionally, such materials are produced by introducing alloying elements, which form strengthening phases within the base metal structure. This approach usually results in the mass gain, because the hardening phase density is often higher than that of the base material. The mass of material can be reduced by introducing it into the volume of structural defects, such as pores. Due to high damping properties, low thermal conductivity, high sound-insulating ability and good moisture resistance, the porous materials are widely used in industry [1-7]. With existing porous aluminum, manufacturing technologies its strength properties decline takes place. However, with porous structure ordering the strength properties of finished products improve [8-10]. Thus, the goal of the presented work consists in improving specific mechanical properties, yield strength in particular, of the material by introducing orderly arranged pores. This study employed deformation processes finite element modeling with engineering analysis pack MSC.Marc to determine an optimal porous structure [11-12]. The study of porosity and a type of porous structure effect on mechanical properties was carried out with the following types of porous structures: square, field-interleaved, square with a pore in its center, triangle and hexagonal. With porosity of 0.4 to 0.5% porous samples FEM yield strength matching with compact material FEM samples yield strength is observed. With further porosity decrease growth of yield strength is observed for all types of porous structures. Maximum yield strength increase of 1 to 2% was achieved with porosity of 0.1%. The blanks for all the samples were cut from the aluminum alloy A5 sheet using laser cutting complex. All the obtained blanks were decollateв into three parts. The first part was left intact as a compact material sample. In the second part of the blanks, the ordered porous structure was obtained by laser burning. In the remaining samples, the porous structure was obtained with CNC milling and engraving machines with the drill diameter of 300 µm. The finite modelling and real uniaxial tensile tests results matching is observed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Agafonov R. Y., Vilkov F. E., Kasitsyn A. N., Predko P. Y., Marchenkov A. Y. Aluminum based alloys with rare-earth metals additives application for rocket-and-space engineering. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 174-180. Nowadays “AMg6”, “D16” and “AMn” aluminum alloys are traditionally used for space technology. Application of new advanced aluminum-based materials with of rare-earths additives instead of traditionally used alloys would enhance the electronic components protection from the space ionizing radiation due to alloying with high radiation absorbing elements. Whereas chemical composition manufacturing technique optimization will improve, alloys' mechanical properties compared to conventionally used, which will allow decrease weight and size parameters of the design. Tests carried out by Russia's space industry leading organizations revealed significant preeminence of new alloys compared to conventionally used with regard to protection against outer space ionizing radiation properties, and corresponding to them ability to chemical electroplating. Aluminum based alloys specific mass with rare-earth additives is 2.9 g/cm3 on the average. This paper is focused on the study of the three different alloying systems: 1 – Al-Dy-La-Cr-Zr, 2 – Al- Ce-Cr-Zr, 3 – Al-Mg-Sc-Zr-La-Ce; with rare-earths content not exceeding 11%, 7% and 9% by weight respectively. Each of the studied alloys, regarded as a material for spacecraft electronic equipment casing has a number of advantages and disadvantages. Increasing the rare-earth metals content in the alloy we can attain both better protective characteristics against space ionizing radiation, and aluminum based alloys with rare-earth additives welding properties improvement. Tough their density herewith will increase. Thus, it is necessary to pay special attention to improve mechanical properties of the basic metal and welding joints to prevent weight and size parameters of the design. Mechanical properties improvement with density reduction may, in some degree, be achieved by rare-earth aluminide phases' dispergating and increasing their density distribution in the alloy groundmass. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Betsofen S. Y., Osintsev O. E., Knyazev M. I., Dolgova M. I., Kabanova Y. A. Quantitative phase analysis of Al-Cu-Li-Mg system alloys. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 181-188. The authors have developed a method for computing a number of intermetallic phases (T1 and δ′- phase) of Al-Cu-Li-Mg system alloys based on measuring α-solid solution lattice periods; Vegard’s law, linking up solid solution lattice period value with alloying ingredients content in it, as well as chemical and phase content equations. Lithium content in solid solution serves herewith as variable parameter. Quaternary Al-Cu-Li-Mg system alloys quantitative phase analysis method is based on the assumption that all magnesium resides in the solid solution. This fact is considered by introducing the relevant term into equation for calculating the solid solution lattice period. This is the only difference fr om the previously developed similar method for ternary alloys Al-Cu-Li. The paper shows that the developed method can be effectively used for quantitative interpretation of thermal and thermomechanical processing impact on alloys’ phase content study results, as well as while Al-Cu-Li-Mg system alloys content optimization. This method allowed us to compute the relation between periods of solid solution lattice and the amount of intermetallic phases for 29 Russian and foreign industrial alloys of various generations. The paper reveals the existence of linear dependence of relative quantity of intermetallic phases in alloys from the atomic concentrations of lithium and copper (magnesium) in these alloys. It shows also, that relation between δ′-phase and ternary phases is determined by the atomic concentration of lithium and copper. The authors suggested new Al-Cu-Li-Mg — alloys classification, wh ere all alloys should be divided into five groups, differing from each other by the double δ’-phase and ternary phase shares , or ratio. According to this classification, all the alloys are divided into five groups. The first group includes Al-Mg-Li alloys, for which the phases ratio . For the second group the ratio varies from 2 to 3; for the 3rd group — from 5 to 7; for the fourth group — from 7 to 8, and the fifth group — from 11 to 17. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Soldatenko I. V. On titanium alloys semiproducts quality control. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 189-194. The goal of the paper consists in titanium alloys semiproducts macrostructure quality evaluation technique improvement. Active standard ten-point scale of macrostructures was developed based on – grains of strictly equiaxial shape specific to strain-free state of the alloy of sheet-like intragrain structure. It is well know macrostructure we can see only those structure elements, which size exceeds 100 –150 micron (i. e. the ones exceeding the eye resolution capability). Macro- and microstructure evaluation of a large number of serial semiproducts and laboratory samples revealed that not only – grains could be visible on a microstructure, but – colonies as well. It was established, that while checking a established, that the shape and size of the grains in the observed macrostructure depended on – grains and – colonies in the microstructure. Direct dependence of a macrostructure character from its microstructure was revealed. The paper shows that macro grain size and its tonality (degree of brilliance) depend directly on parameters of the microstructure, forming while deformation and heat treatment processes at temperatures of -or + – area. Correlation between the grain maximum longitudinal and diametrical sizes (the degree of non-equiaxiality – K) is clearly associated with physical degree of its deformation. This is another important parameter of macrostructure evaluation besides the grain size itself. By deformation, the macro grain tonality or its degree of brilliance changes together with the macro grain shape. Interrelation between degree of brilliance of a macrostructure under study and with its microstructure was established. The author suggests classify a macrostructure according to its tonality (degree of brilliance) by four types:
To improve titanium alloys evaluation objectivity and unambiguity the author suggest introduce quantitative estimation based on three parameters, namely grain size, and the degree of its non-equiaxiality and tonality. The next step to titanium alloys production quality improvement consists in working out requirements to macrostructure based on quantitative estimation of its parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Davydov A. D., Dianova E. V., Khmelevoi V. V. Fundamental and exploratory research priorities selection method. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 195-203. The paper suggests methodological approach to fundamental and research priorities portfolio forming. Such an approach is based on expert selection procedure. The authors formulated thematically oriented verbal and numerical scales for qualitative selection criteria groups. This criteria grouping is organized according to thematically similar features, significant while new perspective aircraft systems design. Due to the complexity of solved selection tasks it is reasonable to implement quality criteria system, described by 3-5 criteria groups with 3 to 7 criteria in each group. It allows convenient, transparent and comprehensive presentation of information to the expert in necessary and sufficient scale. Group-1 represents usefulness and importance; Group-2 represents resource intensiveness and resourcing, and Group-3 represents stability and manageability. With allowance for expertize complexity and supposed relative inconformity of experts opinions when evaluating significance of particular researches trends, we suggest selection procedure based on the Ansoff's theory of weak signals. Here, with allowable level of experts' nonconforming opinions, the individual opinions of competent experts with high estimate of particular FERs are taken into account. Here, core index (CI) and concordance index (DI) serve for the generalized selection measure. In this case we suggest FERs grouping in the following way. FER-1 are the trends with experts' high estimation by CI with high DI value. FER-2 are the trends with relatively high estimation by CI with relatively low DI values. FER-3 are the trends which CI is better than this for FER-2, with DI lower relative to FER-1 and comparable to this for FER-1. FER-4 represents such FER trends, which received consensus on lower importance, either special opinion was expressed by experts with relatively low authority. The authors suggested to form the portfolio not only by the trends with high CI and DI values, but consider FAR-2 trends (with priorities higher than this of FAR-3) as well. This approach allows us to identify and select among the priority research areas with potentially high efficiency, albeit with relatively high level of risk. The proposed approach also makes it possible to make informed decisions in a limited time based on authoritative (respectable) peer review. The method is oriented for use in decision support system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galkin V. I., Kuzina S. M. Building a model for optimal quantity determination of manufacturing facilities. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 204-210. The paper presents a technique for a number of work places optimization at the enterprise with variable product release program. The developed technique is based on simulation and experimental design. The paper considers the operation of the enterprise manufacturing several kinds of products by assembling either purchased components or produced at this enterprise. The simulation model developed in the course of this study allows build and optimize manufacturing resources under various variants of enterprise's target figures. The model was built with AnyLogic program, which allows specify time intervals at every stage of manufacturing either major product, or associated items. There is a possibility to model the situation with various number of assembling departments. Based on the built model the authors carried out the optimization experiment, which allows compute an optimal number of equipment for the specified work-order quantity for all types of products. The paper suggests goal functions with productivity optimization. Using this instrument the results for each experiment were obtained by varying values of run-out production plan. It is found on what production volumes minimum quantity of equipment is optimal, and at what moment the number of working places should be increased. It is also determined that maximum possible quantity of equipment under specified production volume boundaries is not necessary. The obtained results were processed according to the experimental design technique. The equation for corrected production effect computation as function of a number of assembling departments and products production volume. The proposed method is universal and can be applied for various types of production. The developed technique can be used as one of the instruments while developing the system of managerial decision making. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Efimova N. S., Zamkovoi A. A., Titkov A. M. Aircraft manufacturing enterprise innovative activities development with allowance for economic security requirements. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 211-217. At present, creation and implementation of a system of indicators for monitoring R&D processes is necessary, since the degree of highly efficient estimation of economic security of an enterprise, and formation of economic mechanism implementing the complex of necessary measures on prediction and preventing a danger, corresponding to the scale and threat environment to aircraft industry in the aggregate. The main objective of the innovative activities economic security level consists in timely analysis and monitoring of a complex indicators system, inclusive aircraft industry specifics. Development and implementation of economic mechanism for innovative activities economic security provision in aircraft industry will allow reveal: insufficient certainty of a forecast at various R&D fulfillment at stages; excessively enlarged and averaged character of labor intensity rate and expenditures, new objects' operational service norms, reliability and durability; insufficient comparability of new objects with selected prototype objects, or the lack of scientifically substantiated techniques for this comparability economic evaluation while effectiveness indicators computation; the lack of exact information on all spheres of R&D results supposed implementation and their scope of their implementation; the difficulty of extracting the share of economic effect related to this particular technical solution, the specified object, used as a constituent part of a more complex technical system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chaika N. K., Gavrilova I. S. Corporate governance system development estimation method. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 218-224. A corporate governance system developing method is offered within the framework of this paper. This newly developed method aims at estimating the corporate development level of a space-rocket industry enterprise, as one of the crisis-proof enterprise governance tools. American and German corporate governance models are distinguished as the most popular models. Russian corporate governance practices are equally distant ideologically from both. To analyze the corporate governance system at the rocket-space industry enterprise the authors developed their own estimation method, consisting in accounting for a number of specifics of integrated structures and individual enterprises functioning. Basic methodological approaches to optimal assessment method of corporate governance system development at the enterprises and integrated structures of rocket-space industry are considered. The developed method account for specifics of the companies and allows carry out their comparative assessment in conditions of differences in structure, scope and lines of activity. This method represents a multilevel assessment system by two blocks — the level of corporate governance implementation and the level of the corporate governance system formalization. In accordance with the results of the study, the authors obtained the optimized branch method of estimation of the level of corporate governance system development in the interests of crisis-proof management. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Omel'yanovich M. Y. Deepening financial inequality: causes and consequences. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 225-235. This paper is dedicated to the study of economic relations associated with socio-economic inequalities and its component — financial inequality, which is reflected at the global, state and regional levels, as well as the levels of enterprises, organizations, institutions and individuals. In modern conditions financial inequality worsened dramatically with the development of the world economy, deepening of global economic relations; development of financial relations; strategic amalgamations between corporations, alliances, unions; deepening of contradictions between rivaling states; globalization; labor mobility, goods and services; formation of a unified information system. The goal of the paper consists in emphasizing the importance of financial inequality as an economic phenomenon, analyzing its dynamics, developing recommendations on its mitigation and implementation of State regulation by using aggregate financial instruments, such as budget, taxes, public debt, etc. While carrying out the studies and tis paper formation the author employed scientific methods of analysis and synthesis of theoretical views and concepts, economic and statistical methods to assess the impact of various factors on the financial inequality, as well as scientific heritage on this issue. The study was conducted based on the principle of historicism. Economic theory principles, scientific concepts and theoretical evidence of national and foreign scientists served as this work methodological basis. The results of the work consist in generalization scientific ideas and viewpoints of national and foreign scientists and economists, and determining socio-economic inequalities as inequality of wealth associated with the degree of realization of human rights, democracy, free market and effective State laws. Theoretical research, opinions and viewpoints contained in learned writings on the issue of financial inequality will supplement the content of academoic disciplines related to “Finance and Credit”, taught to students of higher professional education. The results of the study, based on analysis of financial statistics on income, inflation, taxes, debts, are rather efficient at the macro-level while forming the state policy. The results obtained in the course of the study are aimed at State regulation of financial inequity mitigation through implementation of fiscal measures to the social protection of the population. The state support during economic crises and the need for economic regeneration will affect significantly the financial inequality mitigation. The paper suggests creative destruction of informal relations dominance, transparency of state accountability, formation of a balance between State regulatory effects on financial inequality and self-regulation on the part of businesses and individuals. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuznetsov P. A., Stepanov O. A. Combined system for electric power consumers protection against emergency states. Aerospace MAI Journal, 2016, vol. 23, no 4, pp. 145-154. The main issue of this article consists in analyzing the main electric network emergency states and to designing a protective system model, which is able to minimize or fully avoid their aftermath. The results of failures analysis at various power plants and installations allowed separate out the basic types of emergency operating modes. They include sudden voltage dropouts, voltage waveform fluctuations (flickering), rolling blackouts and presence of significant reactive power abundance in a power grid. The rolling blackout presents the greatest danger due to its aftermath. The analysis of emergency modes occurrence revealed that most commonly they arise due to insignificant event, leading to avalanche-type emergency growth. This fact is reflected in the presented algorithm. Moreover, most commonly, these emergencies can be eliminated with the timely reaction of the personnel. However, as the practice indicates, these specified nonsignificant factors were ignored by maintenance staff. Two-level of consumers' complex protection model for emergency elimination and its aftermath mitigation is suggested. Both parts are autonomous and can be set separately, or in conjunction. The first part of the system is responsible for the reactive power compensation in the power grid. It differs from the existing prototypes by smaller size, cost and asymmetric structure for reactive power compensation in wide range. The paper presents voltage and power balance graphs at the object before and after compensation. The presented data proves that implementation of such installations allows reduce rolling blackout occurrence probability. The second part of the system represents from rolling blackout protection controller, which, in case of any power grid section overload, or voltage dropout, analyses the states of consumers and turns off those of lower priority. This helps avoiding entire system cascaded failure occurrence. The presented system both as a whole and in separate parts presents interest for industrial electric energy consumers from the viewpoint of spoilage minimization occurring due to power grid failures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Romanova T. N., Paschenko O. B., Gavrilova N. Y., Shchetinin G. A. Dynamic object multidisciplinary parameters optimization engineering method. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 7-14. This work aims at developing a dynamic object multidisciplinary optimization, namely maneuverable aircraft horizontal empennage. Horizontal empennage is a complex technical system with a great number of parameters described by the equations belonging to various scientific disciplines. Thus, the developed method represents a multidisciplinary optimization method. The efficiency of the horizontal empennage can be evaluated by the value of the moment produced by the horizontal empennage and the pitch moment gradient magnitude, which can ensure the aircraft balancing and performing a specified maneuver. Parameters necessary for optimization in the framework of the specified problem were determined and their ranking was performed by weight factor determination for each parameter. Then the goal function for horizontal empennage parameters optimization was created. Various approaches to supersonic aircraft horizontal empennage parameters optimization, such as method using Pareto principle, or method using Hurwitz criterion, were studied and realized. Analysis of operation of the above mentioned optimization methods in the context of the specified problem revealed their insufficient efficiency. With the aim of improving the obtained results a new optimization method was developed and suggested. This method employs the valuation of several valuation functions to obtain optimal solution. The effectiveness of the developed method is demonstrated using various input data sets, and the effect of various weight factors parameters on obtained result was studied. Its operation results in horizontal empennage optimal geometric parameters, formed automatically with CAD system Siemens NX 7.5 “Modeling”. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kruchinin M. M., Artamonov B. L. Analysis of hinge moments occurring on helicopter main rotor blades . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 15-20. The paper considers computational results of moments relative to main rotor axial hinge caused by action of inertial and aerodynamic forces occurring on the blades. The computational method is based on the generalized disk vortex theory of rotor in an oblique flow in its most simple version, when the air load over rotor disk is assumed constant in computing inductive speed vector components. Flapping movement coefficients of hinge-suspended in thrust plane rotor blades are defined by analytical relations with an accuracy to the first harmonic of Fourier series. This assumption reduces the problem of hinge moments calculation with specified rotor control law to the method of successive iteration on thrust force ratio. As an example, the authors considered the rotor blades operation of helicopters Mi-34 and Mi-28. They studied the change of hinge moment value depending on the blade azimuthal position, and evaluated each components contribution to it. The wobble plate rod strain dependence on flight speed, blade angles and control action was analyzed. It was established that with wobble plate ring deviation in forward longitudinal direction law of azimuthal strain variation demonstrates harmonic character with pronounced maximum near the retreating blade. With wobble plate ring deviation in transverse direction the similar dependence is of the same character, but its amplitude is negligible compared to longitudinal control. Calculations were executed for helicopter main rotors with various structures of a hub and blades. The results were compared with experiments and calculations of the other authors. It is shown that mathematical model of absolutely rigid blade combined with disk rotor vortex model allows evaluate control system loading level at various helicopter flight modes with adequate accuracy. The ways of model improvement allowing define the obtained results more exactly are outlined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bibikov S. Y., Katkova E. A. Methodology of air intake channel integration into aircraft layout using Unigraphics as the geometric modelling environment. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 21-28. The article depicts methodology and gives recommendations on complex geometry air intake modelling process on the example of uncontrolled air intake. These recommendations have been elaborated considering many requirements and suggest the procedure, which could be used during air intake channels integration into aircraft layout. Main requirements to the geometry (equivalent angle of subsonic diffuser) and relative length (Lch/Dent, Lch — channel length, Dent — diameter of engine entrance), as well as parameters of air intake entrance channel are imposed after all boundary conditions, such as air intake input square (F0), air intake throat square (Fth) and optimal graphics of air intake duct squares are set. The suggested method for deceleration system integration allows the transfer to intake duct surface constructing with minimum iterations. The practical part of this work includes recommendations to construct optimal complex duct surfaces using “Unigraphics” with allowance for their maximum optimization. We suggest to use “dynamic changes” method while designing air intake, i. e. changing associative construction with construction parameters changing (shape-generating parameters). Based on created geometry we plot the graph of air intake duct squares according to the squares obtained duct cross sections. It allows demonstrate the dissimilarity of actual duct geometric parameters from the presumed (optimal). The above-described procedure allows select air intake and air duct location of supersonic jet with allowance for a large variety of layout limitations and gas dynamic requirements. It allows integrate air intake ducts of complex space form into aircraft layout under development with minimal time consumption. The suggested procedure of “dynamic” air intake duct geometry changing allows control changes of its geometric characteristics (graph of air intake duct squares function) and select thereby the duct parameters with subsequent optimization. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Anisimov V. M., Orlov M. Y., Zubrilin I. A. Computational evaluation of annular combustion chamber flame tube walls stress-and-strain state. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 29-39. The important goal of GTE combustion chambers and installations design and workout consists in provision of the specified durability and reliability. In response to this problem, the temperature of the combustion chamber major elements should stay within the operating temperature range of their structural materials, and their deformation should not exceed the specified values. Combustion chamber flame tube walls are some of the most heat-loaded elements. Thus, the problem associated with the study of their stress-and-strain state is particularly up-to-date. It is worsen by the existing tendencies aimed at increasing compression ratio of the compressor and gas temperature at the turbine input. Temperature distribution over compressor flame tube surface determining in the course of complete product bench testing presents a complex task. The effective method of rectifying the above said problem during gas turbine units consists in numerical modeling methods implementation, which requires developing procedures of their implementation. Such procedure was developed while GTD combustion chamber for terrestrial surface application design. For its realization we used geometrically conjugate 3-D model of the combustion chamber, including both air-gas channel necessary for gas dynamic processes modeling, and flame tube walls with multilayer thermal-protective coating for heat transfer computation. Combustion chamber operating procedure mathematical model was developed earlier and passed validation process. Simulation was carried out in ANSYS. Temperature distribution on the flame tube wall was obtained by computation. Based on the analysis of the obtained results we managed to reduce maximum flame tube wall temperature to the required value at the expense of apertures areas redistribution between cooling system strips. Stresses and deformations occurring due to flame tube walls heating were determined as well. It was revealed that maximum stress occur at cooling apertures locations. The value of calculated strength factor equals 2.7. The developed procedure for combustion chamber flame tube walls thermal-and-stress states determination can be implemented for various combustion chamber desings, materials and multi-layer walls. This procedure allows predicting the most dangerous temperature zones on the flame tube walls and burn-out in this zones prior to bench testing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zvonarev S. L., Klyagin S. V., Potapov A. Y. Study of dual-shaft gas turbine engine inter-rotor bearing vibrations at slow rotor rotation . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 40-46. The purpose of this work consists in clarification and generalization of two-shaft gas turbine engine rolling bearings vibration diagnostics method. The paper gives the review of the well-known problems associated with gas turbine engine rolling bearings vibration diagnostics, and considers methods employed while carrying out diagnostics. We sel ected the procedure using hand rolling of one of the engines' rotors for our studies. The paper considers possible problems occurring during diagnostics. For the studies we assume the same frequency range that is used while hand rolling. The vibration signal measured prior to the complete stop of the engine is generated under identical conditions. Such conditions are characterized by very low forces, causing forced oscillations. Thus, we can neglect these oscillations. The signal for the study carrying out was obtained fr om the engine with damaged bearing. The degree of the damage development was rather high. The rotor decrease in speed, and short time interval do not allow employ conventional rolling bearings spectral vibration diagnostics methods. Analysis of the signal temporal realization reveals the absence of considerable shock load. Spectral analysis reveals the presence of only one significant harmonic in coincidence with the engines natural frequency. this natural frequency is characterized by the high value of deformation latent energy accumulated in in the bearing. The absence of the shock load points out that natural oscillations excitation does not occur. The inference is drawn on the presence of self-sustained oscillations in rotor rundown mode, developed at natural frequency. As long as the oscillating processes in the engine are almost finished, the natural oscillations cannot obtain energy for the amplitude rise. In view of natural oscillations amplitude smallness their impact on bearing degradation is insignificant. Self-sustained oscillations process phase diagrams are plotted. Strap brake is a literary analogue of the being obtained self-sustained oscillation system. Despite the vibration signal non-stationarity, spectral analysis allows obtain reliable diagnostic results. The conclusion has been drawn about the possibility of applying the considered phenomenon for vibration diagnostics of roller bearing dual-shaft gas turbine engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lanskii A. M., Lukachev S. V., Kolomzarov O. V. Small gas turbine engines combustion chambers geometriс resizing and integral parameters changing trends. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 47-57. The article considers the development of small gas turbine engine combustion chamber draft design. Though it occupies relatively short period of time, it is an extremely important element in reference to the engine lifecycle period. The draft design results allow obtain all necessary information about both the combustion chamber as a whole and its constituent parts. The small-sized gas turbine engine combustion chamber draft design allows determine its shape and the features of its embodiment. Geometry selection and integrated parameters evaluation with account for turbocharger components composite action is important due to incomplete information on these matters. The paper presents the results of the statistical data processing of geometric parameters and integral characteristics of the GTE combustion chambers. Complex correlation functions were obtained by methods of mathematical statistics. Correlation functions describe the structure and geometry: primary zone operating parameters and combustion chamber integral characteristics such as: flame tube volume (VFT), relative length of flame tube(LFT/VFT), nozzles relative pitch, combustion efficiency, residence time, forcing coefficient (KV), thermal factor (QVP) and relative areas of internal and external channels. Changing of the abovementioned values depends on consumable complex (GCC). Table below presents results of the statistical data processing. Most coefficient of determination values lay within the range of 0.06 to 0.7. Not all of the dependencies have high coefficients of determination. However, this does not exclude the possibility of their use in the preliminary assessment of the gas turbine engine combustion chambers structural and integral parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Finogenov S. L., Kolomentsev A. I. Parameters selection of solar thermal rocket engine under flight time limitation. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 58-68. Solar thermal propulsion (STP) is considered as means of inter-orbital transportation from low Earth orbit into geostationary orbit. The payload insertion time for conventional STP usually equals approximately 60 days. STP contains high-temperature concentrator-absorber system (CAS) as a power source, with possibility of using multi-staged absorber of non-isothermal type with higher optical-power efficiency. Ballistic efficiency of the upper stage with STP grows with the increase of extent of CAS not-isothermal properties and can exceed 1.5-2 times the efficiency of liquid propellant rocket engines (LRE). Ballistic efficiency of upper stage with the STP is determined by relevant parameters of the CAS, to which we can assign concentrator accuracy parameter and hydrogen heating temperature in CAS, as well as permissive conditions of CAS's sun orientation. Selection of CAS expedient parameters can be realized, in some cases, different from those optimal with allowance for technological limitations under permissible reduction of ballistic efficiency of solar upper stage compared to LRE implementation case. Considering that transportation system, employing combination of high and low thrust engines with adequate insertion time of 60-120 days may compete with STP as inter-orbital transportation system, it is expedient to estimate the ballistic efficiency of solar upper stage at lower flight time. The problem simulation demonstrates the capability of reducing the payload injection time to 20...40 days at high ballistic efficiency of solar upper stage (in case of extreme non-isothermal multi-staged CAS, the payload mass is twice higher compared to LRE). STP optimal relevant parameters herewith change towards CAS simplification. The CAS Sun tracking conditions also become simpler. STP optimal parameter values for various time intervals of inter-orbital transfer are presented. The possibility of providing high ballistic efficiency at the flight time of 20-40 days with STP implementation with non-isothermal multi-staged CAS, compared to the transportation system employing combination of engines of large and low thrust, is shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churkin V. M. On evaluating load aerodynamic effect on free oscillations of parachute system with pivotally suspended load . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 69-76. The paper considers parachute system with pivotally suspended load movement in vertical plane. When deriving the equation of motion the parachute system is presented as a mechanical system consisting of two solid bodies connected by ideal linkage joint (deadeye), i. e. parachute and load. Parachute system free oscillations analysis is carried out with the equations of the simplified disturbed motion model, where translational movement with constant speed and constant parachute canopy and load incidence angles. As partial movement mathematical model the equations of first approximation system are accepted, and the sought non-linear model is obtained by substituting in these equations normal components of parachute canopy and load aerodynamic forces coefficients linear dependencies from their incident angles by non-linear dependencies. The dependency of parachute canopy aerodynamic force normal component from its incidence angle herewith takes the form characteristic for the case when canopy fabric has low permeability. After harmonic linearization of these non-linear dependencies the thus obtained system of non-linear equations for simplified non-linear model falls into two systems corresponding to constant and variable components of the sought solution. Equations linking amplitudes and center displacements of the sought oscillations are derived from the equations containing constant components, while equations linking amplitudes with oscillation frequencies and inequalities, determining stability conditions of the sought oscillations are derived from the equations containing variable components. Implementation of the suggested procedure of parachute system with pivotally suspended load with allowance for aerodynamic load is illustrated by numerical example. The boundaries of canopy incidence angle initial values that provide damping oscillations mode of the considered parachute system near the specified unperturbed motion are determined with or without considering the load aerodynamics. To evaluate the results of theoretical calculations the paper presents the results of numeric integration of the initial equations of the parachute system movement. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tatarenko D. S., Shutov P. V., Efanov V. V., Rogovenko O. N. Uncontrolled objects ballistic characteristic calculation technique . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 77-83. The paper considers the current state-of-the-art of uncontrolled axisymmetric object throwing together ballistic support, and analysis of the existing techniques for their trajectory calculation when launched from an aerial vehicle (AV). The main parameter specifying uncontrolled object motion relative to the center of mass is nutation angle δ , which initial value can achieve the threshold values (abou δ0= 30°) and depends on combinations of its projection, such as angle of throwing λ0, separation velocity, environment disturbance, launcher vibration etc. To improve accuracy of the problem solution aboard an AV, we suggested to use full ballistic motion model during its separation from the carrier, and the initial conditions to solve it could be obtained according to the ballistic characteristic determination technique of uncontrolled objects being offered. This technique can be implemented under condition of availability of testing system, which make-up and structure are presented in the paper. Main advantage of the testing system is implementation of proximity sensors comprising a set of sectors realized in the form of perpendicular arranged rows of photo-detectors and radiating elements. The paper presents for uncontrolled object motion trajectory with initial nutation angle computation results, which show that when throwing 30-millimeter uncontrolled axisymmetric objects rotating about its axis with initial nutation angle values not-to-exceed 10° to a range of 1500-2000 m, the range spread up to 170 m and lateral deviation spread up to 20 m are observed. In range environment, the proposed technique for ballistic characteristic determination of uncontrolled objects enables to obtain dependences of initial uncontrolled object nutation angles versus different conditions of their launch. The resulting experimental dependences can be utilized to obtain accurate initial conditions required when integrating differential equations of full ballistic motion model for uncontrolled objects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Trinh V. T., Nguyen N. M. Realization of passenger plane auto-land desired trajectory shaping algorithm based on anthropocentric principle . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 84-95. The paper discusses the issues of pilot's dynamics detection and its accounting in the process of glide-path capture accuracy appraisal, as well as accounting pilots dynamics effect on aircraft precision of movement while glide path movement and flaring-out. We suggest solving these issues based on complex mathematical modeling. The pilot’s behavior based on representing the pilot as an optimal non-linear regulator, and experimental data search of generalized criterion of pilot’s control activities were considered in details. The obtained formal criterion with derived weight factors enables realization in ACS the algorithm identical to pilot’s control activities while aircraft piloting in the form of a direct problem of getting from an arbitrary point in airdrome area on approach glide path. Three types of stages of landing and corresponding pilot’s models, such as glide path capture, movement on the glide path, and flaring-out before runway touchdown. Modeling and algorithmic analysis of various aircraft thrust control laws allowed selecting the most expedient altitude of flaring-out starting on the assumption of flaring-out altitude valuation permissible error maximizing principle. The obtained permissible areas of initial flaring-out altitudes provide maximum pilot’s comfort in case of forced manual landing mode transition. The aforesaid solutions enable desired trajectories shaping and algorithms realizing automatic landing according to anthropocentric principle, providing, if necessary, fast transition to manual control mode in case of automatic control rejection, adapting to the current situation. Anthropocentric approach allows the pilot to operate under minimum psychological tension, since while automatic control he observes the movement, which he would realize himself in case of the necessity of manual mode transition. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolaev A. V., Pashko A. D. Active protecting elements cast ballistic support while small-sized high-speed objects operation . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 96-101. The article analyses the state-of-the-art of aviation guided missiles development. Today guided missiles guidance systems thermal imaging coordinators have widespread application. Reading units with digital image processing and fiber optics gain maximum acceptance. The problem of guided missile neutralizing at a safe distance from the defended aircraft was solved. An approach allowing increase the safety of a defended aircraft through ballistic support of active protecting elements casting was considered. This method employs the automatic ejection unit allowing ejection of active protecting elements in the required direction. Furthermore, the on-board information systems, computer, mother ship measurement sensors and ejecting unit are integrated into unified complex. A model of active protecting element movement for on-board ballistic algorithms synthesis was created. It allows develop mathematical tools defending complex dataware while active protecting elements implementation, scientific and methodological tools for their effectiveness evaluation. Rational implementation of active protecting elements as a part of aircraft system was substantiated. The developed algorithm allows realize the conditions of active protecting element implementation in real technical applications, operating within the aviation system. While determining the parameters of guided missile movement relative to an aircraft, the trajectory of the rocket movement was predicted according to the guidance mode employed by the missile. For this purpose the guidance system obtains the information on coordinates and other aircraft and missile movement patterns at every time instant. It sets the character of their interrelation, determines the degree of this interrelation disruption. Based on this information it forms the parameters and control signals, providing the required movement of a rocket to an aircraft. Using navigation and weapon-aiming system computing capabilities, together with on-board defensive systems the time of a missile closing-in with and aircraft was computed. Ballistic model of active protecting element casting ensuring its encounter with a guided missile was developed. The result of the algorithm operation provides neutralizing of a rocket in the air, thus preserving an aircraft performance ability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Maximov N. А., Skleimin Y. B., Sharonov A. V. Bundled software for unmanned aerial system flight trackdevelopment while its re-deployment to operating zone . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 102-111. The paper presents the bundled software meant four wheeled off-road vehicle convoy itinerary selection, while unmanned aerial system (UAS) re-deployment from the deployment site to operating zone. The main feature of this bundled software consists in the possibility of its use not only for road travel, but also in the possibility for travel the part of the route on a country road and off-road. The performed analysis revealed that it is expedient to select easily realized algorithm as the theoretical basis, such as Dejkstra algoritmh, as well as Floyd-Warshall algorithm and Bellman-Ford algorithm. UML models of the system under development were constructed. The paper presents the test example of forming characteristicsof transport means constituting the convoy. It allowed determine for each road layout sector its negotiability by the convoy and the convoy travel time along the sector, using the built-in calculator. The authors used simplified computation algorithm to calculate route sectors negotiability parameters and the speed (time) of their passing those sectors. Then the negotiability of a certain sector was determined. Finally, a graph of roads negotiability was plotted. The shortest distance between the UAS locationoriginand redeployment destination point is searched on the plotted graph. The developed automated information system allows: — Reduce transport means movement constituting a convoy moving off-road route planning labor intensity due to automation of the majority of operator's functions; — Increase the quality and accuracy of calculations, needed for road layout graphanalysis; — Reduce the personnel, necessary for execution of work on UAS convoy movement planning, costs; — Obtain up-to-dateaccountingon variousUAS movement route measures of efficiency in real time mode to take managerial solutions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolaev E. I., Pantyukhin K. N. Helicopter dynamic stability in the ground spin-up mode with allowance for blades flexibility . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 112-120. The study of helicopter dynamic stability is associated in most cases with such a phenomenon as ground resonance, which presents helicopter self-oscillations with increasing amplitude. The origin of this swaying consists in interaction of blades oscillations relative to the hinges, vertical in particular, with helicopter body on chassis oscillations. Since helicopter presents a complex mechanism, assumptions and simplifications allowing saving computing resources and with sufficient accuracy easily correlated with the experiment were introduced while mathematical models building. At present, a researcher possesses considerable computing resources. Thus, one can afford building much more complicated models, allowing solving the problem of «ground» resonance computation in more detail. The paper presents helicopter mathematical model, which body has six degrees of freedom, and flexible blades with three degrees of freedom in the attachment point to the hub. Helicopter alighting gear (chassis) is presented in the model by flexibility matrix. Helicopter equations of motion were obtained using second order Lagrange equation, and blades flexural oscillations equations were obtained with widely known Galerkins method. Flexible blade mathematical model considers only the first three forms of hinges flexure-flexure-torsion oscillations. Following the above-described mathematical model the complex of programs was developed using Maple and MATLAB. Within the range from zero to main rotor operating speed computation of helicopter dynamic instability zones on the ground was made. Comparison of the results obtained by R. Coleman method and mathematical model with rigid blades for ANSAT helicopter revealed sufficient convergence. Mathematical models with rigid and flexible blades developed by the authors allow determine additional instability zones. The model with flexible blades allows revealing a number of additional instability zones, which may have great significance. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vereshchikov D. V., Kuznetsov A. D. Justification of military transport aircraft control automation in conditions of heavy cargo airlift delivery . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 121-128. Heavy cargo parachuting off an aircraft is the fastest wat to deliver it to the uttermost remote and hard-to-reach areas. However, the pilot faces difficulties steering an aircraft while discharging a heavy cargo, due to the aircraft center of mass considerable changes. This problem aggravates now for several reasons. Firstly, the weight increase of heavy cargo, armored vehicles in particular. Secondly, the increase of speed range and dumping heights. The possibility of an “air start”, i. e. a spacecraft airplane launching at high altitudes, as well as rescue vessels air drop is considered. A free drop from deck levels of 5 ± 2 m is rather difficult due to the earth immediate proximity. The possible solution to the piloting complexity problem consists in automation of this process. It is necessary to justify scientifically and methodologically the need and possibility of an aircraft control automation while heavy cargo extraction. Thus, the object of the study is the process of aircraft control while a heavy cargo extraction, and the subject of the study is its automation. The research task are as follows:
The need for flight control automation was proved based on the study of the MTA flight parameters violation of operating limitations while heavy cargo extraction and consideration of the factors affecting this process. The results of the analysis of the existing ways of the abovementioned problem solution and possible ways of flight control automation allowed develop adaptive control algorithms for aircraft control while heavy cargo extraction. It must be emphasized, that the detailed analysis of the abovementioned problem and rational ways of its solving under modern conditions were made for the first time and, furthermore, it seems expedient to carry out further studies on developing the automation technique based on adaptive algorithms with current identification. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gelvig M. Y. Aircraft pilot outside world view charting technique . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 129-135. Sufficient outside world view fr om pilot’s flight station is one of the essential conditions of the safe and comfortable aircraft piloting, including a helicopter. Horizontal and vertical look-up angles from the basic directional point C explicit numerical values are specified by regulatory documents, and by FAR-29 Aviation regulations in particular. The viewing field (VF) is usually represented for clarity in the form of chart , plotted in rectangular coordinate system, wh ere and are respectively vertical and horizontal VF angles. Openings outlines presented in rectangular coordinate system should closely comply with normative chart. Conventional view assessment methods, including measuring ones (in-situ and virtual with 3D-model), are considerably labor consuming, as they require a lot of measured results manual processing. Besides, with the input data alteration (such as basic directional point C position) all measurements must be repeated. The previous effort of this problem solution automation by means of 3D CAD Solid Works system resulted in successful graphic solution of VF plotting in polar coordinates. However, geometry conversion to rectangular coordinate system with the CAD system failed. To that end, an algorithm employing specially designed software was implemented. It led to the desired result. Nevertheless, the complexity of such solution makes this technique implementation quite a problem. The objective of the effort presented in the paper was the outside world view VF plotting graphic technique with only basic 3D CAD system available in the Company. The most challenging task while this technique developing was geometry convertion from polar to rectangular coordinates. This problem was solved in CAD NX 8.5 by successive projections on auxiliary vertical and horizontal cylinders with subsequent unfolding of these projections on plane. As a result, we have obtained a field of vision plot in rectangular coordinates. All constructions are fully associative. With input data alteration, the geometry reshapes automatically. We managed to solve the problem of normative field of vision boundaries on the crew cabins’ surface determination, based on reverse projection combinations VF normative field of vision boundaries convolutions in rectangular coordinate system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalevich M. V., Goncharov A. V., Gukov R. Y. Titanium alloys cylindrical components unevenness during pneumo-thermal forming. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 136-142. The main goal of the paper is determination the dependency of maximum thinning of the material from geometrical parameters during pneumo-thermal forming (superplastic forming — SPF) of various standard forms. This paper describes the data, obtained by studying the cylindrical shape components formation. To solve this problem, mathematical simulation of cylinders of various configurations of alloy VT20 was made with PAM STAMP 2G software package. The simulation was performed for the groups of cylinders with radius of R = 50 mm and thickness of S = 1 mm, and with radius of R =80 mm and thickness of S = 2 mm. The results of the simulation are presented by S’R’ diagram for various H’ values. The lines were constructed using linear approximation, and coefficients “a” and “b” were obtained for approximate lines. Also graphs a(H’) and b(H’) were constructed. Substituting the obtained values of coefficients a(H’) and b(H’) in the of the line equation, approximate expression was obtained for estimating minimum wall thickness for AMg6M alloy cylinders with R = 50 mm, R = 80 mm and cylinders with R = 80 mm from. As it is seen from the dependencies, these coefficients are approximately equal, which allows us to extend this dependency to other group of cylinders. The dependencies were tested with AMg6M alloy. Component thickness was measured by ICH-10 indicator. The experimental and simulation results revealed good convergence. After the cylinder simulation results analysis, recommending cylinder forming selection graph, depending on the required thinning [S/S0] Ч 100% was developed. This graph presents the recommendation for designers and technologists. Its main purpose is to simplify the design of components with optimal mass characteristics. The knowledge to what relative parameters area a component belongs would sate the design time. Thus, the following ratios for cylindrical components are considered optimal: 1. For zones with thinning greater than 78%, better apply molding or drawing. 2. For zones with thinning of 45-78% (0,1 < H’ < 0,75 и 0,05 < R’< 0,7) the best optimal solution SPF technology implementation. 3. For zones with thinning of 25-45% the better solution is to use pre-stretch for set of material from flange zone with following pneumatic forming. For zones with thinning of 16-25% (for components with H’ > 0,8 and R’ < 0,5) SPF technology implementation is not advisable. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov S. B., Syroezhkin E. V., Kharchenko I. A. Combined power-supply systems based on reversible rotary and static converters for Fully-Electrified-Aircraft. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 143-154. The realization of so-called “Fully-Electrified-Aircraft” concept (i. e. without any on-board air-powered and fluid drives) assumes a significant power increase of on-board main electric generator (up to 500 kW per a single power installation with two build-in high-speed generators). Up to date, cascaded-synchronous generators with brushless electromagnetic rotor excitation from synchronous cross-field exciter through uncontrolled rotating rectifier-exciter were traditionally used as the main electric generators (including starter-generators) with capacity range from 30 kW to 250 kW. Their essential drawbacks are as follows: – low reliability and significant rotor excitation system time lag; – structural complexity of salient-pole rotor design; – relatively small starting torque in starter (asynchronous) mode;
The cascade generator without constant rotary speed driving gear replacement by magneto-electric generator (with rotary permanent magnets) leads to the following complications:
– The necessity of implementing fast powerful emergency releaser on the drive shaft to provide armature-coil short circuit protection; – Significant structure oversize due to winding coil isolation strengthening with relatively high rotation speed to armature EMF ratio (more than 2-2.5);– The necessity to install a full-size (with respect to power) armature circuit static voltage regulator. Due to power pulse electronics as well as static power converters digital control systems development the electrical motor starter-generators without constant rotary speed driving gear alternative appeared, namely, asynchronous starter-generator with self-excitation in generating mode within small sliding range over armature circuit via high-performance transistor controlled sine- wave voltage inverter. With that, the excitation power in armature circuit (with insignificant sliding value up to 5-7%) is relatively small.The following positive moments should be taken into account for such alternative justification:
The last of the above-listed factors has significant limitations. That is why combined AC-DC power supply systems without constant-rotary-speed-driving gear assume usually parallel operation only for the channels with DC (rectified) voltage (270 V or 540 V) irrespective of the types of main generators. With such local sub-systems integration into common centralized power-supply system (270...540 V) with high specified total power (up to 1 kW) provides high quality electric power both in static and dynamic (transitional) modes. It seems a reasonable try to realize a trade-off (at least at the present time) combined system for AC-DC higher voltage power-supply system with separate main channels of higher power generating and distribution subsystems of three types fixed in the Russian State Standard “P 54073-2010”: 1) three-phase unstable (“floating) frequency AC voltage: 115/200V or 230/400V, 360-800Hz; 2) higher DC voltage: ± 270V or ± 540V; 3) three-phase stable frequency AC voltage: 115/200V or 230/400V, 400 Hz. As to separate classic backup low-voltage ( ± 27 V) DC power-supply sub-system with rechargeable battery regulated by Russian State Standard for low-voltage power consumers as well as backup electric-motor and/or convertor-invertor transducers — its presence, surely, is provided with any power-supply system version. While designing up-to-date high-performance on-board electronic and electrical system distinguished by their weight-dimension, reliability, value and operation- economical parameters the preference should be given to a unified modular power-scalable architecture. At that, the best effectiveness is obtained under corresponding circuit design selection for equipment modules with reversible (bidirectional) conversion, such as, buck/boost reversible switched mode converters (direct or transformer versions – 270/27 V); reversible rectifying-inverter converters with power factor correction (115/200 V – 0 ± 270V), reversible frequency converter (360...800 Hz/400Hz) and the others as well as multifunctional pulse converters. These preferences provide rather flexible adaptivity in various units, devices, assemblages and sub-systems upgrading. AC-DC combined power-supply system structures based on reversible electric-machine (starter-generator and engine-compensatory) and static (rectifying- inverter, inverter-rectifying and various-frequency) converters examined in this article successfully meet basic criterion that is submitted to a promising Fully- Electrified-Aircraft electrical equipment. The suggested circuit design for the main power-supply channels and converters seems to be suitable for A/M scalable systems of versatile modular architecture with high mass-energy, reliability and operation-economical effectiveness. It should be noted that such a circuit design is protected by Russian Federation priority. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Le D. T., Averin S. V. Switching algorithms optimization for vector pulse-width modulation inverters . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 155-164. Implementation of vector pulse width modulation (VPWM) for of aircraft electric motor drives systems converters becomes one of topical trends. VPWM nowadays found application in many branches of industry and manufacturing to provide the quality of various electric motor drive systems control. Depending on motor connection to the inverter method several options of developing the power stage of the inverter are possible. The paper presents the structures most frequently used in practice. VPWM realization with three-phase bridge is most expedient. To control voltages across motor windings with microprocessor unit it is necessary to connect control action with switching sequence of power switches by analytic expression. It is necessary herewith to bear in mind that power semiconductor devices switching does not happen instantaneously. To obtain optimal analytic expression we used the technique based on Karnaugh-Veitch maps. The paper presents Karnaugh maps and command word (CW) generation for a three-phase bridge corresponding to the specified switching algorithm. It shows Karnaugh map permitted transitions. To obtain necessary command word allowing through currents elimination we suggest implementation of additional vectors. The states of power switches corresponding to these vectors are also presented. The paper presets such vector generating sequences, where the through currents do not occur, as well as the states preventing motor discontinuous currents. Analysis of suggested algorithms was carried out using MATLAB. Computer model of VPWM is presented. Breadboard testing fully confirmed the efficiency of suggested algorithms. The obtained analytical expressions for switching algorithms command word generation allowed eliminate through currents, reduce speed fluctuation amplitudes and induction motor torque ripples, as well as motor drive response speed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Schetinin V. E. Multi-cell inverters with even and odd power cells comparative analysis . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 165-174. The development of aviation technology gradually leads to increase of the on-board electrics and electronics number, including consumers of the first category, which are indispensable for the safe completion of the flight. In case of providing power from batteries, the issue of high-grade power delivery for vital consumers arises. As a candidate solution to the problem of inverter output power increasing we suggest to use multi-cell inverter comprising of several unit inverters, allowing distribute the total load. Besides, microcontroller implementation can result in better shape of the output voltage, increase of efficiency and weight and size characteristics reduction. The paper considers the technique of inverter output voltage generating according to an algorithm allowing approximate sinewave signal and provide equal loading of each unit inverter. Such an approximation allows increase the output voltage quality, reduce the size of each output filter, while the uniform load will allow unify the unit inverter and enhance the system flexibility in case of one of the components failure. For an odd number of inverter cells the amplitude of the approximated signal is identical to the reference sinewave and circumscribes the sinewave over its highest point. To provide a uniform load of all inverter cells, the author suggests divide each time interval of approximating voltage level into equal subintervals according to the number of inverter cells. With this, each voltage level is formed as a serial and parallel addition of the inverter cells voltages. This method of the inverter cells power switches commutation allows create scalable switched mode structures of multi cell inverters. Theoretically, the maximum number of inverter cells depends on the inverter cell power switch minimum switching time. The paper compares the simulation results obtained for inverters with even and odd number of power cells. The variant with odd number of cells dempstrated the best characteristics despite the lower number of unit cells. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shlyaptseva A. D., Petrov I. A., Ryakhovskii A. P., Moiseev V. S. Modifying additives complex effect on AK12 alloy structure and mechanical properties. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 175-181. The paper presents the study of the effect on AK12 alloy structure and mechanical properties while subjecting its melt to complex modifying treatment with carbon-bearing Freon12 gas and salt compounds. Based on earlier obtained results, we sel ected K2TiF6, BaCO3 salt compounds and carbon (graphite) as modifying compounds. KA12 alloy processing with the sel ected compounds was performed both without and with its melt blowing-down by the above mentioned gas. Mechanical tests results and microstructure analysis revealed that the Freon-12 blowing-down makes modifying impact on AK12 alloy. The highest mechanical properties, and refining of ?-solid solution dendrites and refining of silicon particles in an eutectic is observed at simultaneous treatment of an AK12 alloy by the modifying salts (BaCO3 + K2TiF6 + C) together with Freon. The strength of the alloy equals to176 MPa, and relative elongation equals to 9,40%. Besides, the Freon blowing-down increases the modifying effect for the majority of considered flux compounds. The alloy AK12 treatment with Freon and salts (BaCO3 + K2TiF6) is most perspective, compared to the alloy modified only by salts (BaCO3 + K2TiF6). The strength increased fr om 162 to 188 MPa, and elongation - from 7,70 to 9,01%. Based on thermograms obtained while the melt treatment, surface morphology data and elementary composition of AK12 alloy treated with test compounds, we made a conclusion on the presence of carbon-bearing disperse particles similar in composition to aluminum and titanium carbides in threated with salt compounds (BaCO3 + K2TiF6) and Freon alloy. Those formed carbides can be additional crystallization centers in the melt due to dimensional and structural resemblance with aluminum crystal lattice. Analysis of the results of the carried on research revealed the perspective of carbon-bearing materials, and Freon 12 in particular, implementation as aluminum-silicon alloy modifiers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Didyk P. I., Golikov E. A., Zhukov A. A. Film structure of aluminum-silicon alloy obtained by physical magnetron sputtering . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 182-185. Film structure of aluminum-silicon alloy (99% Al and 1% Si) obtained by physical magnetron sputtering was studied by electron microscopy and profilometry. The values of average aluminum-silicon alloy films with varying sputtering power, sputtering time and metal coating thickness were studied and obtained. With equal aluminum-silicon alloy films thickness, the sputtering time decrease results in alloy grains average size and quantity reduction. With power increase and sputtering time approximately twofold decrease the average grain size and number of grains per square millimeter decrease proportionally. The obtained grains size depends weakly on sputtering power and stays within the range of 290-330 nm with ± 7% precision. The average film grains size of aluminum-silicon alloy increases non-linearly approximately 25 times (from 20 nm to 500 nm) with film thickness of aluminum-silicon alloy increase from 0.2 mcm to 1.2 mcm due to sputtering time increase, which probably can be explained by substrate temperature rising due to of aluminum-silicon alloy condensation. The substrate temperature rise results in grain size increase. The grain size and their quantity are practically independent from sputtering power, but they depend on time of continuous residing in plasma burning zone and plates cooling efficiency. In vacuum, the plates surface has no time for cooling in the process of deposition, which leads to excessive ions mobility of sputtered material, grains formation and growth. The more time the plates reside in plasma burning zone, the higher the intensity of grains growth. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Skripko L. E., Yurkina E. S. Russian and International aerospace industry enterprises quality management systems specifics . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 186-191. Aerospace industry suppliers quality management systems (QMS) certification procedures differ substantially from each other at national and international levels. Depending on what objectives the organization requesting the audit pursue, it should decide on the type of the standard, against which to implement the QMS. It may be QMS the general standard ISO 9001, the industry standard AS 9100 or the military standard GOST RV 0015-002). It should decide also on passing conformity with QMS standards requirements certification, engaging either national or international certification body. The goal of this paper consists in considering the certification specifics at national and international levels and reveal their main advantages and disadvantages by comparative analysis, as well as work out recommendations on upgrading the certification effectiveness level at the national level. The results of analysis revealed that the certification procedures for compliance with the AS 9100 international standard are the most strictly regulated and controlled by the accreditation bodies, regulatory bodies and aerospace industry suppliers themselves. Such a level of control of certification procedures is possible due to a number of distinctive features of audits conducting for compliance with AS 9100industry standard. Firstly, while certification conducting in the aerospace industry the ICOP (Industry Controlled Other Party) scheme functions. ICOP is a conception, which assigns еthe right to control the suppliers to the representatives of the aerospace industry, certification bodies and accreditation bodies. Secondly, the results of audits, as well as information about all the participants of certification procedures (accreditation bodies, certification bodies, auditors and certified suppliers) is displayed in the on-line database OASIS (Online Aerospace Supplier Information System), which ensures the transparency of certification procedures. In addition, the aerospace industry is characterized by the high degree of involvement of all concerned parties in formulating the requirements for conducting audits. The listed specifics of aerospace industry supplies certification at the international level guarantee a high level of confidence in the issued international AS 9100 certificates. Accordingly, for the goals of company's development at the international level and for obtaining more customers, it makes sense for the aerospace industry suppliers to undergo certification for compliance with AS 9100 at the international certification bodies. Those conclusions could be used by Russians aerospace suppliers while selecting the certification body. The second application area of the paper results is the Russian certification and accreditation system. As for Russian certification bodies, to improve the efficiency of their operations, as well as increase the level of confidence in the issued national certificates, an important step consists in study and use of the experience of the international system of QMS certification in the aerospace industry, as well as the Russian accreditation body (Rosaccreditation) joining the joining the International accreditation forum and the ICOP scheme. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Novikov S. V. Business strategy goals and problems realization indices system development. Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 192-199. The article is devoted to Russian corporations' competitive recovery realization in modern economic conditions. The authors study the issues of national hi-tech enterprises competitiveness by, among other things, these enterprises strategic plan indicators improvement. Complex analysis of modern administrative methods allowing optimize the production program of the enterprises based on improvement of the researches organizational technological level (OTL), design and production was carried out. The article defines organizational and methodological principles of optimal organization and production management system, and presents the developed model of optimal production and planning system model based on organizing and methodological principles and methods aimed at successful realization of goals and tasks of the enterprise. The authors formulated one of such methods, namely, a method of indicators optimization in conjunction with developing production OTL as follows: the conventionsl production OTL is determined by progressive norms and regulations, and optimal OTL is suggested for a specified program. The obtained optimal OTL indicators form the basis of developing and realization of production OTL modernization from the existing level to optimal. The authors present the method of strategic plan indicators optimization using adaptive economic and mathematical models with more details. They stressed economic efficiency of the introduced innovations while determining the enterprises' optimum production program including the suggested special standard coefficients, which adapt an abstract EMM to specific conditions of corporation development. It provides facilities for system and integrated approach while developing enterprise management strategy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Protsenko E. V., . . Aviation mechanical engineering scientific production enterprise innovative projects risks assessment method . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 200-207. The authors have developed a scientific and production enterprise innovative projects risks assessment method. Difficulties of identifying risks of various types and a problem of their assessment are associated with the fact that Scientific Production Enterprises realize simultaneously a set of projects being at different stages of life cycle. In this regard, the authors offer the use the “risk portfolio”, which means the overall risk of innovative projects portfolio, which size does not exceed the appetite risk level accepted by the company. By “risk portfolio” assessment, the authors mean the process of identification and quantitative assessment of innovation projects portfolio realized simultaneously by the enterprise. The quantitative assessment procedure of risks stipulating the risk portfolio level is based on determining the value composing it by questionnaire survey of experts. The electronic questionnaire in MS Excel allowing obtain an integrated assessment of a risk event after entering certain data introduced by experts has been developed to assess the risks of innovative projects realized by the scientific and production enterprise. Thus, after risks levels assessment of the innovative projects realized simultaneously by the enterprise the possibility to determine the size of the risk portfolio becomes possible. Modeling of innovative projects realized by Scientific Production Enterprise risk portfolio state can be realized by creating a cognitive map. The method offered by the authors will allow control the size risk portfolio within the risk appetite level accepted by the enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chaika N. K. Industrial park organization and economic forming mechanism based on production enterprise . Aerospace MAI Journal, 2016, vol. 23, no 3, pp. 208-217. The paper presents the analysis of the existing approaches to industrial parks forming. The analysis revealed that much attention is payed attention to this problem. The issues concerning industrial parks terminology and classification, their establishing criteria, structural elements, business legal structure and sources of financing are also tackled. However, mechanisms of an industrial park establishing and functioning are not considered. The industrial parks based on industrial enterprises forming assessment system, unity on terminology and industrial parks classification as well as a single mechanism of their forming, functioning and regulation on a statutable level are also missed. It should be noted that, in some cases, industrial parks present an effective tool for solving economic and social problems, as well as contributing to the development of Russias innovative potential. Theoretical and methodological basics of industrial parks based industrial enterprises forming are developed. The paper substantiates the possibility and actuality of industrial parks creation based on industrial enterprises. On the one hand, the need to solve socio-economic problems of regions, on the other hand, the presence of starting conditions for the industrial parks creation (production areas, equipment, financial capital). The paper suggests criteria allowing identify industrial enterprises as the territories with potential for industrial parks establishing potential. The purpose of industrial parks creation based on industrial enterprises consists in improving the competitiveness of products through the introduction of science-intensive technologies; diversification of production; development of knowledge-based industries; development of innovative entrepreneurship and infrastructure. The paper suggests the industrial park organizational and functional structure, including research and development block (research establishment, laboratories, and experimental design bureau), production unit (enterprise, manufacturing a product), infrastructure block (firms, engaged in financial, marketing, legal and other services). Industrial park fiscal system is suggested. The paper reveals the most important criteria for industrial park functioning:
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Panasyuchenko P. S., Artamonov B. L. Selection of tilting steering gear parameters and estimation of its implementation effectiveness for a single rotor rotary-wing structure. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 7-13. Modern advanced helicopter should have not only vertical take off and landing and hover capabilities but also high cruise speed and long range. Compound helicopter can reach high speed with the same engine power by optimal use of the main rotor, additional fixed wing and propulsion system. Producing lift wing reduces main rotor thrust required and prevents the retreating blade stall. Propulsion system thrust provides the fuselage optimum angle of attack when it does not produce negative lift and has minimum drag. One of the most effective ways to produce thrust at high speeds is tilting the tail rotor. In this case all the power from the main turboshaft engines will be used at hover and also at high speeds, shared between main and tail rotors. As an example the authors take single rotor helicopter with two VK-2500 turboshaft engines, additional 15 m2 wing, propulsion prop with 3.2 m diameter and 11900 kg take off weight. To reach maximum cruise speed (385 km/h) 2500 hp should go to the tail propeller which is 70% of all power produced. However, different blade washout is required at cruise speed flight (the longest flight mode) and hover for best performance of such a propeller. For this purpose at Mil Moscow Helicopter Plant flight simulator the most effective washout was determined. Because of additional wing and tail rotor tilting system compound helicopter is 400 kg heavier then a conversional one. But even with lower service ceiling (greater weight, negative wing lift at hover and more anti-torque rotor power required) it has 15% higher cruise speed and range which can be shown both at high and low flight altitudes with up to 13000 kg takeoff weight. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Akimov E. N., Balyk V. M. Outer set polynomial modeling in constructing an optimal type aircraft system. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 14-23. The article considers a method of statistical synthesis of a distribution function of targets between various types of aircraft. It presents statistical samples, describing an optimal type aircraft system in large, as well as samples describing the function of target distribution. The process of building of design and functional bindings that model aircraft systems at large starts from forming a statistical sample, which input data represents the characteristics of a goal set, while elementary functions of targets distribution by aircraft types are taken as intermediate characteristics. We accept the values of criterion of optimality as output data. This work assumes as criterion of optimality the cost of aircraft system. Intermediate characteristics have special meaningfulness when modeling aircraft systems. According to the principle of mathematical model self-organization, at successive complexity increase of a model (in the course of the transition from a linear model to a square one and further to higher degree models) all external criteria pass through their minimum. It gives the possibility to obtain a model of optimal complexity, unique for each criterion. In self-organizing theory of complex systems models all basic algorithms for building models of optimal complexity are based on grouped account of arguments. Combinatorial algorithms appear effective for problem order no more than the specified sample size. For problems of higher complexity, such as designing systems for an optimal type aircraft, the multi-row algorithms become more effective. The perspective of multi-row algorithms should be noted, since, in principle, they are the prototypes of genetic algorithms, which allow solving simulation problems of with dimension of several thousand variables. However, whichever the algorithm is, it does not allow going beyond the framework of the specified class of basic functions. These algorithms increase only the complexity of the model within a specified basis. With statistical synthesis employed in the paper the modeling algorithms are built in the way that provides the possibility in principle to obtain the models involving various basic functions. This corresponds to the basic statistical synthesis concept, according to which the output data of the initial statistical sample is modified in a certain manner in the process of building of a mathematical model. This adjustment is carried out according to the conditions and requirements that the formed model should meet. Thus, at each stage of the mathematical model building we form the statistical sample inherent to it, and the inherent optimal system of basic functions corresponds to each sample. The article presents the analytical models of the targets distribution function, which represent an approximation of statistics reported in terms of trigonometric polynomials. The article considers the operation of statistical sampling reduction, which reduces the initial n — dimensional sample to n one-dimensional samples, and operation of inversion allowing obtaining the inverse sampling required for the formation of inverse functions. Based on these operations, build one-dimensional functional relationships between characteristic functions and outer target set characteristics presented in the form of trigonometric polynomials. The paper presents a simple, but at the same time effective way to meet the statistical functional limitations. This method is based on statistical sampling regularizing. It consists in replacing or eliminating fragments of statistical sampling, which do not agree with the specified limitations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Trifonova T. I., Shelyukhin Y. F., Shukhovtsov D. V. A model of non-stationary aerodynamic longitudinal characteristics. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 24-41. Aircraft dynamics modeling at high angles of attack requires adequate reproduction of all forces and moments acting on the aircraft under these conditions. Until recently, accounting for the ambiguity (non — stationarity) of lifting force and pitch moment coefficients cy and mz dependencies causes difficulties due to the lack of simple enough mathematical models of this phenomenon. The problem is aggravated by the need to calculate the aircraft dynamics in real time, which is mandatory for the bench research and crew training simulators. The paper considers the problem of developing mathematical model of such kind based on the data obtained by the results of the tests of the of twin-engine passenger plane of the traditional scheme model with the of OVP-102B installation, which reproduces the aircraft model angle of attack harmonic oscillations at different setting angles and frequencies. Based on the analysis of dynamic dependencies cy(α,ά) and mz(α,ά) obtained as test results we proposed a rather simple model for the coefficients cy and mz calculation as a function of the current angle of attack α(t). The model is based on the static dependencies of lifting force and pitch moment coefficients cy and mz conversion by the first order differential equation (aperiodic link) with time constant T depending on the angle of attack and its rate of change. The paper presents the technique of the input parameters and time constant forming based on known cy(α) , mz(α) and α(t) dependencies. The comparison of non-stationary characteristics computed by the model with the results of wind tunnel and flight tests confirmed the suitability of the developed model for computation and experimental research of aircraft dynamics at high angles of attack. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Masherov P. E. A cylindrical langmuir probe primary probe holder size effect on the results of local plasma diagnostics. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 42-49. The purpose of this work was to study the primary probe holder of a cylindrical Langmuir probe relative size effect on the results of local plasma diagnostics. The primary probe holder radius, that should be far less than the electrons free path average length was the main subject of consideration in the presented paper, because it is the primary probe holder that is able to decrease the concentration of electrons and change other parameters of radiated plasma in the spots of its probing. It significantly affects the quality of local plasma diagnostics. Three types of cylindrical probes made of tungsten thread of 0.15 mm in diameter were used. All three probes were provided with probe holders of the same diameter of 1.6 mm. The idea of the work consisted in obtaining measurements from the probes of various lengths under equal impact of the primary probe holder, which increased surface, allocated near the probed area contributes to recombination of charged plasma particles on its surface, and, thus reduces the level of ionization equilibrium in the radiated plasma. The cylindrical probe of a certain length averages the parameters of plasma in its scope. The invariable local distortion of plasma parameters near the probe holder affects differently the measured results for probes of various lengths. The work employs such probe lengths range that allows point out their bound, outside which the disturbances of the considered type become less than the total error of probe measurements. The paper describes the experiment with HF induction (HFI) discharge in Xenon and probe measurements carried out using probe station Plasma Sensors VGPS-12. A number of technical features of VGPS-12 allows increase the accuracy of plasma diagnostics results, narrowing down, for example, electron density measuring error field to the value of about 10%. These features include: implementation of Dryuvesteyn method that does not require prior guesses on the shape of the electron energy distribution function in contrast to the other probe techniques; suppression of the most part of errors by protecting reference electrode with developed surface; probe surface cleaning by ion bombardment and HF current heating. The work is concluded by the analysis of the obtained results, allowing formulate recommendations on selection of the main sizes cylindrical Langmuir probes to ensure the acceptable plasma diagnostics accuracy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moshkov P. A., Samokhin V. F. Experimental determination of piston engine share in the light propeller aircraft power plant total noise. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 50-61. The article presents the results of experimental determination of the of the piston engine share in the total power plants noise of the light propeller aircrafts An-2 and Yak-18T, MAI-223M and MAI-890U, performed under static conditions at the local aerodrome. The article provides a brief overview of the mechanisms of noise generation by the aircraft piston engines. The power plant emission band consists of harmonic and broadband components. Its sources are piston engines and propellers. Based on measurements at several points of the acoustic far-field narrowband spectra we separated harmonic components emitted by the propeller from those emitted by the engine. Separation of the high-frequency component of the engine broadband noise against the background of the propeller whirligig noise appeared to beimpossible. The possible source of the dominant radiation is the turbulent wake behind the rotating blades. The important share of piston engine harmonic emission of the total emission power of engine-propeller power plant is experimentally revealed, and under lower engine operating modes An-2 and Yak-18T (at Mach circumferential propeller velocities less than 0.7) in particular. The paper presents the factors affecting the piston engine share in the total propeller power plant noise. It also studied the effect of nosing engine on acoustic power level of the engine fundamental tone. It was found that the nosing of the engine could be considered as one of the waysof the afield noise reduction of ultralight aircraft MAI-890U. We obtained acoustic emission patternsof piston engines typical for light aircraft. Aircraft ASh-62IR and ROTAX-912ULSengines emissioncharacteristic maximums correspond to the azimuth angles of 0° in the forward hemisphere and of 135-150° in the rear hemisphere. M-14P engine emissionis relatively even over the space in the direction angles of 60-120°. Typical minimum levels of engine noise observed on the axis of the crankshaft, i.e. in the direction of 0° in the forward hemisphere and 180° in the rear hemisphere. One can use these emission patterns in the future for the noise prediction models of aircraft piston engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozlov A. A., Avrashkov V. N., Borovik I. N., Chudina Y. S., Kozlov O. A. Two-stage reusable space transportation system implementing liquid rocket engine and scramjet demonstrator. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 62-70. The paper tackles the issue of effective space system design. The experience of developed countries proves that such transportation system may include hypersonic loop. The Faoulty of Flying Vehicles Engines in Moscow Aviation Institute (National Research University) has developed the conception of the reusable space transportation system (STS) based on liquid rocket engine (LRE) and scramjet. The idea of using available stock of propulsion systems development forms the basis of the concept. Space Transportation System consists of two stages: the booster (first) stage and the orbital (second) stage. We plan to include RD-161P engine into the booster stage of the propulsion system. This engine is in progress at «Scientific-production association „Energomash named after academician V.P. Glushko“». Orbiter has a dual-loop propulsion installation consisting of a scramjet and a low-thrust thrust (500 N) rocket engine. These engines are developed at the Faoulty of Flying Vehicles Engines in Moscow Aviation Institute. To select the fuel type for the use in space transportation system, we compared several fuel compositions that meet the environmental requirements, high efficiency and assimilation. As a result, we chose the fuel: high-concentrated hydrogen peroxide and kerosene. The successful flight of a returnable STS requires taking into account the effect of flight conditions on the flying vehicle control. We propose to create a demonstrator and simulate all phases of flight STS with the aircraft of significantly smaller size. The following demonstrator flight scheme is assumed: after orbital stage separation, the first stage continues moving along its ballistic trajectory. Parachute is ejected, and then at the height of 3km helicopter grabs the first stage. The helicopter delivers dry assembly to the launch pad for reuse. We conducted ballistic calculations and preliminary design studies. As a result, we obtained weight characteristics and the model of a demonstrator. Payload weight is about 4% of the take-off weight of a demonstrator. With an increase of take-off weight of an aircraft up to actual STS weight levels (100-200 tons), the aircraft placing into LEO payload efficiency reaches 10% of the take-off weight. Using well-known and calculated demonstrator performance we developed demonstrator flight control system: ground control post hardware and on-board equipment. Phases and modes of flight demonstrator are similar to space station Buran project. It facilitates the implementation of the existing stock and flight control algorithms. The developed concept of a two-stage reusable space transportation system is designed with two types of propulsion — LRE and scramjet, operating with high-concentrated hydrogen peroxide and kerosene. We suggest to use the demonstrator to make more precise the impact of flight conditions on the efficiency of STS. Calculations кreveal that the efficiency of the aircraft payload placing into LEO reaches 10% of the take-off weight. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kalabuhov D. S. The study of ultralow power turbine with diagonal impeller work process features. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 71-79. The subject of the research is ultralow power turbine with axial nozzle set and diagonal impeller. The purpose of this work consists in improving the ultralow power turbine efficiency. The paper describes the features of the work process in ultralow power turbines with diagonal impeller based on the equations of momentum and energy. It also studies the effect of the impeller degree of bias and the ways of its meridian profiling on energy characteristics of nozzle set, the impeller and the turbine in whole, using numerical methods for viscous flow 3D modeling with ANSYS CFX. The results of the analysis are based on theoretical concepts of work process within the diagonal turbine impeller. The author derived equations of flow radial balance and flow energy within the impeller of diagonal type. It was found that implementation of diagonal impeller rather than axial provides an effective solution. It allows increase of power efficiency of the turbine. The turbine efficiency at rating conditions with loading implementation of diagonal impeller rather than axial parameter YT = 0,23, the rate of pressure reduction and calculated degree of reaction was increased by 9% due to diagonal impeller implementation with constant blade height in meridional section with impeller midline to turbine axis tilting angle . It was found also that impeller meridional profiling technique does not affect turbine effectiveness within the range of rational values . Small size turbines with shaft power Nt = = 0.01...10 kW and working fluid flow are meant for various accessory drives and auxiliary power plants, energy systems for space and surface transport, as well as processing tools.
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Soe T. . The necessity of developing aircraft maintenance and repair centers at myanmar airports. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 80-91. The goal of this work consists in substantiation of creating the central maintenance and repair (M&R) system at Myanmar airports, and development the criterion of its breakeven. The author carried out retrospective analysis of aerodrome network and air transport in Myanmar. The conclusion is drawn about the necessity of creating technical maintenance and repair system, one of the main elements of integrated logistics support. The criterion, which must be followed while forming of such kind of system, was developed, and this criterion is system operation breakeven. This means that the M&R system total operating revenue over a calculation period has to be greater than M&R system total expenditure over the same period. Since the volume of proceeds is determined by the market of such type of services, minimization of M&R system costs should be the basis of this problem solution. This solution requires determine the compromise between aircraft designers (consideration of M&R system personality for each aircraft) and interests of air companies, reaching after reducing aircraft M&R costs upon observance of flight safety requirements. Creation of such network requires scientific substantiation given in this paper. The obtained results can be used while taking investment decisions related to the development of Myanmar economy. The deficiency of aircraft M&R may entail drastic consequences, such as poor condition of aircrafts and, consequently, increase in aviation accidents. It will lead not only to deterioration of air companies position domestically, but also will seriously affect the budget, for tourism is the most important revenue item of the country. The paper considers the problem of aircraft maintenance and repair at Myanmar airports. The paper reveals the deficiency of such system in Myanmar. For such system formation, we need to elaborate requirements to M&R system and Myanmar airports with allowance for airlines interests, form general criterion and constraint system. On their basis we should develop the maintenance and repair system for Myanmar airports. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dunaev D. V. Analysis of expert evaluation methods use for planning ground development test of rocket technology products. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 92-99. This article presens the analysis of the of expert evaluation methods (EEM) implementation for planning ground development test (GDT) of rocket technology products. To do this, all necessary conditions for experts’ qualitative evaluation were considered and recommended EEM were sel ected. Multilevel EEM implementation is marked herewith, where the upper layer determines the order of experts’ polling — discussion (brainstorming, synectics, commission of experts and court), or questionnaire (Delphi method). While selection of low-level EEM is determined by the specific practical problem. To simplify GDT optimal planning all products are sorted according to qualification status (corresponds to qualification method). Then selection of types, test categories to develop the required operation characteristics and their sequence for each assembly unit is carried out (corresponds to scenario methods or PATTERN, forecast graph). The problem of selection and assortment of the necessary types, categories of tests is just the most complex one during GDT plan elaboration. It is suggested to solve this problem by the selection of the appropriate product-analog (corresponds to Churchman-Akof method) with allowance for its performances, as well as a product (assembly unit) requiring optimization. This will reduce the duration and cost of GDT planning phase. Further development of the assembly unit optimization plan for those operation characteristics that differ fr om the characteristics of the prototype, types and test categories are determined by any of the recommended EEM (mostly by scenario methods and brainstorming). Thus, as a result of the multi-level application of EEM, it is possible to elaborate an experimental development optimal plan in terms of minimization of material and time resources. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhigastova O. K., Pochukayev V. N. Automated flight planning software complex for unmanned spacecraft database. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 100-109. The article considers the database (DB) designed for software complex of automated flight planning for unmanned spacecrafts (SC) [1]. This DB is meant for storing data for flight planning complex, as well as exchanging data with other complexes of the Mission Control Center (MCC) and the external organizations involved in the spacecraft control process. The method under consideration for developing a database involves the use of a relational database architecture. A relational database presents all data in rows and columns of the table. Areas of tables allocation are called table space. Apart fr om these tables they also contain indexes, notations, constraints, rules, default settings, triggers, stored procedures, user-defined functions and data types. The above listed elements are the objects of the database that are used for its building. The unmanned spacecraft automated flight planning database is structurally divided into four table spaces. The first contains information about the space-time state of the spacecraft. The second contains data necessary to solve the problems of automated planning and its automated checking procedure. The third is the archive of data exchange between software complex of automated flight planning and MCC complexes. The fourth stores output data, transport files and receipt tickets generated in the course of the exchange with the MCC complexes and external organizations involved in spacecraft control process. All DB tables are arranged in accordance with hierarchical structure. We use two types of tables: table header and their subordinates. The header table contains general information and characteristics of the object, such as the composition of spacecraft groups or ground stations that provide control, while subordinate ones contain specific data structure of the spacecraft equipment, lists of commands, the types of tools used during the sessions. The database has been designed to integrate the individual elements of unmanned spacecraft automated flight planning into a unified complex. It presents the link between the complex software modules and provides their interaction with each other and with MCC complexes. The outcome of the work led to the development of unmanned spacecraft automated flight planning software complex Database. The proposed structure of the database allowed arrange data, set forth its hierarchy, provide storage and access to data and support data integrity. The cre ate d database allowed simplify the separate software modules interrelation procedure of the automated flight planning complex and MCC complexes, providing multistream data access as well as simplifying the search for necessary information. The developed Database was implemented at MCC as a part of an automated spacecraft flight planning software complex. It saw used in the course of flight control of a spacecraft of scientific and socio-economic purpose. The automated flight planning for unmanned spacecraft software complex Database can be used for automatic spacecraft of scientific and socio-economic purpose control.
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Brusov V. S., Nefedov L. V., Lishchinskii M. A. Unmanned solar energy powered air vehicle climbing along quasi-cyclic trajectory optimization. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 110-117. The capabilities of modern photovoltaic transducers form the performances of the solar energy powered UAV. Solar energy ensures the flight at low speeds. High-altitude flight allows avoid the impact of clouds and provides a large view scope. High-altitude flight is carried out within the high kinematic viscosity environment that significantly reduces thereby the Reynolds number. An important feature of the aircraft consuming solar energy to maintain its flight consists in specific range of flight heights and speeds, characterized by low Reynolds number. These flight conditions are associated with non-linear dependence of aerodynamic characteristics from the incidence angle, which complicates the use of traditional methods to optimize the flight path. The flying vehicles of such kind require the technique allowing optimize the flight path with allowance for these features. The proposed climbing trajectory optimization method partitions the optimization process into two stages. The first stage consists in flight parameters region characterization, guaranteed to exceed the specified value, while the second stage is the stage of trajectory providing minimum power consumption search. The search for the trajectory allowing minimum power consumption is carried out by the direct numerical method, without characteristics linearization. Such an approach allows optimize climbing trajectory of the aircraft having non-linear aerodynamic characteristics, peculiar to the flight at low Reynolds numbers. We obtained climbing trajectories with allowance for Reynolds number and without it. The results show that energy consumption while climbing with allowance for non-linear aerodynamic characteristics are about 4% higher than the results obtained without the regard of those non-linarites. This may cause the energy shortage for flight support and lead to multi-day mission failure. Optimization of high- altitude solar energy powered UAV flight path requires regard of Reynolds number effect of aerodynamic characteristics. The flight paths computation of the UFVs of such kind is worthwhile to carry out by numerical methods, stable to aircraft aerodynamic characteristics non-linarites. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Arutyunov A. G., Krivichenko Y. O., Medvedev A. S., Orlov V. S. On-board equipment complex architecture for prospective transport aircraft. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 118-124. The article presents the structure of the on-board radio-electronic equipment that meets modern international requirements of CNS/ATM conception and is based on integrated modular avionics (IMA) principles. Implementation of IMA conception allows provide high reliability, enhanced functionality and compliance with modern requirements to on-board radio-electronic equipment. Architecture of the on-board equipment includes computer complex, description of information for flight deck information management field and software applications. The computational part of the complex project includes the contents and datasheet of computing blocks, as well as the contents and designation of mezzanine modules, which perform special functions and determine functionality of the crates. The flight deck information management field arrangement corresponds to modern allocation schemes of information consoles and allows provide their effectiveness and ergonomics. This field consists of five 15’’ multifunction displays, two head-up displays and two Electronic Flight Bag (EFB) data tablets for the pilot and co-pilot. The article presents the description of and information frames distribution over multifunction displays. The article outlines the on-board equipment functions executed by software applications while IMA conception realization. Functional software realizes all modern communication, navigation and surveillance functions. The software applications are executed by the computation complex crates. The article suggests the applications distribution over the crates according to their functionality. The proposed project of on-board equipment complex differs from the existing ones in large state integration of IMA systems, realizing functions of automated control systems, flight-control-navigation and radio-communication equipment. The project of on-board equipment complex for prospective transport airplane presents scalable multifunction fault-tolerant complex corresponding to the requirements for transport category aircraft, and meeting the prospective ICAO requirements to air traffic navigation and control. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybaulin A. G., Sidorenko A. S. Tensity and endurance of a structure with discrete weld bonding under stationary random vibrations. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 125-137. Discrete weld bonding are zones of increased stress concentration, formed due to heating non-uniformity during welding process and significant difference in mechanical characteristics of a metal in weld junctions from those of a parent material. Under repeated loading action the occurrence of fatigue fractures evolved between weld materials at the contour of a weld point is most probable. The fatigue endurance of the structures with weld bonding is determined, for the most part, by the stressed state dynamic characteristics at local zones of weld points. To obtain the proper durability estimation of such kind of structures one should define stressed state dynamic characteristics with allowance for its essential spatial non-uniformity and local changes in material properties. The paper presents the technique and results of a structure with spot-welded joints subjected to random vibration probabilistic characteristics computation using finite elements simulation. Simulation of the dynamic stress state was executed for the structure under random kinematic loading conditions with the specified power spectral density function of acceleration. To substantiate the correctness of the simulation of spot-welded joints the authors studied by computation the samples of spot-welded joints, tested for static strength under tensile and shearing, and plotted vibrating stress spectral characteristics for various points of the structure. Zones and levels of maximum stresses were determined. Features of dynamic stress state in welded joints were revealed. Estimations of specific damageability and mean longevity of welded joints under various theories of accumulation of fatigue damages were obtained. The attribute of the study consists in detailed modelling of dynamic stress state at welded joint considering significant changes of the properties of the parent material over spot weld cross section. The properties of the material at spot weld local zones are determined based on micro-hardness yield stress empirical dependences. The developed technique and numerical simulation results can be applied to assess the vibration strength of thin-walled structures with discrete welded connections. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Klykov A. V., Tomilin M. M. Aircraft steering gear system current amplifier transients simulation. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 175-184. During the last three decades, the design effort is being concentrated on realization of more all-electric aircraft concept. We can assign to this class the planes incorporating, either power hydraulic or pneumatic actuators for energy-intensive installations control, or electric motor drives controlling various functional objects, such as steering rudders. Nowadays the research effort is focused on two types of drives design — electromechanical and electric hydrostatic drives. The electromagnetic interference (EMI) generated herewith by electric drive motors in the form of electromagnetic fields may affect the operation of aircraft on-board equipment which, in some cases, causes failures. Furthermore, electric drive modules represent receptors of external radiated and conducted interference, which may distort control signals, formed by microcontroller and, hence, conducted EMI in motor windings in the form of phase currents transients. Thus, it is necessary to know the levels of motor phase currents, occurring during various transients, to provide normal operation of the dive and evaluate electromagnetic environment within the aircraft interior. The goal of the paper consists in the analysis of the phase currents transients occurring in the steering drive system (SDS) motor, based on the results obtained by computer simulation in OrCad 9.2. The paper presents waveforms of phase currents in motor windings, obtained with OrCAD simulation. The phase currents levels in actuating motor windings may be about 1.5 times greater than their rated values while operating mode variation. The above said currents and the EMI they induced in the form of electromagnetic fields affect the electromagnetic environment within the interior volume and are of serious hazard to electronic equipment of either SDS, or to aircraft on-board equipment. The presented paper is a part of research on calculation and simulation of electromagnetic interference caused by the transients in current amplifier of an aircraft SDS motor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okunev V. S. Improving accuracy of non-rigid component parts surfaces positional relationship while manufacturing. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 138-148. The article touches upon the methods allowing increase the precision of non-rigid cylindrical parts processing. When producing non-rigid component parts, the work pieces processed surfaces deformations subjected to the forces are scaled to machining tolerance values, which leads to the occurrence of processing errors related to it. The article tackles the issues of finding deformations of non-rigid work pieces walls during mechanical processing, depending on cutting operating conditions, to optimize the manufacturing process and enhance accuracy. We suggest calculate the work pieces surfaces deformation under the impact of the cutting force by using the finite-element method and the elasticity theory provisions. As a check on the possibility of using the finite-element method to calculate deformations while processing non-rigid cylindrical work pieces, it is necessary to have an analytical checking solution. We examined such solution based in the general thin-walled shells design theory. The paper consists of three main sections. The first section presents a detailed calculation of deformation due to cutting force impact while non-rigid cylindrical work pieces processing according to the general thin-walled shells design theory by the example of a thin-walled cylinder. The necessary reference data to determine cutting operating conditions are included. The second section deals with the calculations based on the finite-element method. It gives appropriate recommendations to improve thin-walled parts computational accuracy and demonstrates the graphic solution results obtained with Abaqus and Ansys programs. This section considers the selection of finite elements for thin-walled machine parts calculation as well. The calculation results are compared with the results obtained by the exact analytical solution. This section considers the possibilities of calculations based on contact method of cutting force estimation and other cutting parameters with Abaqus and Ansys program module. A conclusion on poor computation accuracy and impossibility of its implementation for the problem under consideration solving was made. The paper gives recommendation, allowing correction of technological process parameters at the stage of process design, with due regard for non-rigid work pieces processing errors due to their surfaces deformation caused by cutting force. It considers the possibilities of the presented computations automation based on the finite elements method for various kinds of geometry and design features of component parts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kaz'min A. I. Phasor technique for measuring physical parameters and defect detection of radar absorbent and composite materials. Measuring and computing system for its implementation. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 149-159. Experimental studies of properties of radio absorbent materials and coatings to solve the problem of aviation complexes radar visibility reduction hold a unique position. Foreign and domestic proves that without development of laboratory and testing site base achieving sound results on this issue is impossible. One of the main problems of experimental research within the framework of the problem of the radar signature reduction is the study of physical parameters of radio absorbent materials. The purpose of the research is to develop a new measuring technique of radio absorbent and composite materials complex permittivity. The method consists in measuring signals in orthogonal channels of a receiving device (special horn antenna) as the ratio of voltage and phase difference. For a specified voltage ratio and phase difference, we introduce such notion as “phasor”. Phasor modulus and its phase angle characterize real and imaginary parts of a material complex permittivity. This technique demonstrates improved accuracy due to account for the imaginary part of permittivity. A special horn antenna allows increasing the penetrating power of electromagnetic waves and reduce the “effective” radius of the field interaction zone with the material. The antenna consists of a dual H-waveguide, two orthogonally arranged two receiving and two transmitting dipoles. The paper presents measuring and computing system implementing the abovementioned method. The system consists of measuring system, mathematical support and software. The results of experimental research of different dielectric materials, including samples of radio absorbent and composite materials are presented. Experimental studies confirm the high accuracy and sensitivity of the developed technique. The “phasor” technique can be effectively used for studying physical parameters of existing and prospective models of radio-absorbent and composite materials for aviation complexes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhidik Y. S., Troyan P. E., Voronyuk E. E. The study of electrochromic materials for viewports with dynamic shadowing implementation. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 160-166. The purpose of this work is to study and compare the characteristics of electrochromic devices based on inorganic materials, such as WO3 и Fe4(Fe(CN)6)3 for using in passenger cabin viewports with dynamic shadowing. The study of various electrochromic devices structural variants based on these materials revealed that the structure configuration based on Fe4(Fe(CN)6)3 allowed obtain the most effective result. Moreover, device characteristics such as the transition time to colored state and the transmittance in the bleached state deteriorate with increasing thickness of the electrochromic layer due to deceleration Fe3+ ions reduction to Fe2+ ions. The optimal variant of electrochromic device was the device with the electrochromic coating thickness of 400 nm, which transmittance in the visible range varies from 68 to 21% when the potential difference of 1.5 V was applied for 3 seconds. With the electrolyte concentration increase, the coloring / bleaching time was found to be increased due to reduced velocity of the ions, caused by the increase of the Coulomb interaction between the ions of the electrolyte. The best coloring / bleaching time was obtained by using 1 M KCl solution. Ease of operation, low power consumption, and high-speed dimming should be noted when such devices are implemented for passenger cabin portholes dynamic shadowing. The major shortcoming of inorganic electrochromic devices today is the limited number of coloring / bleaching cycles. Due to this, the inorganic electrochromic devices are almost completely ousted from the market by electrochromic devices based on liquid crystals and polymers (Pdlc). A disadvantage of the devices based on liquid crystals (Pdlc) is that they have only two states: fully transparent and fully shadowed, which eliminates the continuous adjustment of the device. Thus, electrochromic devices based on inorganic materials have a great potential for development and competition in the market of electrochromic devices, one of which is passenger cabin portholes with dynamic shadowing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Prokof'ev M. V., Zhuravlev S. Y. The study of nano-dispersed graphite particles size and shape effect on electrical conductance and thermal resistance of carbonaceous coating. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 167-174. This work is devoted to the study of activated graphite structural characteristics and coatings on mineral fibers. It considers metallized coatings obtained by fabric vacuum spraying-up as an alternative to carbon coatings, and examines their properties, advantages and disadvantages. By the time variation of the preliminary grinding, temperature and oxidation time the optimal conditions of chemical activation of graphite powders and particles with high particle diameter to thickness ratio were determined. Physical characteristics and thermal resistance of coatings on basalt and glass fibers were determined using various techniques of colloid graphite particles aqueous and alcohol dispersions current-conducting material coatings. Basalt fibers over glass ones substantial advantages, such as adhesion reduction due to acid nature of graphite activation, were revealed herewith. By X-ray structure analysis and laser diffraction technique, we determined the original graphite pastes characteristics and found that graphite particles sizes and anisotropy parameters had decisive impact on the possibility of thermal shockproof radar absorbent materials formation. The X-ray structure analysis data allows make the main conclusion confirming the well-known fact that in the process of graphite powder high temperature activation the structural compression of a material and partial burnout of amorphous component occurs. According to coatings microstructure study by scanning electronic microscopy we can conclude that the films are formed by carbon particles agglomeration (flaking plates). The paper considers various types of chemically activated graphite, which have vital structural and morphological differences. They can be formalized by the relationship of a flat particle diameter to its thickness. The possibility of obtaining thermal shockproof coating by impaction of particles with high anisotropy, i. e. planar size to thickness ratio was revealed. The volumetric radar absorbent carbon materials of a composite fiber texture studied in the paper, which are either thermal shockproof or stable to high power electromagnetic emission, can be implemented for protection and electromagnetic compatibility provision of airspace electronic equipment. Radar absorbent carbon materials are stable under conditions of vacuum and radioactive impacts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bibikov S. В., Maltsev A. A., Koshelev B. V., Zudov K. A., Kudrov M. A. Promising energy accumulators - supercapacitors: operation principle and implementation for aerospace engineering. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 185-194. The purpose of the paper is to disclose the potentialities for improvements of supercapacitors, or so called ionistors, characteristics — one of the most promising types of energy storage devices along with expansion of their implementation area in aerospace engineering. Based on the analysis of the theoretical and experimental research results published by the developers in this area, as well as original studies, the authors present several ways of improvement of supercapacitor characteristics, first of all, their charge capacity and accumulated energy. It is proposed in particular to optimize the structure and the material of the electrode. For electrodes based on nanodispersed layered graphite structures the authors show the necessity and possibility of the availability of nanoporous electrode surface for electrolyte ions consideration. Another approach for increasing capacitance is a rational choice of an electrolyte. Different variants of aqueous and non-aqueous electrolytes, as well as solid electrolyte are analyzed in the paper. Advantages and drawbacks of various types of electrolytes are shown. To increase the energy accumulated by ionistors as well as extend the voltage range it is proposed to use non-aqueous electrolytes and create «nonsymmetrical» ionistors with redox process involved. Experimental testing of identical supercapacitor cells with different electrolyte solutions and their mixtures showed that the mixture of acetonitrile and ethylene-carbonate provided the best set of supercapacitor parameters (specific capacitance, self-discharge resistance and series resistance). The authors carried out additional testing of supercapacitor cells of various constructions with standard domestic electrodes and electrolytes to evaluate the rate of degradation process. Supercapacitors with multilayer axial structure demonstrated the highest parameter stability. Comparative analysis of superacapacitors characteristics produced by Russian and foreign manufacturers was carried out. Possible areas of supercapacitor implementation in aerospace engineering were studied with allowance for the peculiarities of their characteristics (high specific power and relatively small discharge time). Supercapacitors can be effectively used for various short-term power applications, drives, etc. in combination with other power sources. We suppose that developing power sources for unmanned aerial vehicles can be the most efficient area of implementation of superconductors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tihonov A. I., Silant'eva E. A. Key aspects of defense industry complex enterprises innovative development. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 195-199. The purpose of this work is to define the role of organizational and resource support for innovative development of defense industry complex (DIC) enterprises, and rocket engine industry in particular. To achieve the purpose the authors analyzed the DIC contribution to innovative development of the country, identified the main areas of DIC current and strategic development, and revealed the key aspects of leading enterprises innovation development. Currently the Russian Federation faces dual challenge, namely, launching innovative development mechanisms and raise a level of national security in military, economic, technological and other spheres. A solution of the above-mentioned problem is possible through intensification of development of defense industry complex, which concentrated considerable innovative potential. Implementation of this potential can activate innovative processes in the economy in large. In our opinion the main trends of DIC current and strategic development, are as follows: — firstly, to determine the most efficient trends of innovative development of high-tech industrial production and further search for the reserves and factors stimulating DIC innovative development and national economy as a whole; — secondly, to improve resource support, i. e. the system of coordination of legal, organizational, technical, financial and economic, scientific, technological and human resources at all levels of governmental and business activities. Resource support should be based on its consideration as a system, i. e. a group of elements (financial, labor, material, manufacturing resources etc.) organized in such a way that they are able to interact in block to achieve certain goals. The paper also analyzed the activity and the main documents regulating innovation activities at one of the leading rocket engine industry enterprises — NPO “Energomash named by Academician V.P. Glushko”. The analysis revealed that within the framework of unit power rocket liquid propellant jet engines for primary and second stages world market sector “Energomash” products has no business rivals. In this respect, the main goal of the innovative enterprise development means improving the competitiveness and economic efficiency of “Energomash” activities, guaranteeing the status of the enterprise, as one of the sectorial leader in the world market. This goal can be achieved by proper resource supporting of Innovative Development Program. “Energomash” personnel potential development is defined as a key factor of innovative development of the enterprise. The authors herewith analyzed the current personnel structure and revealed the tendencies of personnel support of the enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Semina L. V., Nikolenko T. Y. Innovative activities organization specifics on the example of the aviation company. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 200-207. Under conditions of innovative economy development scientific-and-technological advance, information technologies, wide spread occurrence and implementation of innovations become the main factors of social and economic development. Innovative orientation is an integral characteristic of modern economy. Factors affecting innovative activities are miscellaneous, but cooperation of enterprises with different companies, research organization, corporations and development institutions should be noted. Highly professional team and a new product are of great importance. Innovative activities of an enterprise should be considered in two ways: on the one hand, it is the result, presented in the form of new products or technologies; on the other hand, it means introduction of products, principles and approaches replacing the preceding ones at the enterprise. It leads to lower production costs, considerably improves consumer properties and quality of the product, and allows meet the growing needs of buyers in the market. The effectiveness of aviation industry enterprises activities does not consist in savings on the scope and the search for inexpensive resources, but in timely responding to the changes in the external environment. Only the enterprises that are able to adapt their internal environment to external changes without detriment to their activities can hold their competitive position in the domestic and world markets. The article discusses the issue of maintaining competitiveness through adaptation measures to changes in external environment. The efficiency of the processes during such changes at the enterprise depends on presence of its potentialities, which are determined by production, financial, investment, marketing, personnel, information, resource and scientific and technical potentials. We define the specific features of innovative activities implementation for enterprises of aviation industry. This article presents the example of organization of conditions for for linear friction welding innovative technologies implementation at the enterprise PJSC “Ufa engine industrial Association”. The paper considers the system of innovative development of an enterprise, as well as possible improvements and the impact of external and internal factors in the process of implementing innovative technologies. The main conclusions consist in the following: under conditions of the external environment dynamism, developing enterprises must constantly perform internal restructuring to adapt to it, to remain competitive during the strategic period. With that, the project review at various options, and considering all risks is necessary. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leonov A. G., Dovgodush S. I., Petrovskii V. S. On a system approach to space equipment design and implementation organization in projects of international cooperation. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 208-216. Realization of the system approach to cooperation of a parent enterprise of space equipment developers to the rational solution of multidimensional applied problems of the organization and carrying out international cooperation in space activities from positions of development, production and operation of space equipment is considered. The attention is drawn to the feature of the international space cooperation associated with the need of creation of conditions for its carrying out in all spheres of the state activity. Not only scientific, technical and economic, but also political, defense and social spheres are involved. For support of rational decisions adoption in such a complicated and multilevel process of options formation, their productivity forecasting and selection of rational decisions, one needs to invoke scientific methods of the system analysis. At the same time, the problem of non-systematized use of numerous system methods that negatively affect the adequacy of decisions by the target is revealed. Based on experience of the parent scientific and production enterprise engaged if creation of complex system developments and its participation in MTC, we suggest the model of display of the studied subject in spheres of the state activity. The model encompasses the following: legal basics of the international cooperation, questions of a partner in the international cooperation selection, creation of criteria of efficiency of cooperation taking into account efficiency and safety, the organizational and administrative principles of the development realization at the level of parent enterprise of the project joint participants cooperation. The model of competitive price formation with allowance for target efficiency and advantages of production of cooperation compared to analogs relating to the tasks and other interests of the importer state is offered. The presented material is based on the experience of concrete realization of the stated system approach of JSC NGO of Mechanical Engineering Military Industrial Complex, parent enterprise of cooperation, in the course of organization and handling of work in the field of military and technical cooperation at creation of rocketry, as well as the international cooperation in space area at creation of systems with radar supervision KA. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Novikov S. V. Structural transformations problems of modern corporations and enterprises. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 217-227. The authors of the paper under consideration study the issues of domestic high-tech enterprises competitive stability ensuring, and through consideration of their structural reorganization in particular. Complex analysis of problems of large corporations, such as bulging executive personnel, decision making procedure foot-dragging, decline in efficiency of associations and their response to the market requests was carried out. As a result, the response to the market requests decline limits the growth potential. Under economic conditions of Russia, it leads to market sectors loss. Besides, under conditions of Russian developing market and a large quantity of imported products in the market, the enterprises of bulky structure would appear uncompetitive in the absence of qualitative restructuring. The paper enlights the problems of Russian corporations and enterprises of micro-level management at the present stage of economic development, particularly, modern organizational structures of management (OSM) correspondence to the requirements of the new stage of economic development and states their improvement guidelines. It examines OSM relationships and existing market; analyzes the organizational and economic mechanism of corporate relationships with subsidiary enterprises, affiliates and organization departments, and offers recommendations for its improvement. The paper suggests an engineering model for improving the goals and policies on various levels of management in conjunction with their target trend. The authors solved low-level problems concerning ensuring management of higher levels goals and policy by implementing the concept of «matrix-diagonal management structure». They suggest use it when developing OSM for scientific production associations (corporations), where production departments are vertical elements, while horizontal elements are executive personnel of systems production and scientific and technological support. A number of functions herewith, where the functions of subdivisionы and executives intermingle, are performed by diagonal elements. Thus, the paper considers vital issues of an enterprise operation organization, their problems, wiсh hinder rate of economic growth at present, and keep on sticking for the most part to command-and-control methods of management, rather than economic. It leads to technical and economic slowdown. This paper has scientific and practical value for radio industry enterprises aircraft engineering trend. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kaloshina M. N., Chemerisova A. V. The concept of estimation of labor potential effect on sustainable development of the aerospace industry enterprise. Aerospace MAI Journal, 2016, vol. 23, no 2, pp. 228-235. The paper presents the concept of estimation of labor potential effect on sustainable development of aerospace industry enterprise that includes three basic phases: Phase 1: Airspace industry enterprise labor potential structure analysis. Phase 2: Analysis and selection of aerospace industry enterprise activities that depend on specifics of aerospace enterprises and labor potential characteristics. Phase 3: Evaluation of the enterprise cost with allowance for labor potential effect on its sustainable development. Phase 1 starts with selection of sustainable development indicators of the enterprise, analysis of the enterprise specifics, methods and approaches to estimating the enterprise’s labor potential and factors affecting it. At the first phase the optimum system of criteria for the particular enterprise according to the selected groups, as well as integrated estimated figures are formed. At the second phase of the concept we reveal and select such performance indicators of the enterprise, which depend directly in a greater degree on labor potential and in a lesser degree on indirect and background factors. The authors selected two indicators: “product cost” and “enterprise cost”. At the third phase the total cost of an enterprise is estimated within the framework of three approaches (extravagant, comparative and profitable) with allowance for sustainable development basic factor — labor potential. As a result of structural transformations in the industry by the example of Scientific-Production Association “Saturn”, structural changes policy was formed for each of selected trends based on changes of labor potential quantitative and qualitative indicators: staff personnel, fixed-capital assets, raw material stock and taxes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharov I. V., Trubnikov A. A., Reshetnikov D. A. Program-methodic system for the impact of guided aircraft missile of «air-to-air» class technical state on its guidance accuracy . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 9-18. Reference [1] presents scientific and methodological basics for technical condition (TC) assessment of a guided aircraft air-to-air missile (GAAAM) guidance-system (GS). For this purpose new concepts of functional hardware capabilities and military potential of the missile were introduced, including the aggregate quality indicators, determinant of which is the missile terminal miss. This article describes the tool and methodology to study and quantify the influence of GAAAM TC on the accuracy of its guidance, which can be used to implement the methodology described in Reference [1]. As a research tool the program-methodical system (PMS) was developed. Fundamentally, this system realizes complex mathematical models simulating targeting an aerial target (TAT). With that, on the assumption of the volume and the depth of problems at hand, synthesis of the PMS and methodology for the impact assessment of the GAAAM TC on the accuracy of its targeting, involves the solution of a given problem in restricted sense and in a wide one. The synthesis of this problem in a restricted sense is regarded as the accessible development tools (analytical tools) to study the required process or a specific object in a small area of varied parameters. In this form a similar PMS and the methodology were developed in [2]. Further it was tested in the thesis and several research papers. In a wide sense, synthesis of the estimation method involves solving of a set of interrelated problems within the framework of the multifactor experiment (MFE) with the large dimensionality of initial data for objects research and processes investigated. It includes a wide range of initial simulation conditions and the simultaneous action of several different factors affecting the results of the MFE. New modules were introduced in the developed PMS, including a module for the initial conditions setting for mathematical simulation of the guidance process based on approximate analytical dependencies. In addition, the additional cross-feedback connections were introduced and also a set of competing models were considered. The outcome of the experiment caused by a number of other factors independent from each. Among them, we can highlight the following factors: types of used guided aircraft missiles (GAM); current technical condition of a used one, the type of a target and its flight performance (FP); the type and nature of enemy air target counter-effort to attacking missile; the GAM carrier type and its performance; the nature of air vehicle combat and the engagement nature with the target; the specific initial conditions of the GAM start-up onto the target. In this regard, in PMS we applied five classes of modules to generate the initial MFE data, implemented by databases technologies: modules, determining technical condition of subsystems of GAMs; the modules that define the type of the target; the modules that define the GAM carrier type; the modules that form the initial conditions of combat use, the modules forming the end of the MFE simulation. The PMS is based on a complex of mathematical models for GAM aiming at a target process, including a model of a target movement, the model of a GAM as an object of control (OC), as well as a set of models of the GAM guidance system as OC. The specified models form a guidance loop, closed through the equations of the relative motion of the missile and a target (RMMT). Complex mathematical models of the GAM aiming process at the targets is realized in the programming environment Borland C++. Based on simulation results obtained with PMS for fixed conditions of combat use of GAM we obtained GAM and target motion trajectories; time depending functions of the change of the phase coordinates of the process of missiles homing at the target; 3D-functions of the quality indicator dependence from the two varied control parameter. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gusev V. G. Optimization of the wing unloading of a medium-range passenger aircraft . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 19-25. The features of a wing design of the modern medium-range passenger aircraft are considered. The main design deficiency of the classical single-fuselage scheme of the aircraft influencing the mass of a wing is the centrally located fuselage. The significant bending moment evolving thus in the wing root section is defining in weight calculations of its design. The configuration version of the twin-fuselage passenger airplane with a passenger capacity, identical with the single-fuselage airplane prototype, is offered. One of features of such configuration of the aircraft is presence of two instead of one fuselages with the pressurized cabins isolated from each other allowing single-level placement of passengers in salon at four chairs in the same row in each fuselage. This circumstance in addition to a flight safety and creation of more comfortable conditions for passengers allows to considerably increase unloading of a wing and reduce the bending moment in root section and the mass of its design. The power plant with three engines located on the wing of the plane creates additional benefits in comparison with the two-engine power plant at a possible engine failure. The four-leg fuselage undercarriage with two nose and two main legs also promotes increase of flights safety level in case of landing with a non-extended landing gear. The method of approximate calculation of a wing mass construction on the area of the bending moments diagram is offered. It is accepted, that the distributed mass loading of the wing design is function of the cross section area of wing bulkhead frame and normal stress is equal to the allowable stress. On the basis of the developed method the comparative estimate of a wing mass for the airplane-prototype and the twin-fuselage airplane scheme is made. Results of calculations confirmed efficiency of the wing unloading by fuselages removed from each other. The wing mass of the twin-fuselage plane appeared much less than a wing mass of the classical single-fuselage plane. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nebelov E. V., Pototskii M. V., Rodionov A. V., Gorskii A. N. Mechanism of damage propagation to the propeller blades of composite materials with exposed damaging elements . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 26-31. The article discusses the importance of the problem of reducing the life cycle of the propeller (propfans) because of foreign objects and elements of the weapons hits during combat operations connected with protected propeller blades (propfans) from exposure to particulate matter. Classification of combat damaged items of military equipment caused by the impact of a weapon of the enemy and related factors is considered. The paper describes the mechanism of formation and further damages evolution of propeller blades (propfan) made of composite material with the defeat of the elements of weapons. The results of multiple damage simulated with the help of software CAE ANSYS / LS-DYNA are shown. These results clearly show that there is a change of the physical and mechanical properties of the material associated with the formation of bulk or surface hardening, which leads to the appearance of residual stresses, which is confirmed by experimental data. Also, there are the results of multiple injuries received in experimental studies of impact resistance with blade AV-112 propeller propulsion system of military-transport aircraft IL-112, which shows that the striking element is overcoming obstacles in the form of layers of fiberglass, increases the deformation zone that appears in a large area of the opposing barrier damage as size holes, and on the thickness of the material bundle and exfoliation area tape on the exit side. The article shows the dependence of the area of separation against thickness of the bundle composite propeller blade resulting from an experiment and an example of the phase diagram characterizing the behavior fragments of the projectile in the form of a cube when struck by the blade in the composite spar at various angles of approach. The result is determined by the collision of impact velocity and the angle of the meeting. In the article the authors point out the adequacy of the emergence and development of damage to the propeller blades (propfans) made from composite material with the defeat of the elements of weapons, confirmed by the results of calculations and experimental studies conducted in VUNTS Force VVA named after Professor N.E. Zhukovsky and Yu.A. Gagarin in the department Design of Aircraft Engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kamenskii S. S., Martirosov D. S., Kolomentsev A. I. Similarity theory methods application for lpre steady-flow working procedures analysis. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 32-37. This work aims at searching similarity of RD170 engines family steady-flow operating procedures. We shall use generalizing functions describing interrelations of operating procedures parameters and valid for RD171M, RD180 and RD1971 for the formal description of the found similarity. This work offers the reduction procedure of tests data to dimensionless form and defines the type and characteristics of the desired generalizing functions, i.e. dimensionless parameters dependencies on thrust level, which are common for all engines under consideration. According to similarity theory, the propinquity of the equations describing behavior of dimensionless characteristics of the compared objects points to physical similarity of the processes described by these equations. Thus, obtaining the generalizing dependences reflects physical similarity of steady-flow operating procedures in structurally successive engines of RD170 family. Based on the generalizing functions derived from the analysis of the results of fire tests by similarity theory methods, we developed an algorithm of parameters determination of multimode LPREs of RD170 family, allowing calculate their values in wide range of thrust variations according to known rated values of slow parameters (SP). The obtained results show that generalizing functions can find application for SP calculation in an infant state of LPRE of RD170 family design, when mathematical model is not correct enough, and the first experimental materials can form the basis for adequately predictive estimate. The paper shows the possibility of using the results of presented work as references of normal functioning for solving the problems of function tests. The presented results of proposed method for firing test real time analysis within the space of which a throttle failure occured, confirmed the presence of such kind of failure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kalinin D. V., Kalinin Y. V. Two-stage transmission scheme design for perspective helicopter. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 38-46. Conventional commercial and military helicopters have flight speed limit of about 300-350 km/h. High-speed rotary wing aircrafts of the next generation require the increase of horizontal speed up to 450-500 km/h. Aerodynamic limitations, hindering flight speed increase of perspective high-speed helicopters, can be eliminated by reduction of the main rotor rotation frequency, while a helicopter builds up its high speed. This can be provided by implementation of regulated transmission with variable transmission ratio. The existing helicopter transmissions have constant transmission ratio. Thus, the development of regulated transmissions of anew type requires carrying out of exploratory study. The paper presents the results of the design of a new type of helicopter transmission with variable transmission ratio for perspective high-speed helicopters. It allows vary rotation frequency of the main rotor irrespective of engine and anti-torque, or pusher rotors rpm. The paper considers also the possibility of implementation and basic advantages and disadvantages of alternative types of regulated transmissions, such as, mechanical transmissions with stepped and stepless transmission ratio variation, as well as electromechanical versions of high-speed helicopters transmissions. It is shown that from the determining criterion point of view, i. e. minimum weigh and maximum efficiency of the transmission, the most effective and rational drive for a high-speed helicopter is a mechanical dual-mode transmission with stepped transmission ratio variation. The paper presents the description of a developed perspective stepless transmission scheme for a helicopter. The evaluation of dynamic forces acting during transmission transient modes with transmission ratio variation was carried out. Optimal scheme of the dual-mode mechanical transmission for perspective helicopters was developed. The important advantage of the developed scheme is the condition of safe operation, which consists in the fact that the coupling failure will not cause the braking of the force loop and loss of power at the main rotors. These design features provide high reliability of transmission operation and high functional characteristics with minimum mass increase in original structure of the helicopter main-rotor gearbox. This transmission mechanism is optimal solution for main rotors rotation frequency variation of perspective high-speed helicopters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zubko A. I. Perspective vibroacoustics diagnostic complex for aircraft gas-turbine engines bearing assemblies. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 47-55. The article tackles the questions concerning peculiarities of vibroacoustic diagnostics of bearing assemblies for gas-turbine engine rotors technical condition. Possible reasons of bearing assemblies damaging and corresponding failure symptoms of individual defects, as well as procedures of their application are analysed. The following options are possible in partucular:
The last item is preferable due to minimum financial and working hour costs. For implementation of such methods manual turning of the rotor and a specialist fixing data or carrying out rotor CS are required. In the course of diagnostics of operating gas-turbine engine aimed at researching possibilities of the technical microphone installed on the engine case a number of the methods connected with a high-frequency component of a signal spectrum of effective sound pressure was revealed. The studies consisted in searching of periodic and nearly periodic vibration processes resulting from bearing assemblies defect mounted on the engine and bearings tests bench. High frequency periodic processes occur very often either separately from nearly periodic, or together with them. They appear at identical excitation of a vibration signal with each turn. These are frequency modulation of vibration signals from damaged bearing parts, as a rule, with rotor frequency. Physical model of the process can be easily represented on the example of slider bearing operation. In the presence of negative factors, affecting the bearing clearance reduction, and occurring due to bearing capacity decrease or oil-film wedge punching, a mutual interference of wrinkles always presenting on sliding contacting surfaces takes place. It causes the excitation of oscillations of separate parts with frequencies equal to the product of number of interactions per one shaft rotation and rotor rotation frequency and natural frequencies of interacting parts. The vibroacoustic diagnostics complex «FIANITE 3000» was developed to realize the data obtained during the studies. It consists of a technical microphone (piezoelectric) with the restricted directional diagram, the DP-03 device, installed in inspection ports to inspect entrance edge of high-pressure turbine blades as well as electronic analysis and indication module FIANITE 3000. After DP-03 installation into inspection port and activation of electronic analysis and indication module the measuring process will go on automatically. The developed system of vibroacoustic diagnostics is autonomous and protected from the main interference generated by subassembly of gas-turbine engine. The total evaluation of the system revealed its very effective noise immunity and serviceability for single and periodic checkouts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolodyazhnyi D. Y., Nagornyi V. S. Experimental study of the electric field impact on the combustion products of a kerosene-air mixture speed. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 56-67. The intensive studies are carried out on developing high-speed transportation vehicles, providing high level of environmental security, as well as higher energy efficiency of aircraft engines by means of fuel spraying and kerosene-air mixture combustion enhancement in aircraft engines. To improve the fuel spraying and fuel-air mixture combustion quality we suggest to use properly formed electrical fields in nozzle fuel supply contours. We considered for the first time the AC electric field of varying frequency impact on chemical composition of combustion products at the combustion-chamber outlet when using aviation kerosene TC-1 as a fuel. Moreover, we presented for the first time the experimental results of the of the AC electric field of varying frequency impact on the velocity of combustion products of air-fuel mixture. Combustion products velocity measurement at the outlet of combustion chamber test model was carried out using the test bench at SGAU (Samara state Aviation Institute). Electric field impact on the of combustion products of air-fuel mixture (kerosene) experimental research technique The experimental velocity measurement of combustion products of an air-fuel mixture technique was developed at Samara State Aviation Institute and taken as a basis of the research on AC electric field impact on combustion products of kerosene-air mixtures velocities. Employing measurement data, we calculated the gas superficial velocity and mass flow using well-known equations for gas-dynamic functions. The result of the experiment allowed forming the file in Microsoft Access Data Base format with the possibility of export to Microsoft Excel. The results of velocity profiles laser-optic measurements using 3D-LDA LAD-056C equipment. The experimental studies were carried out at Samara State Aviation Institute with single-burner segment of the combustion chamber test model with serial double-contour nozzle of JSC “Klimov” for liquid fuel. The swirler with blades angle set at φ = 72°10’, transition liner with outer cone diameter of 133 mm, square shape adapter with 180 mm side and basic variant of the mixer zone holes with all holes open were used . TS-1 kerosene was used as a fuel. Low-pressure compressed air was fed at ≤ 0.75 MPa. Solid tracer particles of CH-4 type for laser measurements were used. When the AC electric field was applied along each diameter to the kerosene flow before its injection into the fuel nozzle the velocity changed to higher and lower values intermittently. Maximum relative decrease of kerosene-air mixture combustion products velocity at the outlet of combustion chamber herein was 2.45%, while maximum relative increase of kerosene-air mixture combustion products velocity at the outlet of combustion chamber in case of applying AC electric field to kerosene flow was 1.42%. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ezhov A. D. Numerical solution of a problem of rough surfaces interaction in power plants. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 68-79. The design of modern power plants contains a significant number of coupling structural components of various shapes and geometries, made of materials differing in mechanical and heat-transfer properties. Most important task while creating a reliable power plant consists in correct calculation of thermal contact resistance occurring due to non-ideal contact of mating parts, and, as consequence, retraction and extension of heat flow lines to contact spots, as well as higher temperature gradient within the contact zone. All these factors reduce heat-conducting ability of the contact and cause different thermal expansion of the adjoining parts, leading to relative shifts, deflection and warpage of the parts. The surface roughness is considered to be one of the key factors in solving thermal contact problems. Analysis of the literature on modeling and forecasting of contact thermal resistance shows that in practically all the works contain some analytical simplifications and assumptions concerning surface microrelief. In particular, irregularities were modeled as a variety of geometric shapes. The behavior of one pair of interacting irregularities was extrapolated to describe the behavior of a pair of interacting surfaces coated with irregularities. But if one takes into consideration the time when the suggestions of the CCC definition (60-70) were put forward, then we can say that the simulation of three-dimensional models was not carried out due to insufficient computer resources. Despite this, there have been many achievements in the field of metrology and methods of numerical analysis.The optical measurement of surface features at the micro and macro level and the surface condition data storing in a digital form became possible. The numerical and finite-element modeling of contact problems with complex geometry, boundary conditions and material properties setting appeared. Generally, to evaluate the temperature difference losses, the contact thermal resistance is introduced by different empirical formulas. But their diversity, incompletely given conditions of obtaining experimental data on which basis these relationships were obtained cast doubts on the correctness of the selection of a particular equation. While the differences in the absolute values of contact thermal resistance for the same conditions make it difficult to use them. On the assumption of the formed problem, analysis of contact pairs of different materials was performed, and comparison was made with the known calculation dependencies. Analysis of the known calculation dependencies to determine the CCC showed that the results obtained by rather accurate modeling of the ongoing process and analytical solutions differ, but they also have a number of matches. Nevertheless, the presented algorithm for calculating the CCC provides rather accurate values of temperature fields for almost all pairs of materials with minimal costs of the experiment. The use of this approach in engineering analysis allows reducing significantly the time of further testing and refinement of the product. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorelov Y. G., Strokach E. A. Conformities analysis of heat transfer coefficient calculation from the gas at high-pressure turbines entry nozzle blade edges . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 80-85. At the preliminary design stage of gas-turbine engines and high-temperature gas-turbine power plants one should use criterion dependencies to evaluate heat transfer coefficients from the gas at entry nozzle blade edges. Analysis of various criterion dependencies revealed that for the majority of correlations under consideration the degree of gas flow turbulence behind the combustion chamber was about (1 - 5)%, though for modern gas-turbine engine and high-temperature gas- turbine power plants Tu = (15-20)%. Information that behind the gathering main preceding the first stage nozzle set the degree of turbulence ε= 3 … 4% is not confirmed by the data obtained by Thole K. A. et al, Gandavarapu P., Ames F.E., Ames F. E., Nix A. C. at al, and in the area of maximum temperature field circumferential non-uniformity behind the combustion chamber. Thus, the paper by Thole K. A. et al shows that according to experimental results, verified by experiments and calculations with aircraft combustion cameras is gives 19%. To compare various design procedures and identify the margins of their implementation the presented paper carries out comparison of criterion dependencies for the averaged and maximum local heat exchange at the entry blade edge with the results of 3D conjugated numerical calculation using ANSYS CFX and 2D calculations of turboprop engine nozzle blade with entry blade increased diameter. The results of various techniques comparison revealed that H. Consigny and B. E. Richards averaged heat exchange criterion dependence should be used to evaluate the entry blade edge perimeter averaged heat exchange coefficients from gas. To evaluate maximum over entry blade edge perimeter heat exchange coefficients from gas, and in in the zone of combustion chamber maximum circumferential non- uniformity in particular (T*g = 2100 К and Tu ≈ 20%), maximum heat exchange criterion dependence should be used. This dependency was obtained by the results of heat exchange while straight cylinder flow-around study carried out by Ekkert E. R. and Drake. As far as it is necessary at the preliminary design stage of turboprop engine nozzle blades to evaluate, in the first place, their high-temperature strength for the applied material, this design stage requires the use of criterion dependence . Position of maximum heat transfer coefficients over perimeter of the entry edge and their outstretch along its bumpy surface depends on many factors: gas backstreaming angle, gas turbulence intensity (Tu) behind the combustion chamber, the value of maximum gas temperature field circumferential non-uniformity behind the combustion chamber, and others. Thus their location should be determined for each particular blade at the stage of 3D conjugated numerical calculations. The data, hereafter, on maximum local heat exchange coefficients on the entry edge external surface are verified experimentally. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Klimov V. G. Comparison of turbine blade wing of heat-resisting alloy geometry restoring techniques. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 86-97. Compressors and turbines of aviation gas turbine engines are the main components that determine the engine performances. Turbine blades are the most costly elements while their production. Rejection of an unfit turbine blade usually happens due to insignificant defects and consequently, their restoring is economically sound. This article considers the process of geometry restoring (height) of aviation turboprop engine NK-12MP turbine starters (TS) blade wing. A comparative analysis of four types of restoration has been carried out: argon-arc surfacing with filler wire ХН60ВТ; soldering with solder powder VPr24 in ceramic forms; laser surfacing with filler wire ХН60ВТ; laser surfacing in powder bath with VPr24 solder. The furnace soldering in ceramic forms technique consists in placing the blade in a specially prepared form repeating the ceramic blade profile with the necessary allowance for further machining, with further powder solder filling. Then the soldering process in a vacuum furnace begins. The technique of laser welding in a powder bath consists in surfacing of the blade wing placed in a bath filled with facing powder. The blade was placed in the powder fill so that its wing and the surface of the powder fill were at the same level. The laser beam worked on the tangent of the blade wing and the powder. Based on blade restoration techniques comparative analysis I concluded that the most effective technique in this case is pulse laser surfacing. Surfacing in powder bath herewith provides higher performance compared to laser surfacing with filler wire. Laser surfacing main differences from the classical techniques of turbine blades geometry restoring are revealed. The paper presents comparative analysis of the restored layers structure by electronic microscopy with elemental analysis of transverse sections of the samples. The degree of the effect of each technique on the blade basic material was revealed. It is found that the furnace soldering and laser surfacing techniques exert least effect on the strengthening phase γ’ of the cast alloy GC-6K. The elemental analysis revealed the presence of, presumably, the grid of complex intermetallic compounds, as well as tungsten and chromium carbides in the solder structure. Microhardness (Hv) of the recovered layers and various phases of powdered solder VPr24 was determined, and the CTLEM (coefficient of thermal linear expansion of material) involved in the restoration process was measured. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sokolov N. L., Orlov D. A. Design-ballistic studies of the problem of a spacecraft descent in Mars atmosphere . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 98-106. Spacecraft optimal control arrangement in exceptionally low-density Mars atmosphere, with allowance, in the first place, for the necessity to provide in the atmosphere the entry corridor of a required size,as well as effective deceleration of a spacecraft. Solution of the problem under discussion depends, in many ways, upon the proper selection of rational values of design and ballistic parameters of vehicles in descent mode and control methods in atmosphere. The present work studies design-ballistic problems of a spacecraft descent in Mars atmosphere. It evaluates the characteristic trajectory parameters under various flight conditions of a spacecraft and analyses alternative control methods of a spacecraft. The obtained materials would contribute in many ways to substantiation of layout and rational technologies of spacecraft control during its letdown on Mars surface. The article estimates physically realizable an entry corridor for a spacecraft with various aerodynamic quality values unchangeable in the course of the flight. It shows that with aerodynamic quality values decrease, the upper and lower boundaries of the entry corridor increase. The upper boundary of the atmosphere entry corridor of a spacecraft herewith is determined by overload maximum allowed value: the more the overload, the less the corridor upper boundary. One of the ways of the spacecraft atmosphere entry corridor expansion is an effective quality management. It allows almost double the entry corridor width compared to implementation of spacecraft of a ballistic type moving with constant aerodynamic quality values. An effective technique of final velocity extinguishing in atmosphere during the final leg of the flight of a spacecraft is introduction of soft landing system, which comes into action at the height of 5-9 km. The advantage factor of the final velocity decreasing is reduced front surface loading reduction. Thus, reduction of the value from 350 kg/m2 to 200 kg/m2 leads to decrease of the values to 60-80%. In this conjunction, it seems necessary to carry out the studies of the dual circuit control of roll position and incidence angle of a spacecraft, which may provide significant reduction of the final velocity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhurin S. V. Parachute-jet soft landing system with elastic linkage. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 107-114. The article is devoted to theoretical study of the soft parachute-jet landing process. It proposes to use a long elastic linkage to suspend a load to the parachute. Figura illustrates the operation of the parachute-jet landing system with elastic linkage. The engine thrust in the case of a hard suspension is 2.2 times greater than in the case of an elastic suspension.
The results of dimensions analysis for this problem reveal dimensionless groups, describing the process. A simplified mathematical model is built to describe the process of soft parachute-jet landing with an elastic linkage. As a result, of systematic numeric studies a rather simple interrelation between the dimensionless groups was found out. These obtained dependencies can be used for preliminary design. Implementation of the elastic linkage allows significant reduction (several times) of soft-landing engines thrust. In its turn, it enables reduction of the following negative factors of soft-landing engines operation: This enables you to reduce the following negative factors operation of the engines of soft landing:
Application of the elastic linkage makes it possible to meet more fully the requirement on standardization of the existing parachute-jet soft landing systems with the possibility of continuous (not discrete) adjustment of system parameters to the given mass of an airdropped object. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pisarenko V. N. Flight reliability . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 115-122. The paper presents and analyzes the conditions and of a characteristics of the flight on modern aircraft with a crew of two pilots. The analysis of the flight is made in terms of flight safety. Examples of real events in the air, which led to the disaster due to the fault of the pilots, are described. Today, Airbus of A320 family performs the main air transport service, so the aircraft A320 control system is considered as basic for this analysis. The aircraft with a crew of two pilots control model in the form of man-machine system is built by converting the control system A320. Using mathematical tools of linear algebra the automatic and manual control of the aircraft structuring was carried out. Manual control of the aircraft is performed using SIDE STICKs by the captain and a co-pilot. More precise requirements to aircraft automatic control negative feedback were developed. The problem of the plane commander, which steer consists in the necessity to fly the aircraft in case of aircraft systems failure or incorrect actions of a co-pilot, was described mathematically. The model of the aircraft automatic control feedback transfer coefficients matrix was built in LabVIEW. Numeric and analytical studies of aircraft piloting in the form of the process of flight control were carried out. The definition of flight reliability was represented as a function of aviation equipment failure-free operation and error-free performance of the crew. The equations for flight reliability calculation under automated control and during active control of both pilots are presented. The regularity of reliability reduction due to aircraft automatic flight control system failure or non-participation of a co-pilot in controlling an aircraft is determined. Reliability calculation equations for operation in such conditions are presented. Detailed recommendations for flight reliability ensuring during crew preparation to the flight and flight operation are given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Trinh V. T., Nguyen N. M. Airliner automatic landing optimal trajectory shaping based on anthropocentric principle . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 123-135. This paper considers and algorithm of optimal landing trajectory shaping. Realization of this trajectory in automatic mode will maximally simplify the problem of transition to aircraft manual control. Aircraft landing is considered to be the most laborious phase of the flight. The basis of the algorithm development consists in selection of automatically controlled trajectory as close as possible to the trajectories implemented by the pilot in the course of a manual landing, which will provide maximum convenience for the pilot in case of automatic landing failure. Thus, enhanced flight safety is provided. The principle of the methodology consists in creation of formal specification of pilots actions during manual landing in the form of several optimization problems based on pilots actions in the course of manual landing. Thus, we consider the pilot as an optimal regulator, which performance criteria are sel ected according to the analysis of experimental data obtained earlier. As far as we consider manual control mode, the algorithm of control actions development should be made consistent both with emerged situation characteristics and with current characteristics of the pilot as well as the aircraft. The paper analyses and formalizes flaring-out stage of the flight, which will provide landing safety. For this purpose, we realize on board the aircraft the flaring-out modeling algorithm with various options of throttle control and flaring-out altitude. Optimization herewith consists in selection of throttle control law and flaring- out altitude, wherein maximum regulator (a pilot, or ACS) error is tolerable. Control performance of a pilot is considered in the course of studying of quasi-linear model which parameters are determined by recurrent identification in the process of flight realization. We formalize glide-path capture in the form of the problem of optimal aircraft control, which criterion parameters are obtained fr om the experimental data analysis of successful variants of manual landing approaches. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhigastova O. K., Pochukayev V. N. Flight plan development language allowing automatic flight planning for automated spacecraft . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 136-146. The article considers the flight plan development language, used in software complex for automated spacecraft (SC) flight planning [1] to describe instruction structures [4] and prepare the initial flight plan data. Design/methodology/approach The language of the flight plan development is based on methods of structural, modular and object-oriented programming. [3] Like other high-level languages, the language of the flight plan development consists of characters, tokens (basic structure), expressions, operators and classes. The problem of developing a new language stems from the need to develop a tool allowing describe commands used to plan the flight control and actions performed according to them. The flight plan development language uses six types of data such as integer, character, logic, calendar date, time and n-tuple to store control commands parameters vector. All calculations made are control commands execution time operations. This language defines variables for command time values storage. Each variable consists of type and name. The type determines the properties of a variable, and the name points for which command it is necessary to make calculation. Calculation of values is performed using the operations, which determine what time operations should be performed. In addition to time operations, this language defines execution of conditional operations. Conditional operations are used to set the conditions for issuing control commands implemented during n a spacecraft communication with ground control station. To provide repetitive calculations the language uses the cycle statement. To describe more complex language constructions, used to compile a flight plan, «classes» were included. These Classes are used to describe the command structures. They represent a model carrying out an action executed by either SC, or a Ground Automated Control Complex. The elements that constitute such a structure can be both control commands and command structures themselves except the given one. The language of the flight plan development was created for a formalized description of the command structures and the initial data used to compile a flight plan in an automated way. It allows describe the flight plan elements and structures more clearly, hiding the details of their realization. Its helps to provide the input data preparation for an automated spacecraft flight planning software complex. Findings This work results in creation of the flight plan development language for an unmanned spacecraft automated flight planning software complex. It aid in the description of structures and preparation of the input data used for compiling the flight plan in an automated way. The developed language made it possible to formalize the description of the flight plan command structures, the initial data structure and simplify the way to describe them, while reducing the number of operators used in the description. The created flight plan development language was implemented at the Mission Control Center (MCC) software as part of a complex of automatic spacecraft mission planning and has been used to prepare the initial data for the flight control of space crafts of scientific and socio-economic purpose. Research limitations/implications The flight plan development language can be applied during preparation of the flight plan initial data to control an automatic spacecraft of scientific and socio-economic purpose. Originality/value
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Iordan Y. V. Oxygen content analysis on an atmospheric phase over descending trajectory of rockets' jettisonable parts. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 147-150. The paper considers the problem of space application rockets' launching technological environmental impact reduction, particularly in the field of reducing the area allocated for the regions of rockets jettisoned parts impact areas. Nose fairing (NF) shatters are selected as a subject of research. The goal of the study is further development of impact areas reduction based on NF burning in dense atmosphere. The paper sets out alternative techniques of NF shatters impact areas reduction, including representation of the suggested technique based on introducing thermite-igniting compound (TIC) to NF structure. As thermite-igniting mixtures, one can implement salts or metal oxides (KClO3, KClO4, CuO, etc.) mixed with one or several powder metals, such as magnesium powder, aluminum powder, titanium powder or their alloys. A binding substance, such as colloxylin is possible as well. The amount of mixture required to start the igniting process will depend on weight content of oxygen in the airflow, since combustion stability reaction just depends on its amount, and, hence, the required amount of heat emission as well. The paper presents oxygen weight evaluation on the descent trajectory by the example of NF for the rocket carrier “Soyuz-2.1.v”. As a result, the time interval within which the combustion process should be realized. Evaluation of the developed technique adequacy was carried out. The obtained results are the initial data for further development of NF burning in dense atmosphere. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolichev I. A. Application of dual numbers for solving the problems of interorbital flight optimization. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 151-162. Subject The subject of this article is to analyze two aspects of application of the dual numbers for solving optimization problems of the multi revolution interorbital flight of the spacecraft with electric propulsion system. Purpose The purpose of this article is to demonstrate the possibility of using dual numbers in solving complicated optimization problems of the interorbital flight. Methodology The paper analyzed two aspects of application of the dual numbers to calculate the required derivatives during the solving optimization problems of the interorbital flight of the spacecraft with electric propulsion system. The use of dual numbers allows to determine the values of the derivatives with relative accuracy equals to the precision of function computation. The first aspect corresponds to the use of dual numbers with a single dual part together with the continuation method for calculating the elements of the sensitivity matrix of the system of nonlinear equations corresponding to the boundary value problem of the Pontryagin maximum principle. The second aspect is the use of dual numbers with vector dual part to calculate the right-hand sides of the system of differential equations, which describes the optimal process. By virtue of the canonical formalism of the maximum principle it is necessary to calculate the optimal Hamiltonian in the dual representation. This approach is used for solving the optimization problem of the interorbital flight when the model of the spacecraft motion takes into account various disturbances. Results The results of two types optimization problems of the interorbital flight of the spacecraft with electric propulsion system between the initial elliptical orbit and geostationary orbit are presented in this paper. The first type of problem corresponds to the motion model of the spacecraft in the central gravitational field under the influence of the reactive acceleration. For the second type the model takes into account the effect of the Moon and Sun attraction, and disturbance caused by the Earths gravitational field noncentrality. The functional that corresponds to the minimum mass of required fuel quantity is considered for both problems. Solution of the first type was obtained by using the continuation method and approximation of elements of the sensitivity matrix using dual numbers with a single dual part. For the problem of the second type, dual numbers with vector dual part is often used when we determining the right- hand sides of differential equations of optimal motion of the spacecraft. The nonlinear boundary value problem in this case was solved by a hybrid Powell algorithm. Practical implications Overall, the methodological approach of the using dual numbers for automatic differentiation outlined in this paper can be used for solving any optimization problems, where model of the object motion is described in a complicated manner. Conclusions This paper shows, that the using of the device of the dual numbers for computing required derivatives can efficiently solve complicated optimization problems of the interorbital flight of the spacecraft with electric propulsion system.
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Vasil'ev M. A., Stepanov V. S. Wave gear with roller bodies kinematic error computer simulation . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 163-169. One of possible approaches to determine kinematic error is functioning modelling in MSC. Adams, which allows investigate static and dynamic characteristics of machinery and mechanisms. The following errors affect the kinematic error of harmonic gear drive with rolling bodies:
The article presents the results of wave gear with rolling bodies mathematical modeling in MSC.Adams at nominal deviation of sizes of certain parts of the gear. The kinematic error of the gear at a constant rotation frequency was determined, and its harmonic content was analyzed. Dependencies of kinematic error components on the values of the gear links sizes deviations, such as wave former disk diameter and rolling bodies diameter, is revealed. In accordance with the results of the studies, we can make the following conclusions:
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Nosov A. S. Justification techniques for the structure, configuration and parameters of a drivegear with roller drive of increased accuracy and operational reliability selection . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 170-176. At present, the requirements placed on power actuators include increase of load capacity, positioning accuracy, reliability, durability, efficiency, impact resistance, and a number of other parameters. The required speeds and accelerations of the output element of the drives are increasing as well. Drives should be easily mounted on the object, replaceable and adjustable. Their servicing should be simple, and their control should be reliable and easily programmable. For most products, especially of the space industry, it is necessary to reduce the weight of the drives and maintenance facilities. The environmental requirements placed on the drives are constantly toughening. The analysis of the requirements placed on the drives for special aggregates reveals that they should provide: · Fast response and playback accuracy of a desired motion law; · High precision of moving; · Synchronous operation of two or more drives; · Greater amount (range) of the output element speed control; · Higher soft ride of large mass products at low (micro) speeds; · Minimal and stable energy losses values. In addition to the abovementioned, a power actuator should have a simple technological design, low weight and size, and high operating reliability. Recently, the demand for the planetary roller-type actuators (PRTA) as the actuating mechanism (AM), especially for the military and aviation equipment, increased significantly in our country. A number of companies are trying to master serial production of PRTA, which requires to address the issues of PRTA analysis validation and design, production technology of the actuator parts and their assembly, as well as high-precision metrological control of PRTA parts critical dimensions, using the appropriate equipment. PRTA has a number of advantages: · High load capacity; · The possibility to provide light feed at high load; · High reliability; · Low sensitivity to temperature variations; · Ease of mantling and dismantling of the transmission; · Ability to work with high rotation speeds; · High efficiency; · Low metal consumption. Based on the conducted studies of mathematical models and well-known techniques [3, 4], a technique for a prospective PRTA AM structure and parameters justification was developed. To solve such problems, the experts of FSUE «CENKI» — «DB «Motor», MADI and N. E. Bauman MSTU proposed to use the planetary roller-type transmission as the actuating mechanism. Theoretical and experimental studies under the scientific supervision of Professor A.N. Sova and candidate of technical sciences A.V. Sizanov are conducted on the manufactured friction planetary roller-type transmission 48×12, and the control system on a specialized workbench for transmission running test is prepared. Research is conducted at the branch office of FSUE «Center for exploitation of space ground-based infrastructure», — «Design Bureau «Motor» using the CNC milling machine Hardinge Bridgeport GX1000. A measuring device is sel ected based on the desired accuracy of transmission. Digital measuring head Mahr Extramess 2000 with permissible error G = 0.6 μ m was used in the study. Conclusion Thus, implementation of scientific and methodological approach and the conducted research allow us:
· Take into account the longevity reserves of contact fatigue damage, in-service wear, and quality of the lubricating layer; · Determine the optimal value of the actuator mass to ensure a pre-set speed without overshoot; · Reduce deviation of the experimental results fr om theoretical results; · Develop scientific and methodological support of the results of the machine-aided design of the actuator with high dynamic performance, reliability and durability implemented with CAD/CAM/CAE system.
At present, planetary roller-type transmission is the most promising device that converts rotational motion into linear. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chigrinets E. G. Titanium-reinforced glass fiber plastic main rotor blade beam drilling process optimization . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 177-188. High-tension polymeric composite materials (HTPCM) are widely used in aviation industry due to their high strength-density ratio and modulus of rigidity; good shock-absorbing capacity; corrosion resistance and low thermal-expansion coefficient. HTPCM tooling, however, is associated with a number of difficulties. Its low thermal conductivity affects the heat balance: the main part of heat, about 90%, is concentrated in the cutting area and at the drill tool, whereas up to 70% of heat leaves the cutting area with chip scrap while tooling metals. This high temperature causes partial melting of polymeric matrix, tempering of tools and processed surface. Composites anisotropy of properties leads to differences in chip formation along and perpendicular to the reinforcing fibers and their high hardness causes increased wear of the drilling tool. Delaminations, caused by axial force and torque of the cutting process, are formed in the places of drilling tool entering and exit. The purpose of this work is to study the impact of the structural and geometric parameters of drilling tools on the quality of the processed holes, productivity, dynamics and thermal physics of the high strength polymeric composite material machining — titanium foil reinforced glass fiber plastics. Extra loaded polymeric composite constructions implement titanium foil reinforcing packs, allocated between the layers of reinforcing glass- or carbon ribbon.To provide required accuracy in size of apertures macro- and micro-geometry, elimination of tempering and delaminations of the material one has to use sharp-ground tools and carry out processing in stages. This work studied drilling process of fiber-glass laminate at various schemes of high-speed steel drill tools sharpening. The work presents the results of processing rates optimization for the studied tools geometries; dependence of unevenness tallness parameters; the character and value of delamination in the places of drilling tool entering and exit, depending on the tools type and processing rates, as well as qualitative image of chip formation. Using the developed computerized real-time measuring system for power characteristics of drilling process, we found blunting criterion and efficient life of the cutting tools under study. The pyrometric registration data on average temperature in cutting area allowed perform finite elements modeling of thermal processes occurring while multilayer plastic, reveal the sources and directions of the thermal flows, and, finally, develop recommendations for technology improvements of apertures processing in glass fiber beams of main and steering rotors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Budkina E. M., Kuznetsov E. B. Modeling of technological process for aircraft structural components manufacturing based on the best parametrization and boundary value problem for nonlinear differential-algebraic equations . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 189-196. Among mathematical models describing various processes associated with manufacturing engineering, aerospace technology and aviation, there are models representing a system of ordinary differential equations and a system of nonlinear algebraic or transcendental equations, i.e. a system of differential-algebraic equations (DAE). Such problems often arise in applied mathematics and mechanics. Some hydrodynamic processes described by the DAE systems contain a small parameter (viscosity). Problems of this type describe the phenomenon of creep. The process of creep of the material in the first approximation can be modeled by DAE systems discussed in this paper. The basic methods of solving boundary value problems for such systems are methods of collocation and shooting methods. With shooting method, a boundary value problem is reduced to some initial value problem. However, this method is applicable only in the case when the original problem is correct. We suggest to apply the best parameterization for regularization of this problem. The paper considers the system of nonlinear differential-algebraic equations. It is shown that the best parameterization of the boundary value problem for a singularly perturbed differential-algebraic equations significantly improves the computational algorithm of the shooting method. The numerical solution of the problem was obtained using the method of solution continuation with respect to parameter and the best parameterization. The boundary value problem is reduced to an initial value problem for differential-algebraic equations. We selected shooting method as a numerical solution. By using these methods of solution all solutions of the boundary value problem were obtained regardless of the choice of initial values. According to the results, following conclusions were made:
Numerical studies of this work show that the parameterization of the boundary value problem for nonlinear differential-algebraic equations, proposed in this paper significantly improves the computational algorithm of the shooting method and allows to find all solutions of the boundary value problem. Thus, in this paper we propose a numerical method, which allows solve the applied problems related to technology of machine building, rocket and space technology, aviation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhuravlev S. V., Zechikhin B. S., Kuz'michev R. V. Analytical calculation of magnetic field in active zone of synchronous machines with permanent magnets. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 197-209. Synchronous machines with rare earth permanent magnets are widely used in aviation and rocket technology as motors for the electric actuators and generators of electrical power systems. These machines are promising for use as the main aircraft generators with a high level of electrification in the DC power supply system of increased voltage 270 V. They are characterized by a large variety of designs, most important of which are versions with radial or tangential magnetized permanent magnet and nonmagnetic or bimetallic holder. Constantly increasing demands to the mass-energy performance of aviation synchronous machines with rare earth permanent magnets, to improve the quality of their designs, the development time and cost reduction are met by continuous improvement of design methods and design techniques based on the calculation and analysis of electromagnetic fields in their active zones. Rational combination for electromagnetic fields in active zones analysis is traditional methods based on the models with lumped parameters together with circuit theory and computer technologies of numerical finite elements analysis based on the models with distributed parameters and field theory. Traditional methods and created on their basis by way of setting relatively simple and easily observed mathematical interrelations between input geometry and windings parameters with output energy parameters new design methodologies allow quickly and solve the problem of initial active zone geometry of an electric machine and parameters of its windings selection with an accuracy sufficient for engineering analysis. We used numerical methods for electromagnetic fields verified analysis and optimization, where parameters obtained with traditional methods are set as the starting point. Traditional methods of synchronous machines design and machines with rare earth permanent magnets in particular are based on a number of assumptions and system of calculation coefficients linking the parameters of a real distributed active zone model with lumped parameters of electrical and magnetic circuits. For example, excitation field of synchronous machines is commonly characterized by a system of calculation coefficients κf, κф, αδ и κΒ, determined based on the analysis of excitation winding two-dimensional magnetostatic field or permanent magnets in the smooth working gap brought form the armature side with non-saturated armature and inductor magnetic cores.Saturation consideration is carried out, as a rule, by separate introduction of various correction factors. An effective method for determining the calculation coefficients of synchronous machines is the method of harmonic analysis of magnetic fields in active zones of electromechanical converters. The article presents new analytical solutions obtained for the magnetic field in the active zone of synchronous machines with rare earth permanent magnets by harmonic analysis. The problem of calculating the magnetic field generated by the permanent magnets of sector form with a constant direction and magnitude of magnetization, located between he two cylindrical ferromagnetic areas with infinite permeability was solved in polar coordinates system. The resulting solution allows determine the excitation magnetic fields and calculate coefficients of synchronous machines with permanent magnets of sector type, as well as prismatic and circular forms with their allocation on the rotor and fastening them with nonmagnetic holder, as well as reversed structure. Also, the problem of the magnetic fields calculation of excitation and armature reaction of synchronous machine with permanent magnets and a bimetallic holder with alternating magnetic and nonmagnetic areas was solved. The solutions presented in the article were checked by comparing the calculation results with the results of numerical finite element analysis. The results mismatch herewith does not exceed 1%. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dyakin N. V., Dyakin S. V., Volsky S. I. Power converter within the multi-agent system of a spacecraft power supply system. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 210-217. The spacecraft power supply system as well as ground-based power supply system provides transmission and redistribution of electric energy from power sources to consumers. One of the major requirements claimed to power supply systems is to keep electric energy at specified level in the course of one or more primary energy sources failure. Currently, two types of supplying electric power to consumers exist: centralized and decentralized. The structure of the centralized power supply system has the Central Switch Gear (SSG) that collects electric energy from all primary and secondary power sources. The main advantage of such systems is the stable feeding of consumers due to required power extraction from all electric power sources. On the other hand, the centralized electric power system has relatively low power grid mass and size figures, as well as comparatively low reliability due to the presence of single distribution gear. The prospective trend, with the presence of a number of primary and secondary power sources in particular, is implementation of decentralized electrical power supply system, having several small SSGs, which potentially increases reliability and scalability. The article introduced the concept of an agent and multi-agent power supply system that provide the operation, storage of information in the database, as well as exchange of information with other agents that allows implementation of the decentralized power supply system. Consumers, sources and energy storage units are the main elements of the system. We suggest designing a separate agent for each element, which will provide — functionality, information storage in database, as well as information exchange with other agents to provide their effective operation. We identified the following agents: a load agent (LA), an environment agent (ENVA), a photoelectric converter agent (PHCA), a fuel cell agent (FCA), a battery agent (BA), a simulation agent (SA) and a database agent (DBA). The article also presents a power circuit of a static electric energy converter based on modern RB-IGBT transistors and method for synchronizing the output AC voltage with other power sources. It allows improve conversion efficiency of the energy generated by solar cells (this is one of the agents of the decentralized systems), reduces the mass and size parameters of the converter. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tihonov A. I., Kalachanov V. D., Prosvirina N. V. Aircraft engine-building enterprises competitive stability enhancement in modern economic conditions. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 218-226. The article is devoted to the issues of competitive stability of Russian aircraft engine-building enterprises amid rapidly changing market demand. It stresses the necessity to develop a whole number of measures and the aggregate of product and process innovations aimed at quality improvement of output products; expansion of productive activity diversification level; carrying out the restructuring of companies of aircraft engine-building sector; entering world market as suppliers of 2nd-3rd level components; implementation of non-traditional finance-and-economy tools and schemes to provide an enterprises entering the world market as a supplier of competitive aircraft engines. The pressing problem for national aircraft industry is formation of globally competitive world-class engine- building sector. It is planned to increase budgetary allocations volume for aircraft engine-building at the expense of Federal budget from 1 billion 448 million rubles in 2015 to 3 billion 431 million rubles in 2025. With such a significant financing increase of the sector, the compulsive issue of competitiveness of the enterprises is challenged. This concept means time-phased competitiveness of the aircraft engine-building enterprises. We need to preserve gained competitive advantage as longer as possible, as well as raise a level of intra industrial cooperation. This will require the increase of economic responsibility of all parties for the results of their common labor and achievement of common goals. It will also require intensification of all manufacturing processes and enhancement of individual role of all structural divisions of an enterprise. The aircraft equipment life cycle is a significant and special component for the competitiveness analysis due to its scope of production and time parameters of implementation. Thus, organization of aircraft equipment competitive production should take these specifics concerning life cycle with allowance for upgrading possibilities, capital and restoring repair with allowance for assigned resource for components, assemblies and aircraft in whole into account. Mandatory elements also are maintenance and technical support as well as service maintenance of products when in use. Development and advancement of new products of the enterprise of the aircraft engine-building sector should be carried out with emphasis on international cooperation, allowing develop global chains of deliveries of their own and create strategic alliances with other aircraft building market participants, including efforts within the frameworks of core innovation territorial clusters' activities. Global servicing network that will help the companies of this sector to transfer to the full life cycle of the engines management is going to be created. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dmitriev O. N. Typology of conceptual schemes notation of multi-criterion management decisions optimization problems in aerospace sector . Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 227-232. The aerospace sector features a highly considerable specifics and types spectrum of management problems. Among these problems the presence of management decisions optimization problems is mandatory. Correspondingly, management goals in aviation and space-rocket sectors are diversified, heterogeneous in dimension, conflict and knowingly irreducible to a single utility measure. Thus, in all cases the multicriteriality occurs. A certain conceptual idea of a group of optimization criteria notations (interpretations) diversification has the right to existence. In various fields of mathematical modeling identification and algorithm presentation significant progress can be observed, which may lead to creation of tools allowing newly interpret management situations and find new solutions for management optimization problem, based on conceptually new mathematical methods, namely numerically or even of closed form. The requirements on presentation include: — Correspondence to the basic fundamentals of scientific cognition; — Universality with relation to number and conceptual definition of optimization criterions, as well as procedures applied for their evaluation; — Keeping the sequence of optimization criteria positioning; — Keeping the dimensionality of original optimization criterions; — Keeping mutual priority of original optimization criterions; — Ensuring representation additivity (componentwise addition feasibility); — Using such structures of scientific theories within which frameworks the inception of solving optimization problems methods is possible; — Vector optimization criterion applicability for correct scalarization procedure. The group of management decisions optimization criterions in aerospace sector can be represented (interpreted) by implementation of the following conceptual schemes: — Conceptual scheme based on the theory of sets. In this case, the original group of optimization criteria is presented in the form of a set K, such that the original optimization criteria are declared disjoint singleton subsets of this set: ; — Conceptual scheme based on linear algebra. In this case, the group of optimization criteria is presented in the form of a vector , such that the original optimization criteria are declared components of vector criterion: ; — Conceptual scheme based on the classical algebra. In this case, the group of optimization criteria is represented as a function K, defined as n-th degree polynomial of conditional argument A without constant term, such that: ; — Conceptual scheme based on the theory of functions of complex variables. In this case, the group of optimization criteria is presented in the form of functions K of complex variables with parameters , defined as a complex variable without the real part, such that: . It is obvious, that all abovementioned interpretations provide for the tend to the extremum, which is also a component (maximum or minimum). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Opryshko Y. V. Long haul passenger aircraft competitiveness evaluation model. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 233-244. Home producers of civil aerotechnics are not able to enter foreign market and almost ousted from the home market due to severe competition with foreign companies. One of the reasons for the present situation stems from the lack of methodology of civil aerotechnics competitiveness evaluation, which allows objectively determine level of competitiveness and the ways of its increasing. Research objective — developing of aircraft competitiveness evaluation model, which allows for all basic factors of cost and non-cost character. Employed methods — analysis methods, deduction and forecasting. According to our research, the existing approaches are not always effective. The proposed model searches for competitors, evaluates their advantages and disadvantages, makes a comparison of level of costs and takes into consideration passengers’ judgements. Thus, we evaluate the aircraft competitiveness at the market. The article motivates the necessity of comparing only the aircrafts with equal levels of both customer service and airworthiness certificates. The paper proves the necessity of airliners operating costs with minimum cost of flight per one passenger criterion, since only with this criterion gives the possibility to consider all operating costs, ICAO restrictions, differences between aircrafts passenger capacity and course speed. One cannot use the current price level for calculation of aircraft life span operating costs. We recommend use predictive values for POL price indices; cockpit and cabin crews labor costs, currency courses, airport charges rates etc. Thus, we obtain minimum dynamic flight cost criterion. With reference to passengers’ preferences, the author means their requirements of flight comfort, personal area, air conditioning quality, low noise level and high cabin pressure. Aircraft building companies can evaluate the competitiveness of their product using the described technique. The proposed model should be useful for airline executives, while selecting an airliner. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsova A. S. Development of external economic relations between Brazil and Russia (on the example of the aerospace and energy industries). Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 245-251. Since 1994 diplomatic and economic relations between Russia and Brazil differ in the positive dynamics of political contacts on all levels. October 2013 marks 185 years since the establishment of the Russian-Brazilian diplomatic relations. In a few last years and especially after introduction of sanctions directed to level deceleration of Russian economic integration into international arena, the relation between Russia and Brazil develops with the high rates. Most changes take place in the field of external economic collaboration, especially in the field of science (in particular, space programs), energy and finances. In opinion of Goldman Sachs, to the 2050 the summary economies of BRICS countries will exceed the total size of economies of the richest countries of the World (The Group of Seven). The set dialogue determines external economic partnership between Brazil and Russia. A primary goal is to diversify bilateral trade with the aim to lead its volume up to 10-11 milliard dollars in 2020. At the present time, Brazil continues the development of operational satellites SCD-1 and SCD-2, which were first launched in 1993 and in 1998 year respectively. An important area of cooperation is a joint modernization of the Brazilian VLS-1 rocket (so-called program “Southern Cross”), which is the Brazilian entry ticket to the club of space-rocket countries. However, nowadays in Brazil only the use of space developments in the field of telecommunication brings the financial return. Another area of cooperation between Brazil and Russia is the nuclear power industry. Today, Brazil has the need for energy. In the framework of the VII meeting of the Russian-Brazilian high-level commission on September 6, 2015 a Memorandum of Understanding between the State Corporation “Rosatom” and Nuclebras Equipamentos Pesados SA (NUCLEP), the leading company of the nuclear industry in Brazil, providing services in the field of heavy engineering, has been signed. New opportunities for enhanced cooperation between Russia and Brazil are opened through the Business Council of BRICS and there are already examples of successful cooperation projects in the energy sector, in particular, the localization of production of power equipment in Brazil. The growing interest in renewable energy sources associated with the steady growth of energy consumption, as well as increased emissions of greenhouse gases into the atmosphere. The main task of Russia is search of ways to increase the commerce and, as consequence, expansions of investment cooperation. The level of investments has noticeably grown for the last some years, possible risks here became significantly less, but also the time of reception of the first profit has significantly increased. It is connected with the enough limited home market of consumption in Brazil, where most part of the population lives below a level of poverty and only buys products of the first indispensability. Thus, manufacture orientation to the export trade is more preferentially. Conclusions Cooperation between Brazil and Russia develops fast paces. The important directions of cooperation between two countries are such high technology branches, as space branch and atomic engineering. During cooperation Brazil aspires to take the experience, saved up in Russia, for progress of own technologies. Also, the interoperability between two states in area of a science and formation, tourism and other branches actively develops. The Fundamental importance for both countries has regional cooperation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komarova A. M., Novikov S. V. Aircraft engine repair work flows optimization based on innovative labor potential updating in conditions of rate setting. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 252-258. This article is devoted to the realization of aircraft engines competitive recovery in the framework of the State program of development of aviation industry in Russia until 2025. It is proved that aviation engine-building belongs to the number of high-tech and knowledge-based industries, which development affects a number of vital areas of life and, in whole, the stability of the national economy. One of the important trends of economic efficiency and Russian aircraft engines competitiveness increase is to ensure their reliability on the level of foreign competitors. The urgency of the system of aftersales service development and repair time reduction through maintenance workflow optimization using progressive norms and standards. The problem of optimal division of labor should be addressed comprehensively, taking into account economic, organizational-technical and psychophysiological factors, which are closely related. Thus, the article describes the method of division of labor optimization in the organization of aircraft engines maintenance of using models of integer linear programming and network planning. The paper presents the results of the implementation of a method of optimizing the division of labor occupied with assembly operations for aircraft engine maintenance. Hence, the use of these innovations will allow provide uniform loading at the workplaces, reduce the number of workers and the complexity of final assembly. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zvyagintseva I. I., Khmelevoi V. V., Zueva T. I. Using a method based on fuzzy logical derivation for airlines internal risk management. Aerospace MAI Journal, 2016, vol. 23, no 1, pp. 259-268. Active realization of State programs of industrial and economic development of Russia in modern conditions of managing increases the need for ensuring more mobility of its population. In conditions of Russia, avionics can provide the most effective transportation of passengers with minimum time losses, and implementation of light helicopters in particular. For steady development of business in the sphere of rendering helicopter services in the territory of the Moscow region, it is necessary to provide the high safety level of air transportation. Safety characterizes the degree of security from impact of risks, internal in the first place. Safety is a basic significant meaning for risk management and ensuring the greatest possible degree of security of social systems from economic and anthropogenic impacts. The development of helicopter transport depends on a solution of the problem of development and implementation of modern techniques and technologies of risk management. In economically developed countries, the assessment of airline activities efficiency puts on the first place the security of its activities, rather than the profit made. The risk is considered herein as a market grade, which identifies to a great extent both the position, and competitiveness of the rendered service and its producer. The subject for the study is a risk management system while operation of commercial helicopters. As a result, the concept of risk management based on safety notion is suggested. The airline internal risk assessment tool is developed and tested, and the measures aimed at risk management system formation are elaborated on. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lepeshinskii I. A., Antonovskii I. V., Guzenko A. A., Zuyev Y. V. Boundary conditions effect of a nozzle-stream system on two-phase gas-droplet streams propagation. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 75-84. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorontsova V. L. On investigation of limit cycles behavior depending on the growth of aerodynamic parameter of orbital rope system motion in an elliptical orbit . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 91-99. The study of aerodynamics influence on the motion of an artificial cluster-satellite of two bodies is stipulated by the expansion of large extent orbital tether systems field of application. For such large space systems, aerodynamic effects are of a great significance. We have investigated the behavior of limit cycle for an equation of relative motion orbital cluster of two bodies considering impact of gravitational effect, aerodynamic pressure, airborne gradient and dissipative factors, depending on the growth of aerodynamic parameter a. We use the equations of interconnected motion with allowance for the forces of gravitational gradient and aerodynamic factors. We study the effect of aerodynamic parameters on the behavior of limit cycles. To carry out the research we implemented well-known methods of nonlinear mechanics: of Lagrange equations of the first kind method, phase plane method; points mapping method; theory of motion stability methods. The main qualitative effect of the rotational motion of the satellite in an elliptical orbit is the possibility motion chaotization. The atmosphere creates especially strongly effects the beginning of chaotization due to the exponential change of its density in an elliptical orbit. Even relatively small eccentricities can enable strong chaotization. For eccentricity values e = 0.001 and small values of the aerodynamic parameter a limit cycles are absent. The increase of aerodynamic parameter a leads to the emergence of limit cycles. For values of a fr om 4 to 45 there a limit cycle exists. The value of (( to which all points on the phase portrait roll down drops from 29.6 to 14.5. With a further increase of the parameter a (a > 45) lim it cycles disappear. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samsonovich S. L., Makarin M. A., Larin A. P. Design of an aircraft side-stick controller based on electromechanical power mini drives. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 7-20. Design of a side-stick control (SSC) of the aircraft is an important task, which is focused on improving the efficiency and convenience of pilot operation. In addition, application of SSC allows reduce the total weight of the control system. The paper carries out the analysis of present-day SSCs, describes the effect of added mass inherent to any SSC. It also shows the disadvantages associated with control priority characteristic to passive SSCs, and shows that active SSCs have a number of advantages over passive ones due to permanent synchronous operation. The paper presents the results of morphological analysis and synthesis of SSC development. It is shown that construction of SSC gimbal joint using two electromechanical drives placed over skew axes allows reducing weight and size figures, and implementation of double-reduction harmonic gear with rolling elements makes it possible to design hybrid control channels. It is found that application of double-reduction harmonic gear with rolling elements for power mini drives with output stage operating as differential mechanism allowing summing up motor and mechanical guide motions is expedient. The paper reveals that introduction of additional mechanical guide for manual control increases the level of pilots information awareness as well as flight safety level in emergencies. The paper contains the results of design, mathematical modeling and the appearance of the prototype. The model is based on dynamics of a drive system, taking into account dynamics of permanent magnet synchronous motors, robustness of the design and reducing gear, moments of inertia, and nonlinearities, such as reducing gear backlash and dry friction. The authors developed a number of algorithms of SSC operation in different modes and described the method of setting the control priority. It is shown that the presence of force sensors improves the functionality of the device. The paper outlines the structure and operation of the aircraft control system when SSC is in use, and shows that transfer to manual control in case of power-off is possible. The presented results demonstrate that using of hybrid control channels increases the flight safety level. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyutyunnikov N. P., Shklyarchuk F. N. On effectiveness of turn winglets using in the capacity of wing mechanization elements . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 21-31. Aerodynamic characteristics of large elongation straight elastic wing with turn winglets are analyzed. The discrete vortex method is used for determination of the aerodynamic load distribution. Mathematical model of the wing structure is developed using the bay method as a finite element method with enlarged elements of a thin-walled beam subjected to bending, transverse shear and torsion. These methods are used to solve coupled aeroelasticity problem. Aerodynamic load distribution for elastic wing and its divergence velocity are determined. Dependence of the aerodynamic characteristics from the winglet turning about longitudinal axis for some of its locations are analyzed. Aerodynamic symmetric and antisymmetric load distribution taking into account the turning of the winglets is considered in this paper. The winglets can duplicate and even execute the functions of the wing regular mechanization elements as ailerons. The use of winglets can be particularly efficient for small aircraft with large elongation elastic wings. For determining the aerodynamic load the wing is divided on small finite panels with one joined vortex and two end free vortexes of constant unknown circulations. Flow non-separation conditions are satisfied in one point of the panel. Using bay-method the wing is divided to bays by cross sections. The bay stiffness matrixes are determined using the theory of thin-walled beams. Displacements, angles of rotations, and twisting in the joints of the bays are considered as generalized coordinates. The total stiffness matrix is constructed by standard procedure of finite element assembling. As an example aerodynamic load distribution and divergence velocity are calculated for straight wing with turn winglets. The proposed technique makes it possible to estimate the efficiency of the turn winglet control by aerodynamic and aeroelastic characteristics of wings. Calculations executed for typical structure of straight wing with large elongation show that using of that winglets may be efficient tool for wing aerodynamic characteristics control. The winglets can act as ailerons to control the antisymmetric motion of aircraft. Using of the turn winglets evidently is most reasonable for light aircraft with rather compliant wings of large elongation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pravidlo M. N., Prokudin S. V. Assessment of economic effect at mathematical modeling of aerodynamic characteristics. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 32-37. The paper presents the method for economic effect estimation when using new computer hardware (compact super computer) to calculate aerodynamic performance of unmanned aerial vehicles (UAV). It vividly illustrates that computer-aided experiments (calculations) reduce drastically the amount of testing carried out in wind tunnel. By expert estimation of foreign specialists (USA, Great Britain, France, Germany, Israel), depending on flight mode and UAV configurations for which the aerodynamic performance is determined, the wind tunnel tests cost reduction is five times less and even more. In this case, the reduction of tube testing herewith does not lead to loss of volume of information, necessary for high-quality design. The paper presents the method for calculation of manufacturing process economic component to estimate the aggregate of required expenses and economic effect analysis of a research work on computation cluster design for numerical study of aerodynamic performance. As practice revealed, this method can be successfully applied for economic appraisal of the abovementioned research work conducted in 2013-2015. As the results of the selected method for economic effect calculation revealed, the expenditures connected with acquisition of a new compact super computer as well as carrying out mathematical modeling are rather significant. But they become justified compared to the number of blowing-downs in a wind tunnel and related explicit costs. For example, with six testing blow-downs in wind tunnel the expenses are equivalent to the cost of new equipment. Moreover, when the number of estimated six blow-downs is exceeded, the results of comparison show that compact super computer zone of effectiveness comes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panasyuchenko P. S. Selection of critical parameters of a single rotor scheme rotary-ring with swiveling steering gear. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 38-45. Requirements placed on modern perspective helicopters envisage not only vertical take-off, landing and hovering, but long-range cruise speed as well. Having the same engine installation, a rotary-wing can achieve high flight speeds due to optimal use of the main rotor, additional fixed wing and propulsion plant. Creating the lifting force, the wing unloads the main rotor, preventing the retreating blade stalling. Propulsion plant sets optimum fuselage attack angle when it does not create negative lifting force and has minimum drag. Implementation of jet engines to create helicopter propulsion force is not effective since they are not used during hovering. Thus, in case of using turboprops as cruise engines not the entire power of main engines is realized at high flight speeds. This drawback can be rectified by using one or more extra propellers, driven by common transmission. In case of single rotor helicopter propellers can be used for reactive torque compensation at low flight speeds. At high speeds reactive torque is compensated by vertical tail. The alternate method of propulsive force creation at high speeds consists in implementation of tilting the tail ""rotor. In this case, all the power of main turboshaft engines will be used at hover, as well as at high speeds, distributing between main and tail rotors. The main problem of rotary-wing design is selection of the wing and propulsion prop parameters. This problem was solved by parametric analysis using Mil Moscow Helicopter Plant flight simulator. Engine power and main rotor parameters were fixed, and wing area and propulsion prop thrust varied. For a single rotor helicopter with two VK-2500M turboshaft engines and take off weight of 11500 kg, additional 15 m2 wing should be used to reach maximum cruise speed 385 km/h. The main rotor autorotation is not an optimal way to achieve the highest aircraft performance characteristics. The main propeller should compensate fuselage drag. It needs 2500 h. p. for this purpose. The main rotor, with this, produces 70% of required lifting force for a horizontal flight and consumes 1500 h. p. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zolotov A. A., Nurullaev E. D. Efficiency upgrading techniques for assembly products of space-rocket equipment. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 46-52. The article considers design techniques for reliability and safety upgrade of space-rocket systems (SRS) operation. The authors have suggested the reliability demonstration technique of the systems when measuring operational integrity parameters, as well as solved the problem of SRS reliability demonstration control under amount of testing limitations. Information content of tests has been enhanced. The paper defines the areas of effective and bearable values of the parameters under study. Failure probability was evaluated for each parameter through coefficients of variation of effective and bearable parameters values and safety margin. Interval estimation was calculated to provide guaranteed result. Average margin value was evaluated using operational integrity values sampling. For the accepted level of confidence, lower and upper boundaries of reliability were calculated. The sampling can be arranged using testing results carried out in the course of experimental development. Thus, amounts of redundancy introduction provides SRS reliability requirements for the limited amount of testing. It is very important in relation to time limit. We suggested systems reliability demonstration technique during extra heavy testing, and solved the problem of SRS operational integrity control during contingency rating. Availability of redundancy of system parameters characterizing its operational integrity is suggested. Loading factor was determined on account of product operation in both effective and bearable modes. After extra heavy testing the lower boundary of reliability for the accepted level of confidence was determined using tables. Thus, the introduction of amounts of redundancy provides the SRS heavy testing reliability requirements. It is of prime importance concerning one-shot products. The paper suggests an SRS failure occurrence evaluation technique, and solves the problem of a bad product acceptance probability. The technique of SRS validity control parameters optimization is offered. The problem of optimum tests number determining with allowance for tests expenses and inspection error damage is solved. The algorithms using the offered techniques, which are illustrated with modeled examples, are presented. The received results can be useful for the design offices workers, research institutes, scientific and production enterprises during developing, as well as operation and maintenance of highly reliable SRS. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kim V. P., Grdlichko D. P., Merkur'ev D. V., Smirnov P. G., Shilov E. A. Study of stationary plasma thruster performance in operating modes with high discharge voltages. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 53-66. The paper presents the results of the study of SPT-100PM and SPT-140PM stationary plasma thrusters models characteristics. These models operated with different schemes of discharge feeding and high discharge voltages. The abovementioned models are the SPT laboratory models with external accelerating channel diameters of 100 mm and 140 mm, respectively, modified for magnetic shunt allocation inside the discharge chamber. They had reduced width of the accelerating channel and magnetic system optimized for operation with high discharge voltages. Tests of these models had shown that due to the abovementioned modifications we managed to reduce the negative impact on thruster performance of mass flow reduction while discharge voltage is increased, to provide moderate level of discharge power, as well as accelerating channel broadening due to discharge chamber walls erosion during continuous operation. It is also shown that:
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Kolodyazhnyi D. Y., Nagornyi V. S. Experimental studies of electric field impact on chemical composition of kerosene-air mixture products combustion. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 67-74. The efficiency enhancement of aircraft engines through quality improvement of fuel spraying and fuel-air mixture combustion is the question of the day. The results of experimental studies of properly induced electric field, using electrical facility affecting aviation kerosene (EFAK) at the fuel nozzle input, as well as chemical composition of kerosene-air mixture combustion gases were obtained. Based on the carried out analysis it is possible to draw the following inferences:
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Maximov N. А., Maluta E. V., Sharonov A. V. Automated system for aircraft failures recorded during preflight inspection recordkeeping . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 85-90. At the majority of enterprises running aircrafts a considerable part of documentation is prepared in paper copies: maintenance schedule, units data, service bulletins, updating information, technical servicing manuals, spare parts and units lists, their certificates, logbooks, aircraft operating time information etc. With such immense information volumes in the form of bulky paper copies the process of search, selection, filing and adding new data represents a time-consuming operations. Solving the above-mentioned problems requires development of a software and its practical application in the system of technical servicing of aircrafts. As a whole, implementation of a software in the field of provision of technical servicing will significantly enhance the efficiency of aircraft utilization. The paper presents the developed software allowing carry out in full the recordkeeping of all aircraft failures in electronic format and issue scheduled reports on detected failures and their processing in accordance with domestic regulatory documents. Its distinctive feature consists in realization of 3D model of an aircraft in mobile application synchronizes with identical model allocated in the server. It is very easy to mark on it the damages revealed during the inspection. A photo of this damage together with its characteristic is transferred to the server, and logged in trouble record log. The developed software — is a mobile Android application encompassing all main steps of aircraft failures control: from failures journalizing to accompanying documents generation. In general, implementation of such software in the area of servicing provision will significantly increase the efficiency of aircraft utilization and servicing, which will contribute positively to flight safety level. The developed software was realized in ASYPOLA system. It is consisted of two subsystems: Android_part and Personal_Computer_part solving the following problems: automated failures recordkeeping, gathering, storing and filing of information, substituting paper copies. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nosov A. S. Power electromechanical drive based on planetary roller-screw gear of improved accuracy . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 100-107. The author chose power electromechanical actuator drives based on planetary roller-screw gear (PRSG) of improved accuracy and reliability of operation of the special equipment for integration installation of large-sized with and large mass products with a rocket carrier of a super-heavy class as the object of study. The technique includes the preparation of the initial data and the basic requirements to the actuator, an electromechanical drive circuit design. It also considers selection of materials and heat treatment of the main parts of the mechanism, the selection of lubricant, the design of the actuator, a preliminary calculation of the transmission efficiency, as well as power and kinematic analysis of the transmission. It allows calculate power losses in the mechanism, and adjust the calculation (if necessary), creation of a model to determine the main characteristics, checking compliance of transmission with specifications, comparison of the options and selection of the optimal one, the creation of the final model, test strength calculations, preparation of design and technical documentation. As long as power electromechanical drive is a vital unit with high requirements to accuracy of manufacturing of certain elements, the solid-state modeling with adjustment at each stage is necessary. The solution of such problems is made difficult without the use of through-design CAD / CAM / CAE systems. To ensure the required speed and accuracy of the output displacement of the electromechanical actuator we use the actuator with high reduction and efficiency. This is planetary roller-screw with a number of advantages over conventional transmissions:
The basic elements of the transmission are as follows: screw nut, threaded rollers, toothed crowns, separator, locking rings. Both screw and nut can be the key element in this transmission. Screws and nuts have a thread of triangular shape with an apex angle of 90(. Rollers have a special thread which profile in axial section has the shape of convex arcs of a certain radius, due to which a point contact is provided in conjunction with the roller screw and nut. The design of such transmission allows for different angles of helix of screws and nuts. Justification and development of scientific and methodological apparatus, and creation with its application of electromechanical drive with planetary roller-screw transmission for space nosecone tilters of a space-rocket carrier of super-heavy class allows improving the process of preparing a space-rocket carrier for launch. Improving the process of space-rocket carrier preparation for launch means increasing accuracy in reproduction of the ground tests program with regard to the laws of nosecone motion and allows reduce the possibility of emergency situations due to incorrect operation of the installed equipment and machinery of a space nosecone at the boost phase. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bobylov A. A., Belashova I. S. Variational formulation and numerical algorithm for the structural non-uniform surface wear-out by rigid punch problem solution . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 108-118. The paper considers a flat contact problem on an elastic half-plane with structurally non-uniform surface wear-out by the rigid wear-free punch. While stating the problem we suppose that elastic characteristics of the material are structurally tolerant and identical in all points of the body, and parameters characterizing wear- resistant properties of the material depend on the value of linear wear. We also suppose predetermined the main vector and the main moment of force applied to the rigid punch. To solve the contact wear-out problem under consideration we implemented variational approach. As a result, we obtained the problem formulation in tensions in terms of the system of quasivariational inequality of evolutionary type and first-order differential equation. For the problem time sampling, Euler explicit difference scheme was used. Thus, to determine contact pressure an elliptic inequity or extremum problem equal to it should be solved on each time step. We performed the problems quantization over spatial coordinates using the space of integrated fundamental solutions of the Flamant on the effect of normal concentrated force over the surface of elastic half-plane. We used boundary element approach to plot the surface of integrated fundamental solutions. Elements with a uniform distribution of contact pressure were used. As a result of sampling we formulated the problem of quadratic programming with restrictions in the form of equalities. The linear transformation of variables, allowing simplification of the restrictions was suggested. For numerical solution of the problem we used a variant of conjugate gradients method taking into account specificity of restrictions. The calculations carried out showed that structural heterogeneity over the depth of the wear-out surface significantly influences the nature of the interface wear-in process. The developed computational algorithm can be implemented for study of the efficiency of various technologies for superficial hardening by the method of computing experiment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dang T. P., Diveev A. I., Sofronova E. A. Network operator methodto solve the problem of identification control synthesis for mobile robot . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 119-128. The paper considers a problem of identification control synthesis for mobile robot. The problem emerges in cases when it is necessary to solve the problem of the control system synthesis for an object, which mathematical model is completely unknown. Examples for the occurrence of such a problem while robot guidance may bepresented as follows: the presence of an object described by a highly complex mathematical model; problems for which the use of the model in full is not necessary, or mathematical model of the robot is not known completely due to external, environment, as well as in case of partial loss of functioning. In this paper, we use a numerical method of the network operator to solve the problem of identification control synthesis for mobile robot. This method allows determining the structure and parameters of mathematical expressions in the form of integer matricesusing evolutionary algorithms. The main advantage of this principle consists in using small variations of the basic solution. The principle lies in the fact that the researcher defines one basic solution, and the evolutionary algorithm searches for the optimal solution on the given set of basic solution variations. This approach allows building a set of possible solutions, where the majority of the functions satisfy the condition of the control goal. The principle of small variations reduces as well the searching range, limited to the vicinity of the basic solution. In the process of searching, basic solution is periodically substituted by the best current solution. The network operator method was effectively used to solve various problems of synthesis and identification. The problem of identification control system synthesis consists of two tasks: identification of mathematical model of a controlled object and a control system synthesis for the obtained model. Initially, we apply the network operator method to solve the problem identification, in which, the quality criterion is a trajectory deviation from the experimental data. The experiments were performed on the real object, using the control, close to the required for control system synthesis problem. At the second stage, we solve the control system synthesis problem by the network operator method as well. We use another network operator of different dimensionality and with different quality criteria. We realize the network operator obtained as consequence of synthesis in the control unit of the real object and verify the results of identification control problem solution. The results of conducted experiments displayed satisfactory quality of identification and control synthesis problem solution. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov S. B., Kharchenko I. A., Averin S. V., Lavrinovich A. V. Unitized switched mode converters for aircraft on-board electric power complexes . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 129-141. Schemes of so-called pulse-modulated multilevel voltage inverters with output sine wave, three level (3L NPC) in particular, widely spread thus far, both in home and foreign publications on power electronics. Such inverters are implemented in the devices operating at high switching frequency and requiring high efficiency (low switching losses) and high quality of output energy. Such devices require also low harmonic content and corresponding to it noise emission with acceptable mass and dimensions, dynamic and reliability parameters of output filters, such as uninterruptible power supplies (UPS), solar batteries inverters, onboard frequency converters, etc. Three level inverter cell (totem pole) of three-phase off-line voltage inverters with output sine wave represents traditionally a half-bridge pulse modulator based on input two-capacitor structure with grounded center tap (for three phase variant in particular). It also consists of unidirectional four-switch transistor structure with free-wheel and grounding diodes, and output LC circuit. The output LC filter (Lf-Cf) acts as demodulator (low-pass filter). Depending on its parameters relationship it provides various dynamic time lag and degree of robustness (slope ratio) of inverter output volt-ampere characteristic near its operating point. Conduction losses in three-level inverter (3L NPC) are slightly higher, than are those in two-level one. However, three-level inverter provides significant switching losses reduction and allows decrease total power dissipation by 40%, which is especially impressing at high switching rates. SEMIKRON company manufactures SEMITOP & MiniSKiiP dedicated modules based on IGBT intended for invertors design within power range up to 100 kVA. Their structure provides all traditional protection circuits: overvoltage, overcurrent, short circuit and overheating. Moreover, in contains circuits for power switches turn-off in case of through-currents occurrence and active voltage limiting of the power switches. As an essential shortcoming of methods and means of protection, implemented by the company, we should mention traditionally straightforward approach of foreign companies, according to which they proceed from invariable structure of the power stage (without any attempt to its revising). They pay attention only to control scheme and forming switching trajectories by control signals parameters. Thus, the designers fully neglect theoretically substantiated and tested in practice means, such as soft switching and overcurrent and overload protection, as well as switching heat losses and noise emission reduction. These means are: inductive and capacitance non-dissipating (energy) damping and snubber circuits (DSC), which guarantee switches zero-current turn-on and zero-voltage turn-off. Moreover, there are no attempts to exclude circuits for possible through-currents and inverse diode over currents, disregarding the possibility of their impact of powerful EMI of lightning on driver circuits (regardless of logic circuits of guaranteed pauses etc.). Another, no less substantial drawbacks, typical to this approach, are the following established traditional approaches to equipment design. They are: a) implementation of input energy-consuming capacitive filters based on electrolytic capacitors with rather low reliability factor (thermal stability, durability, life cycle); b) the lack of inverse current gain-phase adjustment circuits (both for idle and regenerative current), running in a rectifier mode and a corresponding power factor correction, significantly reduced due to AC filtering inductor (ballast) and switching rectifying action; c) implementation of step-down invertor and rectifying modes only, significantly narrowing functional features of conversion (the input-output voltage ratio range); d) low output electricity quality of output power (output voltage form and parameters stability). All above mentioned features do not allow implement well known inverting and rectifying converter circuits to realize universal module design and module-scalable architecture. With reference of all above said the authors of the paper think that the attempts to implement the circuit design means leading to increasing production and operational effectiveness of so-called bidirectional inverting and rectifying converters (BIRC) do not exhaust themselves. The paper represents the examples of some possible approaches to the matter by means of radical BIRC power circuits upgrade, protected by RF priority. The original approaches to radical modernization of the traditional three-level sinusoidal voltage inverter proposed in the article are applicable for the design of unitized modules of bidirectional (convertible) inverting and rectifying (or else, rectifying and inverting) converters (BIRC or CRIC) with demodulating and storing reactors, power factor correctors and non-dissipating damping and snubber circuits (for soft switching aimed at reliability and efficiency increase and noise emission reduction). These circuits can be recommended for the design of unitized modules meant for the synthesis of multi-functional (multi-phase in particular) switched mode converters (MSMC) with functions of direct BIRCs, CRICs, convertible frequency converters (CFC) and switched mode converters, regulated sine currents and voltages inverters (RSC/VI), uninterruptible power sources (UPS) and other types of converters for electrical complexes of module-scalable architecture, which provides high production, assembling and servicing processability, as well as high energy saving, reliability, weight and size and price effectiveness, as well as high quality of power and EMC factors. This article seems to be interesting to a wide circle of designers of power electronics, especially in the field of aircraft on-board energy supplies, and for designers of fully electrified aircrafts in particular. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhegov N. A., Kirillov V. Y., Klykov A. V., Tomilin M. M. Comparison of design and experimental frequency response of shielding efficiency of on-board cables for flying vehicles . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 142-148. Purpose The flying vehicle on-board cable network is subjected to electromagnetic interference due to its length. Electromagnetic interference immunity and susceptibility of on-board systems strongly depends on the on-board cables shielding efficiency. It is one of the main characteristic of flying vehicle on-board cables. When conducted current induced by electromagnetic interference flows over the external surface of shielding cover, the shielding efficiency is evaluated on the basis of well-known frequency response of coupling impedance. Coupling impedance of shielded cable can be calculated based on theoretical models or found experimentally with co-axial test setup. Coupling impedance models of shielded cable differ due to various approaches of describing the physical phenomenon of the in-phase voltage inducing in inner conductors of the cable, when current flows through external surface of shielding cover. Frequency responses of coupling impedance models differ from each other, which leads to the deference of frequency responses of external shielding efficiency, calculated on their basis. The goal of this work consists in studying of coupling impedance models of on-board cables for flying vehicles, their divergence at the specified frequency range and comparison with experimental characteristics obtained using co-axial test setup. Design/methodology/approach The theoretical part is based on classical electrodynamics and electrical engineering. Elements of the complex variable theory and operational calculus were used as well. Findings The paper presents the results of theoretical and experimental coupling impedance and shielding efficiency frequency response of on-board cables for flying vehicles plotted in MATLAB. It also studies the differences between theoretical and experimental coupling impedance and shielding efficiency frequency response at specified frequency range. It is marked that shielding efficiency frequency response is valid for case of conducted current flows through the cable shielding cover in the absence of external electromagnetic field. In computing shielding efficiency the current through shielding cover must be of conductive origin rather than induced by the field of an external noise, i. e. it can be, for example, a reverse receiver-to-source current in case of non-symmetric connection. If a current through external shielding cover is induced by electromagnetic field effecting the on-board cable, the calculation of shielding efficiency based on coupling impedance frequency response can lead to significant erreos. Current, which flows on cables shielding cover, should be conducted electromagnetic disturbance when shielding efficiency is calculated. For example, this current could be common-mode return current from the receiver to the source. Shielding efficiency calculation based on coupling impedance frequency characteristic can lead to significant errors in case the conducted current induced by electromagnetic field. Completeness of the reseaerch The presented paper is a part of the research on calculation of electromagnetic interferences induced in on-board cables of flying vehicles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Andreev A. K. Ponderomotive forces in «axially magnetized torus - soft magnetic orb» system . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 149-158. The field H(r,z) of axially magnetized torus in the vicinity of its axis of symmetry Z has been numerically studied. It is shown that the profile of the field allows construct a simple mathematical model to determine ponderomotive forces in the torus — orb system. Unloaded (in the absence of external forces f = 0) soft magnetic orb in the field of the torus has three equilibrium positions near Hmax: in the center of the torus, over the torus and under the torus (areas C, A and B, respectively) — Fig. 1
Stable position of the orb under the load f is realized under condition of dH(r,z)/dz < 0. Integral equation for orb magnetizing can not be solved by such model, since it assumes a simplified calculation of the orb polarization in the field of the torus with surface charges averaging over two hemispheres of the orb, and solution of the forces affecting magnetic charges of these hemispheres. The model allows further simplification by introducing into consideration of effective magnetic charges located in the center of gravity of the hemispheres charges on the Z-axis. The forces acting on the point charges are calculated. Effective charges provide the charge neutrality of the orb. In this manner, the model is reduced to one-dimensional model. The model simplifies the calculations without loss of accuracy. Radial r-component of the field of the torus is much smaller than Z-component. —component of the field H(r,z) is relatively linear in the computation domain. It serves as a basis for the introduction of the one-dimensional model. In this paper, the calculations were made for the torus of the size of 9,7 × 4 × 1,25 cm. The magnetization of the torus is set to Mz = 915 emu/cm3. The saturation magnetization of the orb is set to Mz = 1620 emu/cm3. The diameter of the orb is 2R = 1,15 cm, the gravity weight is equal to 6,121·103 dyne. The displacements of the orb under its own weight relative to the unloaded orb: in the area A — ∆A = 0,353 cm, in the area B — ∆B = 0,741 cm, where ∆A < ∆B . The maximum values of ponderomotive forces, at which the position the of the orb is steady, in area A — FAmax = 2,072·104 dyne, in area B — FBmax = 6,846· 103 dyne. The ratio of the maximum forces in the areas A and B is equal to: FAmax/FBmax = 3,027. When |f | > Fmax, an abrupt reposition of the orb occurs: fr om area A to area C, and from areas C and B to (- ∞). Levitation ranges in the area A — ∆A = 1.164 cm, in the area B — ∆B = 1.217 cm, wh ere ∆A < ∆B Displacement of the unloaded orb relative to the maximum value of the field is equal to: +10-3 cm in the area A and −103 cm in the area B. The area C is not considered in this paper. Numerical calculations explain the experimentally observed significant difference in the displacement of the orb in the field of gravity and maximal forces FAmax and FBmax above and under the torus. When the diameter of the orb is greater than it reaches the area of the sign reversal of the torus field, and the maximum value of the force is not defined in the model. The experiment showed that the ratio of maximum calculated force Fmax to the force measured in the area A is equal to 1,37. It is obvious that the accuracy of the model increases for the samples of smaller diameter. Taking into account the given above data it can be concluded that the model can be implemented for semi- quantitative evaluation of the power characteristics of the system torus-orb. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Schetinin V. E., Averin S. V. Output voltage of multi-phase inverter with sine-wave approximation of switching cells generation algorithm . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 159-167. Operation algorithm of traditional multi-phase inverter structuresfor multi-level output voltage formation assumes consecutive summing of voltages from individual cells along the period of the function. According to the proposed algorithm, sinusoidal reference signal is divided into equal voltage levels in accordance with the number of inverter cells so that the output voltage approaches sinusoidal waveform.Then we determine the intersection points of voltage levels with the sinusoidal signal and time intervals for each level.The increment valueof voltage levels is the same. It depends upon the number of cells, and only the durations of each level vary. As aresult we obtain approximated sinusoidal signal. By increasing the number of cells, the output voltage approaches the form of the reference sinusoidal signal. Each time interval of a voltage level operation is divided into equal intervals, according to the number of inverter cells.Then, using the proposed algorithm of power switches commutation, we obtain the total voltage of each level by summing voltages of all cells both in serial and in parallel. This algorithm allows uniform distribution of the loads of all cells, which, in its turn, allows using similar cells for multilevel inverter.Other well-known schemes for formation of an approximate sinusoidal output signal does not provide an equal cells load. The proposed algorithm of operation of power switches of cells is clearly structured, and allows commutation scheme scalingfor any number of cells.Theoretically, the maximum number of cells of a multi-phase inverter depends on the minimum switching time of a single power switch, comprising a cell of an inverter. The study of simulation results show that there are practically no low-order harmonics when the number of cells equals to six. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Oskirko V. O., Semenov V. D., Pavlov A. P. Snubbers implementation for magnetron sputtering systems switched mode power supplies . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 168-176. As a rule, high frequency switched mode power supplies (SMPS) are used for reactive magnetron sputtering [1 3]. The point is that such pulse powering allows reducing the probability of electric arcs occurrence and increases stability of reactive magnetron sputtering process. One of the main parts of SMPS for magnetron sputtering systems (MSS) is a transistor former of output pulses. It determines the power source type (unipolar, bipolar, HIPIMS) and its operating efficiency. As is well known, in contrast to continuous input current mode, switching losses, peculiar to switched mode limit maximum switching frequency, and subject transistors to pulse overloads decreasing the reliability of a pulse former. If soft commutation of transistors is provided, zero-voltage or zero-current switching will allow reduce dynamic losses in transistors and increase reliability of a pulse former. Reference [4] presents modular SMPSm based on bipolar pulse former (BPF), where soft switching was provided by using snubbers, limiting the current or voltage growth rate during transistors switching. However, to ensure correct operation of snubbers as a part of BPF their adjustment is necessary, with allowance for real parameters of components in use and BPF operating algorithm. The present work is devoted to solving this problem. In the course of this work, we developed a computer model of BPF in Swicher CAD/LTspice, based on standard SPICE models of power electronic components. With the help of BPF model, we calculated parameters of snubber elements, necessary to ensure soft switching conditions and energy recovery stored in snubber elements. In addition, the energy efficiency of BPF with snubbers at the maximum frequency of the output pulses forming of 75 kHz was calculated. The calculation results showed that the use of the snubbers allows reduce significantly switching losses of transistors. Due to energy recovery, stored in snubber components, we managed to reduce the total power losses of BPF by 25 % and increase pulse former efficiency by 0.6 %. Switching losses reduction of transistors provides increased ВPF reliability, which together with higher efficiency offers a prospect of a further increase of the output pulses frequency and improved stability of reactive magnetron sputtering process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chernykh N. A. Risk assessment at the stage of foundation of a small innovation enterprise in gas turbine engineering . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 177-187. The paper considers some specifics of small innovative enterprises foundation in Russian gas-turbine engineering. The percentage of small innovation enterprises (SIE) that pertain to the space-rocket hardware and gas turbine equipment in Russia is currently low. This can be explained by the fact, that commercialization of the results of scientific research in such a science-consuming industry as gas turbine engineering, where prospects are of no guarantee, presents high risks. The author considered the example of a small innovation enterprise foundation in Russian gas turbine engineering with participation of a large gas-turbine engineering company and venture capital. SIE 1 has for its object development and commercialization one of the advanced competences in the sphere of parts design, development of industrial technologies and short-run production for gas-turbine engines. At a project startup stage in gas-turbine engineering, Russian practice is characterized by common mistakes, which may turn into a real threat of risk situations occurrence in the sequel. These threats involve insufficient presentation; incompleteness of the products and services; the absence of unbiased price-quality relationship; low efficiency of labor caused by its wrong organization; ignoring legal questions of the case; irresponsiveness for the project executing; input barriers and volume of investment underestimation. The set of methods for economic risk assessment, suggested by the author, allows get reliable information about the risk in tome. Such information is necessary for risk management, and can be recommended to assess investment qualities of investment objects during foundation of innovative small economic environment of Russian gas-turbine engineering companies. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsova A. S. Perspective trends of Russia foreign economic cooperation with Latin America & Caribbean region . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 188-192. Since 2005 the Russian — Latin American commodity turnover increased twice and by the end of the 2015 first quarter totaled 17.8 billion USD. Latin America is the only region of the world, for which the increase in Russian exports is observed. The goal is to consider the problems that arise in the process of cooperation between Russia and the LAC countries in the region, factors that have a direct impact on changes in the external economic relations of today, as well as to determine the prospects of their development. The subject of this study is external economic relations, which determine the state of the level of interaction between the states, regional groups and other parties of the world economy, gives the opportunity to defend the interests of other States in the field of economy, as well as identify some of the theoretical aspects of international relations. This defines the range of problems underlain the presented research and its structure:
High practical relevance of the theme is stipulated by the great interest to the issues of foreign economic cooperation between Russia and the LAC countries, which do not hold a strong position at international import and export markets yet. Analysis of these issues has both theoretical and practical significance. The scientific novelty of this study is as follows:
The field of application of the results may contribute to the development of a number of measures at the state or municipal structures level for the development of foreign economic strategy with the involvement of practically poorly known regions of LAC. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Benderov V. V., Popov E. V., Savinich V. S., Sosunov Y. A., Shvedov A. G. Corporate development plan and scientific and technical section. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 193-199. To sustain at present the leadership in the field of national aircraft engineering in the interests of design and serial production of new types of aircrafts the corporate development plan, including long-term ones, should contain such items as creation and development of modern design department and production, which operate using digital technologies, the newest software, up-to-date test-bench and laboratory base and new flight test cluster. The strategic development way of an enterprise is formalized in the form of a complex long-term planning of technical development with due regard for the existing material, technological, information and human resources. The current annual development planning (the nearest project) and a three-year planning (medium-term project) are formed based on this long-term planning. Nowadays an urgent problem of defense manufacturing divisions modernization and their provision with skilled personnel revealed itself in full scale. Furthermore, it is noted that the scientific and technical reserve of Russian enterprises of the defense industry complex is almost exhausted. Therefore, the complex strategic development project should include long-term planning to establish the scientific and technical reserve and preparation of skilled personnel to maintain and improve technical, technological and intellectual resources of an enterprise. Human resources development as well as specialists training are among the main the priorities of JSC Tupolev. Andrey Nickolaevich Tupolev, the founder of the company Tupolev, has shown a great example of the strategic thinking and realization of advanced ideas. He relied on the existing scientific school as one of the elements of the strategic planning. The enterprise hasn’t lost this accumulated scientific and technical experience, but nowadays its not sufficient. Only new knowledge, skills and administrative qualities can ensure the success. It is necessary to know the state-of-the-art management and marketing tools. The necessity to preserve the succession of the majority of structural and engineering solutions when transferring from one aircraft type to the other improved types of aircrafts should form the basis of PJSC Tupolev and other modern aviation and production organizations strategies. It is also necessary to cooperate with fundamental and applied sciences organizations, which form the main scientific reserve of the industry and participate in the tests of aircraft samples under development. To implement strategic development projects of the enterprise we suggest form a group (or department) of highly skilled professionals. The main missions of such group will be acquisition and analysis of the existing scientific and technical information, participation in the carried out research works within an enterprise, organization and systematization of development and implementation process of industry technologies, long- term development planning related to the aviation science and technology. Strategic development plans implementation should allow the design engineering center enter a new scientific and technical level, enable to design, develop and realize tests of the modern competitive aircrafts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Opryshko Y. V. Substantiation of a long-distance aircraft operating costs dynamic assessment criterion. Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 200-207. The main indicator of an airline carrier competitiveness is air tickets low sale price as long as safety and comfort standards are observed. Accordingly, aircraft manufacturers face an urgent problem of producing an aircraft least-cost in operation. The existing operating costs assessment criteria do not allow for environment versatility, ICAO restrictions, various passenger capacity, and other factors. It leads to unacceptable errors when assessing passenger plane operating costs. The paper pursues an objective of developing a criterion, considering prime operating costs, ICAO restrictions, various passenger capacity and course speed, as well as environment inconstancy. According to ETOPS regulations the flights of the planes equipped with two gas-turbine engines must be performed in such a way that in case of the failure of one of the engines the flight duration with one operating engine to an emergency airfield from any flight way point under conditions of zero wind and speed set for the flight with only one operable engine would be 60 minutes for non-ETOPS aircrafts, and up to 270 minutes for Boeing 777. Thus, the only true criterion, which is able to assess a long-distance passenger plane operating costs objectively, is flight cost value per one passenger. The cost of one ton of the fuel, labour cost of flight technicians, flight crew together with flight attendants, currency rate, airdrome fees etc. are not constant over the total lifespan of an aircraft. Thus, there is a danger that the flight cost value indexes would display unacceptable error when comparing aircrafts with differences in performance and economic characteristics. Thus, to assess operational costs objectively we recommend use dynamic cost value as criterion, which is calculated, not at the current level of fuel and lubrication materials prices, labour costs of flight attendants and flight crew, currency rates and airdrome fees stakes etc., but based on average predicted values over the total lifespan of an aircraft. The obtained value of dynamic price value of a flight per one seat is of probabilistic nature and has a certain default level associated with predictive values of a certain number of indices. However, the accuracy of cost accounting in this case would be much greater, than when using static cost value of a flight hour, or the cost of either ton-kilometer or passenger-kilometer. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Melik-Aslanova N. O., Moskvicheva N. V. Aviation industry enterprises production capacities modernization specifics analysis . Aerospace MAI Journal, 2015, vol. 22, no 4, pp. 208-213. To carry out production capacities modernization at aviation industry enterprises one needs motivated buildup and approval of the investment policy. It includes the following basic stages:
1. The first stage — analysis of financial and economic activities of an enterprise, market outlet and competitiveness of manufactured products and assessment of production capacities condition. At this stage, we determine the degree of moral and physical depreciation of basic production assets, and the line of activity selection to provide the necessary equipment including:
2. The second stage focuses on the selection of the most significant projects, determination of the total volume of required investment resources. We recommend carrying out the analysis of the sources of investment resources with an allowance for the complexity of funds raising. The attraction of additional monetary resources with the use of credit and stock markets is proposed. Based on the stated structure of investment capital for production capacities modernization, the determination of modernization of production capacities efficiency indicators, which the enterprise should approach, is realized. Feasibility report of the project is included into economic mechanism of modernization of production capacities investment policy. A special role in managing the implementation of the investment policy is assigned to the achievement of the required efficiency indicators of the implementation of production capacities modernization and the return on investment. For this purpose, it is expedient to carry out the justification of the need for investment resources considering economic indicators that reflect the costs of their involvement. Calculations of the technology for justification of sources of investment resources application for production capacities modernization at the enterprises of the aviation industry efficiency include:
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Pisarenko V. N., Vasil'eva I. A., Kulikova M. S. Specifics of flight execution in the vicinity of an airport . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 40-46. The execution of flights in the vicinity of an airport area in Russia differs from flights execution abroad. Before flight, Russian pilots set the airfield pressure on all barometric altimeters, the so-called mode of an airplane aviating according to the pressure over the airfield — QFE. Take off, After takeoff and circuit the altimeters are set to standard mean sea level pressure of 1013.2 hPa (760 mm. Hg) — QFH. This is the mode of airplane aviating according to pressure of the sea level. After taking a decision on the height of the flight execution of the flight at the set level begins. During preparation to landing after the plane descends to circle height, all barometric altimeters are set to the pressure over the airfield. After landing in QFE mode, the altimeters indicate the altitude of zero meters at the airfield. Barometric altimeters do not change pressure indication all over the world world. While in flight at the level and at landing, barometric altimeters are set to standard pressure of 1013.2 hPa (760mm. Hg) and the whole flight is executed in the QNE mode at the height relative to mean sea level pressure. At the airfield, barometric altimeters indicate the remaining altitude relative to sea level. Pilots should know it, and take into account the location of every airfield relative to sea level. The change of pressure in barometric altimeters results in errors and failures in interacting systems, such as system of automatic flight control, system of the early warning of dangerous closeness of earth of GPWS, system of warning of collision of airplanes of TCAS control the and signal permutation pressure due to height-indicators entered as barometric flight altitude. GPWS (EGPWS) provides radio altitude signaling. The change of pressure in barometric altimeters in the course of the flight is dangerous, and may result in a catastrophe at an attempt to go around in automatic mode. It happened in Kazan in 2013, in Perm in 2008 — at go- around of the airplane Boeing-737 in the automatic mode instead of circuit circling, when the set of height was translated to the autopilot. Eventually it resulted in a catastrophe. For absolute promotion of safety, it is necessary to bring about the changes in the normative document of civil aviation of Russian Federation FAR-128 and oblige a crew to execute the flight on all stages only in the QNH mode. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoilovskii A. A., Liseitsev N. К. Methodology of design parameters characterization of solar-powered unmanned aerial vehicles . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 7-16. The goal of the work is creation of the methodology of the solar-powered UAVs design parameters characterization. The task of the solar-powered flight vehicle designing as well as any flight vehicle implementing aerodynamic flight principle comes to fulfillment of fundamental equations, that describe any projected plane as heavier than air flight vehicle with ability to fly in a certain altitude envelope and velocity range, make evolutions, take off and land at established class airfield. Design problem of a solar-powered flying vehicle as well any other flying vehicle, realizing aerodynamic flight principle is reduced to design parameters characterization, which define any designed aircraft as a heavier-than-air flying vehicle able to fly in a predetermined flight altitude envelope and speed range, maneuver, take off and land at airfields of a certain class. The main of these relationships are as follows: mass balance equation; gravitation balance equation; power balance equation, as well as stability and balancing equation of an aircraft. In mathematical formulation of the problem, the design means meeting the above- mentioned requirements, considering the imposed constraints on either parameters, or characteristics. Solar-powered UAV design has some peculiarities due to the specific type of power plant. The suggested methodology defines weight and geometry of solar-powered UAV depending on payload weight and power consumption. The methodology based on comparatively limited weight, obtained in consequence of gravitation and energy balance equation, and real weight, obtained from mass balance equation. For more precise weight calculation, we create new weight models of aircraft elements. The aircraft parameters restrictions are included in the methodology due to atmosphere turbulence. The methodology can be helpful as well in forecasting of solar-powered aircraft development if we take into account advanced technologies. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Evdokimenkov V. N., Kim R. V., Vekshina A. B., Yakimenko V. A. Study of pilot's control actions personality during landing based on neural network models. Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 17-29. The paper considers an approach to developing pilot's control actions models during execution of typical flight modes. Implementation of such kind of models for the structures of pilot's backup systems will allow providing the possibility of parallel solution of task complex, aimed at pursuing an objective of a concrete flight mode. The results of landing trajectories processing are reported. These results indicate that both aircraft trajectory parameters distribution and control parameters distribution during landing performed by various pilot's reveal statistic significant differences. This fact allows us to say that efficiency of upgrading of pilots actions support systems requires provision of possibility to adapt implemented models of pilots control actions, taking into account experience, qualification and peculiarities of control actions of a certain pilot. We suggest an approach to forming individually adapted models of pilot's control actions based on neural network of a multilayer perceptron type. Such kind of model uses actual parameters of aircraft-pilot system status as input variables, including dynamic and control parameters. The output of neural network model considered in the paper is scalar indicator function, representing the convolution of parameters, characterizing the accuracy of aircraft touchdown to a runway. Parameters of the neural network model are determined as a result of neural network «training» by the data obtained during execution of previous flights. Thus, the suggested model allows predict the accuracy of bringing an aircraft to a runway based on current values characterizing aircraft-pilot system status. The paper gives the results of pilot's control actions model building-up using the data obtained in the course of landing modes execution by two operators working at hardware-software MiG-AT aircraft simulator. Based on the obtained results we can draw the following conclusions. Adaptation of neural network model of a more experienced pilot is achieved only by updating weight factors of neurons with retention of its structure. With a primary pilot who does not demonstrate aircraft handling stable skill, adaptation of neural network model in the course of his professional activity is provided by changing both the neural network model structure and its parameters. Thus, the obtained results allow claim that individual manner of actions of a concrete pilot reveals either in the structure, or in parameters of neural network model, characterizing him. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Maximov N. А., Skleimin Y. B., Sharonov A. V. A model for evaluating the effectiveness of the monitoring system using a group of unmanned aerial vehicles . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 30-39. We can get maximum effect from the use of unmanned aerial vehicles (UAV), if a certain infrastructure, including a group of UAVs, mobile control tools, system of commands and information receiving and transmission, as well as information- processing equipment is formed. The transition from the use of single UAVs to highly organized UAV complexes assumes the availability of advanced supporting and control complexes. Their creation is impossible without preliminary analysis and modeling of the processes of information interoperability of separate systems, included in such complexes. The paper describes a conceptual model of complex monitoring system built by the authors, which uses UAV complex combined with both control systems and systems of information processing and delivery. The object of modeling are information processes, occurring in supporting and control complexes: monitoring data acquisition, its transmission through the channel forming means and processing at various facilities distributed among the transmission path. The goal of modeling: — identification of successful strategies of complexes organization and functioning: — operational feasibility checking of monitoring schedule, processing and connection under conditions of random interferences and hardware failure (or killing effects for military applications); — the possibility of using the model as an instrument for monitoring current system conditions with the use of real data; — the possibility of operational rescheduling caused by unexpected changing of system operating conditions. Statistics obtained as a result of the imitation modeling enables evaluation of different approaches to organization and operation strategy of the system, and obtaining an starting point for more detailed, and hence more laborious optimization, reducing the search for optimal solution set. The developed imitation model allows evaluate the effectiveness of monitoring system at the stage of design, and can be useful for monitoring (shooting) strategies selection. The developed model was tested on a series of hypothetic examples distinct from each other in strategies of UAV use for fulfilling the task of surveying the territory with pin-point targets located on it. The modeling was carried out in the wide range of initial data and revealed operating capacity and non-contradiction of the developed imitation model. Developers of software tools and algorithms for information interaction can be users of the imitation model. Besides them, the described model can be used for distribution of tasks among UAVs belonged to different launch teams. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dolzhikov V. I., Nikolaev A. V. Determination of aerodynamic characteristics of rotating aircraft in the uncontrolled flight by means of engineering analysis systems . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 47-53. In this work the standard software package on ANSYS CFX hydraulic gas dynamics is used for calculation of aerodynamic characteristics (coefficient of front resistance) of the rotating aircraft (A). Currently, mathematical modeling methods are used for the determination of the aerodynamic characteristics for a wide range of aircraft. The main advantage of calculated methods is that once properly developed mathematical model and the program can be used repeatedly in different variants of the aircraft assembly scheme, which provides prompt problem resolution of determining aerodynamic characteristics. This paper considers the simulation of the gas flow around the rotating smooth bodies based on accurate finite-difference method in a computing environment ANSYS CFX. The algorithms for solving the Navier- Stokes equations for the flow space, axisymmetric bodies by viscous gas on the basis of a complete system of equations that allows you to calculate the coefficient of drag of rotating aircraft for different Mach numbers and calculate the change in this ratio for the given angle of attack, which at the stage of setting the geometry of the computational domain is defined by the angular position of rotating aircraft relative to the oncoming flow. Comparison of simulation results with field experiments performed, showed that the convergence in determining the drag coefficient is within the range of 5%. Considered is the question of the influence of the rotational motion of the center of mass on the flight of uncontrolled aircraft. For that purpose, on the basis of the calculated data of drag coefficient of rotating aircraft with angles of attack other than zero method of least squares, allowed obtain the dependence of the ballistic coefficient of the angle of attack. Thus, using the obtained dependence of the ballistic coefficient from the angle of attack it is possible to account the angular perturbations when calculating the parameters of the rotating trajectory aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Usovik I. V., Darnopykh V. V., Malyshev V. V. Methodology of evolution of technogenic pollution assessment of low Earth orbits with regard to mutual collisions and active space debris removal . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 54-62. Space debris (SD) creates more and more problems for the spacecraft operating in low earth orbits (LEO). At present experts worldwide come to the conclusion that there the need to «clean up» near-Earth space environment from space debris becomes urgent. However, now there is no adequate substantiation of active SD removal effectiveness impact on techmogenic pollution evolution. Thus, the efforts concerning the evaluation of active removal of large SD objects effectiveness impact on long-term technogenic pollution of LEO region are carried out within the framework of Inter-Agency Coordination Committee on Space Debris activities. The paper presents the results of the developed methodology as a part of these activities The major element of the methodology is a statistical model of SD developed by A. I. Nazarenko. We suggest to describe the whole set of objects X as a set of objects described by three subsets: D — debris, ADR — the objects that can be subjected to the operation of the active removal, NEW — new launched objects with respect to which we consider technogenic pollution limitation measures. To solve the problems of mutual collisions and impacts of the collisions we shall describe the set X using a statistic SD model and multitudes specified in it. The subsets ADR and NEW will be described additionally using complete information on every object with a single-piece description. Prediction of orbital evolution of objects from the subset D will be carried out using methodologies of statistical model SD, the subsets ADR and NEW with prediction of the orbital parameters of each object. Accounting of active removal and SD limiting measures occurs while deleting objects from the subsets ADR and NEW, and as a consequence from the total set X. Analysis of the results of implementation of the developed methodology showed that for technogenic pollution of LEO region reduction in the longer term at least 5 large objects a year should be removed. However, the impact of the effectiveness of the SD active removal on long-term evolution of SD would be estimated in the decades to come. The obtained results agree well with those of other researchers. We identified the areas in which it is necessary to carry out the operation of the SD active removal in the first place:
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Zharenov I. S., Zhumaev Z. S. Thermal Control Provision System for the TabletSat-Aurora microsatellite: design and flight adaptation. Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 63-75. The paper considers the design of Thermal Control System (TCS) for TabletSat microsatellite. The satellite was launched into orbit (SSO, 606 km altitude, LTAN 10:30) from Yasny space-launch complex on June 19, 2014 for non-commercial technological experiments. The lead product developer of this satellite is JSC SPUTNIX. The satellite, just as the entire TabletSat platform, was designed according to Plug-and-Play principle. It required, apart from interfaces standardization, to use methods of fast thermal control system (TCS) development, which would allow provide proper thermal fields on-board for a wide range of payloads and spacecraft structures. Due to narrow time and development cost constraints the decision to implement passive type of TCS was taken. For fast TCS development the authors recommend to fasten all side panels with standardized brass thermal bridges; connect all instruments and other thermal contact surfaces by heat-conductive adhesive; to install electric heaters with temperature control inside overcooling sensitive devices. TabletSat-Aurora has the shape of a hexagonal prism, consisted of structural panels with onboard systems mounted on them, and deployable solar panels installed on the top panel plane. Panel optical enamel coating scheme is determined from computational modeling with modern CAE systems, such as Thermal Desktop, which the authors of the paper used. Thermal modeling is carried out with allowance for heat currents from the Sun, the Earth and Sun radiation reflected form the Earth. It also considers the cyclic graph of on-board equipment heat emission. For each scheme of panel optical enamel coating the authors carried out time simulation for different spacecraft ADCS modes for 14 orbit passes, which compose full spacecraft operation cycle with payload energy-storage passes. The best TCS structural scheme was sel ected according to the results of modeling. During the satellite flight operation data fr om thermal sensors mounted inside the onboard devices, batteries and solar panels have been collected. The experimental data agreed on the qualitative level with the results of modeling (the ranges of temperature variations obtained by modeling and in reality are the same). The authors determined also the results of future updating of fast TCS development standard for microsatellites, as well as recent trends of TM/TC system upgrade. In accordance with the results of the satellite assembly, suggestions to structural elements update, such as search for optical non-crumpling enamel and replacement of heat-conductive adhesive by conductive gaskets to provide fast disassembling. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ryabov A. A., Romanov V. I., Kukanov S. S., Shmotin Y. N., Gabov D. V. Numerical and experimental criterion of gas turbine engine hull dynamic strength in case of open rotor blade out . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 76-84. The solution of safety issues of gas turbine engines (GTE) for modern and advanced passenger aircrafts in emergency situations is a very important task of improving the reliability of aeronautical engineering. One of the possible and most severe accidents is a fan blade out of a running engine. In this case, the broken blade hits the engine hull at high velocity and may rupture it, which is impermissible. Numerical study of the blade and engine hull collision [1— 8, 11, 12] shows that the process of dynamic deformation takes place under complex stress conditions and characterized by high velocities and strain levels. Thus, we need reliable dynamic strength criterions to validate the engines impact resistance. When the blade hits the engine hull, its body deformation is local. Hence, to develop the dynamic strength criteria, we can examine a collision of rectangular plates, where local deformation is very similar to that of a real engine in terms of a stress state, deformation levels and rates. The aim of this work is to investigate numerically the impact deformation and develop computational and experimental criterions of impact resistance. In this work, we examine the mutual collision of a flying rectangular titanium plate of a constant thickness with a quiescent aluminum target plate of a constant thickness. The target size was sel ected so as to eliminate boundary conditions impact on local deformations. The studies are carried out in velocity ranges V0 ~ 160...239 m/s at different impact angles: φ = 90° (normal impact),φ = 60° and φ = 45°. Experimental studies show that in the case of normal impact, at the impact velocity of V0 = 160,8 m/s, the target is deformed, but not ruptured. At the impact velocity of V0 = 195,0 м/с, the flying plate ruptures the target and gets stuck in it. For the impact angle of φ = = 60°, for two cases of similar impact velocities: V0 = = 199,6 m/s and V0 = 201,3 m/s, the target did not penetrate in the first case and completely penetrated in the second case. At the impact angle of φ = 45° in the range of velocities V0 = 210,8...218,8 m/s the target did not penetrate. The problem of numerical simulation of is formulated in Lagrangian representation, the equation of motion is based on the principle of virtual operation. The equations of state are recorded in the form of the flow theory with kinematic and isotropic hardening. The mutual collision of the plates is investigated numerically by solving a non-stationary contact problem with variable boundaries. Numerical simulation is based on the finite element method and explicit time integration scheme, implemented in LS-DYNA [9]. The results of numerical simulations and their comparison to the experimental data show that the duration of the active deformation processes equals ta = 50...150 µs for all cases of loading V0 = 160...239 m/s in the range of angles φ = 45°...90°. Maximum deformation rates develop at the impact side and reach ε = (5...7) 103 с-1. During the mutual collision, in all cases the stress state close to triaxial compression П ~ —1,0 [10]) at the target impact side occurs, with biaxial extension П ~ +0,80 [10]) on the opposiste side. The flying plate kinetic energy is not the criterion of target rupturing. With equal or similar kinetic energy of the hitting plate, the target destruction is largely determined by the conditions of the initial contact interaction («perimeter», «line», «point») that affecting the localization of the target deformations. In all considered cases the target destruction starts fr om the impact side and is characterized by the local shear (cut) in the contact zone of the plate and the target. The deformation intensity stands for the measure of this shear and can be considered as the dynamic strength criterion. For the considered material, we determine the design and experimental criterion of dynamic strength as εi= 24...25%. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mesnyankin S. Y. On the selection of optimal values for the thermal contact of structural components of aircraft engines. Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 85-90. This paper deals with the problems related to the determination of the temperature state of contacting elements of aircraft engines, when contact thermal resistance occurs due to the imperfections of the mechanical coupling due to the discrete nature of the contact. It also considers physical aspects of the contact heat exchange and analyzes three components of thermal energy transfer. The known analytical equations describing contacting in the air were analyzed in detail. The conclusion was drawn that the known dependences cannot be universal for practical problems, though the difference between the calculated values and the experimental data due to the uncertainty of numerous empirical coefficients and conditions of generalizing dependencies is essential. This statement is supported by the calculations with respect to the contact pair of stainless steel in a wide range of thermal and mechanical stress, which further allowed us to estimate additionally the contribution of different components of point contacts thermal resistance and environment. Taking into consideration the revealed discrepancies and for the purpose of a more rigorous recordkeeping of temperature losses in the contact zone, the author suggests a fundamentally new generalized equation, which derivation is based on the classic analysis of the contact conductance components. Describing successively the share of each value of the total thermal resistance in dimensionless form and justifying the influence of each of the values the author proposed the structural formula. The empirical coefficients of this formula are obtained by statistical processing of the well-known experiments. The results of summarizing are shown in the form of a graphic dependence of the contacting materials and their surface finishing. According to the results of generalization a conclusion about a successful correlation of experimental and calculated data is made. The reasons of the marked differences are analyzed as well. The results of the work with great certainty and precision allow us to determine the values of the thermal contact resistance between materials of special interest and to select their optimal values. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zinenkov Y. V., Lukovnikov A. V., Cherkasov A. N. Estimation of the effectiveness of a power plant for a high-altitude unmanned aerial vehicle . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 91-102. The task of development of a modern domestic unmanned aerial vehicle (UAV) with a cruising altitude of 18-20 km and characteristics equal to the best foreign prototypes is very important. The requirements relating to such type of UAVs are still not determined not only to the aircraft complex as a whole, but also to its individual systems, and power plant (PP) in particular. Thus, a wide range of urgent issues arise in this area requiring research and working out, including the design of engines of new generation for PP of such kind of UAV. The authors suggest in this respect a methodology of forming a PP preliminary technical appearance for a high-altitude UAV. It will allow selection and substantiation of rational parameters of the operating procedure, controlling program, scheme of gas turbine engine (GTE) of straight reaction, as well as characteristics of the PP inlet and outlet devices, guaranteeing the achievement of the extreme (best) values of the UAV performance factors. The key core of this methodology is the integrated mathematical model (IMM) of the technical system Unmanned aircraft — power plant, developed by the authors. This IMM is intended for carrying out various exploratory parametric and optimization studies on the formation of technical characteristics of various schemes of turbojet engines, as well as evaluate PP internal parameters effectiveness and UAV performance criteria, such as, its performance characteristics. The authors carried out the assessment of adequacy and accuracy of the developed IMM of the UAV-PP system by the example, using a number of existing engines and aircrafts. As a result it was concluded that this IMM is accurate enough for conducting various engineering studies concerning the formation of a preliminary technical aspect of the aircraft GTEs of straight reaction. Using the IMM we conducted a series of parametric studies of PP with bypass turbojet engine parameters impact on its characteristics and UAV characterixtics This work formulates and solves optimization problem, consisted in the best PP technical aspect selection by the performance criteria of the UAV — maximum range and duration of the flight. As a result, we obtained Pareto set of optimal solutions, from which a compromise variant of UAV-PP system, ensuring the improvement of aircraft performance characteristics as compared to a certain basic (non-optimal) variant by flight range of 10.4%, and duration of 9.3 % was obtained. The practical value of this work consist of the following. Its results can be used by scientific and engineering organizations, engaged in the design of perspective UAVs and their PPs, as well as by the air force and in industry for validation of the requirements to new patterns of aeronautical engineering, as well as by aircraft engineering institutes to improve the educational process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grigoriev V. A., Zagrebelnyi A. O., Kuznetsov S. P. On the of power plant mass evaluation in the problem of aircraft turboprop operating procedure optimization . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 103-106. This paper considers the role and place of mathematical model of a turboprop engine power plant mass generation in the problem of gas turbine engine operating procedure optimization at the stage of initial design. The mass of a power plant with turboprop is one of the major components, actually defining parameters matching of an aircraft and its engine, in the course of forming a takeoff weight of an aircraft, which indirectly defines the costs of material resources to create an entire aircraft designed system. Moreover, in the performance of parametric studies the project weight of a power plant should be estimate by turboprop parameters. However, such dependencies hitherto are underresearched. Thus, the evaluation of the engine weight dependencies on its operating procedure parameters is carried out based on either integrated data on generalized statistics on completed designs, or on weight parametric models, as far as more precise information is not available at this stage. We compared a number of state-of-the-art approaches to evaluation of the mass of a power plant at the initial design stage. We proposed also several variants of power plant mass models, differing from each other by the number of parameters required for calculation at the initial design stage and accuracy of the models themselves. A comparative analysis of mathematical models reveals their advantages and disadvantages for different stages of the design. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okorokova N. S., Perchenok A. V., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. Power Plant for vehicle of astronauts autonomous movement. Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 107-115. The paper presents designing computation and defines specific energy-mass characteristics of a new type of power plants (PP) for off-line power supply of an astronaut in space, based on oxygen-aluminum O2/Al chemical current source (CCS). Such PP with 100 W rated power of 27 ± 3 VDC and short-term current change from 0.45A to 35A should provide necessary energy storage for active operation during 180 hours (30 six-hour cycles) with long-lasting pauses, as well as storage capability within a year before setting to operation. The authors developed structural diagrams for 1, 5 and 15 six-hour cycles. The simplest PP structure and operation mode demonstrates the PP meant for one- cycle. It almost fully autonomous in relation to on-board systems and highly reliable. However, to support the entire program we will need to install 30 PPs of such kind on-board a spacecraft. After mission completion such kind of PP either recycled, or returned to Earth for recharging. PP designed for five operation cycles with prolonged pauses has more complicated structural diagram. After operation cycle completion, this PP is connected to conservation system, and should be refueled with Oxygen before the next start-up. However, only six of such PPs are necessary on-board the spacecraft, instead of 30 pieces of the previous kind. The structural diagram of O2/A1 PP for 15 operation cycles is most complicated, since it includes addition electrolyte adjusting systems, as well as its solid resultant (aluminum hydroxide Al(OH)3) purification, and consumed water supplying. Comparative mass calculations were performed for all PP variants. We choose the minimum PP mass as an optimization criterion, and the value of current density in O2/A1 elements as a variable parameter. Calculations were performed on experimental data obtained with the O2/Al CCS laboratory sample with aluminum anode, made of Aluminum-Indium alloy (A995 + 0.6 wt.% In In0), in alkaline electrolyte based on 4M NaOH with addition of 0,06M sodium stannate Na2SnO3, that inhibits aluminum corrosion. As the calculations showed, the installation designed for one-cycle operation has the minimum weight. However, the PP designed for 15-cycle operation exhibits minimum total weight and best specific characteristics. It was shown for the first time that hydronic CCS with aluminum anode may also be used in space as the hydrogen generator for the hydrogen-oxygen (O2/H2) fuel cell (FC) in the combined PP (CPP). It solves effectively and safely the problem of prolonged storage of hydrogen for autonomous PPs based on O2/H2 FC. Energy characteristics of such CPP exceed those of PP consisted of only of O2/H2FC. When put into practice such CPP will be able to satisfy the requirements on long pauses between runs and may be considered as an autonomous energy supply for an astronaut. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zadorina E. N. Predictive capability studies of relaxation nature of thermal degradation of polymers . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 116-121. The author first proposed to consider the process of thermal degradation of polymers as a kind of process of physical-chemical relaxation. The process has two components: chemical, due to the rupture of chemical bonds and physical, associated with the movement of the structural units of the polymer. In this case, the so-called apparent or effective, kinetic characteristics of the process — the pre-exponential factor, activation energy and reaction order — purchase a specific physical meaning. Easy to overcome the energy barrier of a chemical reaction is preceded by the movement of the respective nanostructured polymer units, that is ongoing in parallel with other processes, with nature and relaxation which also requires a certain energy. Calculation of kinetic parameters is important not only for the formal description of the process, but also to obtain data on the structure of the polymer. For this purpose it was proposed to consider the process of thermal degradation of the PM as kinetic plane described by the three parameters. Defining segments, that the kinetic plane trims on the coordinate axes X, Y, Z, and the angles formed, it is possible to calculate the kinetic parameters of thermal degradation process of the polymer. The author introduced the concept of the relaxation time of thermal degradation of the polymer τр. Asked to count it as a time of transition of the polymer fr om the initial equilibrium state to equilibrium state corresponding to the high-temperature heating conditions: ( Tf—Ti)/b wh ere Ti and Tf is the temperature of the beginning and end of the thermal degradation process, b is the heating rate, K/s. This approach allows us reliably interpret experimental results and to predict the thermal behavior of polymeric materials at high speeds heating. Specialists receive information, allowing the use of nanotechnology for targeted development of the nanostructure of polymer materials heatproof destination. On the other hand, the creation of nanostructured polymers and polymer composites is achieved processes of thermodestruction management. Of special interest, relaxational nature of thermal degradation of polymers should cause researchers stress-strain states of polymeric composite materials, working in conditions of high temperature heating and used to create structural elements of modern aerospace. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sen'kov A. P., Bormotov A. V., Sedunov D. Y. Winding coefficient and rotor losses in servo motors with stator tooth concentrated windings . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 122-131. The article describes methods of winding ratio determining in AC electric motors with tooth stator coils and permanent magnets rotor, and presents the values for several design styles of such motors. On the example of the three-phase two-piece electric motor with radial flux, 18 teeth of the stator and 10 rotor poles, an analytical expression of the winding ratio was obtained (from the slot e. m. f. first harmonics vector diagram and the instantaneous rotor position). Additionally, alternative analytical method for determining the winding ratio is shown (based on the known expressions for the motors with distributed two- layer stator winding with adaptation to the tooth winding motors). As the result of this calculation it we concluded that the value of the winding factor increases with the number of coils in the coil phase group. The paper presents a comparative analysis of the electric motors of distributed and tooth stator windings design, highlights a number of positive features of tooth windings motors. We made a hypothesis on eddy currents origin in rotor elements due to the presence of pulsating electromagnetic stator flux. Distribution nature and eddy current losses value that occur in the rotor and its elements (for three different speeds) are shown with the motor model in Ansys Maxwell v.16. package finite element analysis. As one of electric motor efficiency factors, the value of winding coefficient (obtained for a particular number combination of the rotor pole pairs and stator teeth) allowed choose the most efficient motor in electromechanical actuator design stage. Knowledge of eddy current value and distribution nature in the rotor design elements allowed take measures, leading to these losses reducion. The article is prepared in accordance with R&D work High-tech production creation of precision high- speed enforced electromechanical actuators of the new generation at ITMO Univercity, with financial support from Russian Federation Ministry of Education and Science. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhikharev D. Y., Kirillov V. Y. Modeling of electromagnetic environment as a radiated field in the internal spacecraft structures. Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 132-138. Modeling of the electromagnetic environment is a promising direction of designing the systems on board the spacecraft. Modeling electromagnetic environment allows you to define the levels of radiated electromagnetic interference in different parts of the spacecraft structure and draw conclusions on the need to improve on-board equipment and changing ways of laying cables. The paper presents a method of electromagnetic environment modeling of systems on board the spacecraft. The method consists in replacing the real on- board devices, emitting electromagnetic interference (EMI), by equivalent sources. The advantage of the method is that it allows recreate electromagnetic environment created by on-board devices and a small number of experimental measurements. Studies of real samples of on-board devices can significantly improve modeling accuracy of electromagnetic environment due to the individual features of electromagnetic interference in electrical circuits of each of the devices. This method allows model electromagnetic environment according to geometric dimensions and arrangement of devices anywhere in the spacecraft. The paper gives examples of modeling of on-board instruments on the basis of the proposed method. As imitators corps on-board devices used metal construction of a cubic structure with attached generators. Initially, the electric field strength is measured using an antenna, then calculates the values of the field theoretical method. The modeling results are presented in the form of the spatial distribution of the electric field. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov S. B., Averin S. V., Kharchenko I. A., Tret'yak V. I., Konyakhin S. F. Multiphase pulse transducer for aircraft anti-ice vibrator feeding . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 139-145. New circuit approach to aircraft on-board and airfield electro-pulse anti-ice systems with high reliability, electric power efficiency, assembly processability as well as electromagnetic compatibility is examined. Anti-ice systems represent a key facility for flight security and aircraft installations normal operation. They play an important part providing successful operation of following. They provide successful operation of the following on-board & ground-based equipment: air-field radar, light signal, high voltage, wind-driven, antenna feeder, gas-piping and etc. (especially for facilities that are operated out-door under winter conditions or in the north regions). Electro-pulse anti-ice system (EP AIS) represents a certain variety of mechanical anti-ice setup. It provides repetitive pulse impacts in a protected cover. At present the electro-pulse anti-ice systems based on remote contactless impact on the cover is used in aeronautics. They induce pulse eddy currents by means of dedicated EM inductors. These eddy currents induced in certain cover surface areas interact with magnetic field of the latter and produce the pulse vibrations of the cover, and, split off of an ice layer. The debris carried away by the air stream. The main EP AIS advantage is its low power consumption — ten and even hundred times less than other systems energy consumption. The general shortcomings of such systems are as follows: low system assembly processability due to bulk inductors for various parts of the cover (their area of action is limited by surface junctions and device reinforcing elements), residual ice formation under relatively large exposed area; the necessity of pulse power boost in case of higher rigidity of construction; structural complexity and its low reliability for composites. There is a reasonable way to reject the induction vortex interaction between vibrator inductor coil and the cover: the usage of the pair of cores — fixid and movable one. The latter is fixed on the spring and is supplied with a percussion lug for knocking the cover (including materials with low electro-conductivity -composite via metallic substitutes). The power stage of the secondary pulse power source for anti-ice vibrators with primary supply from low- voltage DC mains network (27 V) is presented in this article. The circuit represents a reversible (bidirectional) step-down / step-up pulse converter with reactor integrator and a damper-snabber non-dissipating circuit for modulator switch «soft» commutation. The power taken from the power source is relatively small due to energy batch recuperation from reactor integrator back to power source and to input C- integrator as well as due to commutation loss reduction by soft key switching. In addition the switch commutatin overstress and inversely-diode overcurrent are eliminated. Moreover, the HF commutation noise emission is also reduced. The new circuit solution examined in this article is intended for on-board and airfield electro-pulse anti- ice system design. It provides the equipment functional capabilities enhancement due to bidirectional energy conversion, particularly its recuperation, as well as efficiency and reliability enhancement, EM compatibility improvement thanks to switching overstress and inversely-diode overcurrent elimination as well as switching heat loss The presented circuit solution is protected by Russian Federation priority. The research presents interest for a wide circle of specialists in the field of aircraft electrical equipment design as well as anti-ice equipment for ships and stationary installations, used for instance in airfield radar and lighting equipment in the north. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tihonov A. I. Model of complex realization of the concept of import substitution in innovative environment (by the example of aviation engine building). Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 146-153. The paper is devoted to the issues of implementation of the concept of accelerated import substitution by the example of aircraft engine building. Despite the fact that Russia has created a powerful industrial and scientific potential, it does not provide the proper competitiveness of aircraft industry. The situation is near critical since the civil aviation market is lost. For the most part, indexes of effectiveness of home-produced aircraft engines should be adjusted to international standards. It is proved that high efficiency of import substitution of this industry sector can be achieved only using complex approach, based on real and rationally organized integration of science and industry, when manufacturer works in interactive mode with scientific departments and organizations in the course of design of new samples. It also requires upgrade of integrated vertical structure on the principle of cyclical turnaround and horizontal links; provision of in-home cooperation effectiveness; innovation projects and programs, methods and technologies; comprehensive planning and marketing management; high quality and ecological properties assurance; building up unified virtual environment of design and engineering analysis; support of pilot and mass production, after-sale services, inter-industry integration. The goal of the state policy of import substitution in this situation means creation of favorable conditions for the coordinated development of the multi-project environment, which will reduce or neutralize the risk of uncertainty growth and take into account various effects. Russia is the one of only five countries that can independently develop and produce aircraft engines. Since 2008 Russian airlines have acquired nearly 600 foreign aircraft, and only 59 produced in Russia, while the share of modern Russian aircraft account for about 7% of the total fleet of Russia, and their contribution to total passenger traffic volume is only 4%. Intolerable situation in the park of medium-haul aircraft, where the share of foreign aircraft is about 80%, i. e. it is about the Reconquista own market. In the production of short- haul passenger aircraft SSJ-100 the share of imported suppliers is about 60%. Now you need to bet on the innovation and quality of the engines. Thus, the main directions of improving the competitiveness of the industry include:
In order to improve flight performance the most problematic issue for domestic aircraft engines is achieving optimal values of the following indicators:
The main directions of implementation of programs aimed at costs reduction are as follows: minimization of losses; outsourcing of services; productivity increase:
The substitution in aircraft engine, as a strategically important field, can be effectively achieved only as a result of sound economic policies, creation of the next generation of products based on complex approach, which provides a logical linking of the trajectories of development for individual enterprises producing aircraft engines and other aviation equipment and related industries and activities. The fast import substitution strategy should be considered as a set of concurrently running projects focused on competitive domestic and foreign markets, for which it is necessary to create favorable conditions for the coordinated development of the multi-project environment. Accelerated substitution is a public task, which is possible only under condition of use of the integrated approach, where special attention should be paid to financial support in order to establish scientific and technological basis for critical technologies, components and systems for advanced engines and increase their advanced pilot producing during the stage of research. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kobzar A. I., Tikmenov V. N., Tikmenova I. V. Methods of Games theory in problems of optimal production planning . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 154-160. Uncertain demand for output products forces a manufacturer to make planned decisions under conditions of uncertainty and risk. An efficient tool for enhancing the quality of planned solutions is implementation of the games theory methods. The article analyses the task of searching for an optimal decision in a situation, where the volume of government-guaranteed orders is a source of uncertainty and risk. A search for optimal decisions comes down to the game with nature, in which one player — companys management — acts consciously and the second player — nature (state customer) — makes decisions regardless of the companys management and is guided only by changing of external economic and political conditions. The article considers also methodological issues related to making a decision on optimization of a Government order performance plan by the example of a defense industry enterprise. The article describes the key elements of payoff matrix related to the game with nature. The companys profit maximization is a criterion of optimal planning decision. The maximax criteria advanced by Wald, Hurwitz and Savage under conditions of uncertainty is applied. Applying an expert probability estimate of the state of nature (a volume of government orders) makes it possible to calculate the risk criteria by Bayes, Laplace, Hodges-Lehmann. The opinion consistency within a group of experts is estimated by Kendalls and Babington Smiths coefficient of concordance. A comprehensive comparison of total calculated criteria allowed developing an optimal strategy for preparation of government order performance plan ensuring the companys maximum average profit provided that it is fulfilled within the established time limits. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kiseleva G. S. Integrated assessment of the in-house stuff training effectiveness at a production enterprise . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 161-167. The goal of development and implementation of the assessment of in-house staff training effectiveness of a production enterprise is the increase of the return on the stuff of an organization education investment by assessing and identifying resources to improve the socio-economic benefits of training, retraining and skills development. Design/methodology/approach To create this methodology the author developed a classification of approaches to efficiency upgrading of training, retraining and professional development of the stuff: investment, psychological and competency, institutional. As far as the assessment of the result should contain economic and social aspects, which results are internally interdependent, economic outcome is socially significant, and achievement of economic performances creates objective possibilities for more complete satisfaction of material and moral needs. Conclusions Implementation of the methodology for assessing the effectiveness of training at production enterprise will reduce not only time, but also the financial resources of the organization. In general, professional development plays an important role, since in the course of the learning process the worker acquires a new theoretical knowledge required for the implementation of labor activity. It increases the ability of the personnel to adapt to changing economic and working conditions as well. Practical recommendations The methodology of assessment of the in-house stuff training efficiency at a machine-building enterprise is developed, differentiated depending on the purpose of assessment. It consists of: 1) effectiveness assessment by stuff levels — a separate employee, department, organization; 2) effectiveness assessment by stuff categories: workers, specialists, executives; 3) determination of economic, social effectiveness, the degree of meeting a set goal objective. Originality / value The methodological approaches for improvement of in-house training and evaluation proposed by the author can improve its effectiveness. Investment, psychological, institutional and competence approaches contribute to the optimal planning and content of the educational process, determining the effectiveness of training and identifying the main factors affecting the in-house training in general. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tsybulevskii S. E. Using forming factor of new corporate layout of space-rocket industry in variation of searching for sources of domestic investment of space industry enterprises. Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 168-171. Subject area of the case Business economics of aerospace industry enterprises. Method The studies carried out on the analysis of the current phase of the space industry reform bear generalized popular- science character. The article analyzes the preliminary results of the corporate activities of rocket and space industry enterprises in 2013 and provides suggestions for optimizing and building effective corporate governance, considering among them the possibilities of expenditures minimization in its practical incorporation. Results Information obtained in the course of preliminary work as well as carried out analysis of statistical data indicate that ongoing works on reforming the space-rocket industry with regard to structural transformations need some adjustment for the purpose of forming mechanisms of personified responsibility for taken decisions and final actual result. Practical implications One can use the results of the study to build an effective system of corporate governance in the existing integrated space-rocket industry structures, as well as to search for new sources of domestic investment space-rocket companies included in these associations. Conclusions Currently, it is possible and necessary to use the existing potential of the Federal Law of 26.12.1995 № 208-FZ On Joint-Stock Companies for the optimization of internal corporate communications in order to find sources of domestic investment companies of aerospace industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panagushin V. P., Chaika N. K. Restructuring of airlines based of their division into business units and allocation of industrial park at vacant production areas . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 172-180. The article discusses the methodology of restructuring the aircraft manufacturing enterprises based on their division into business units and allocation of industrial park at vacant production areas. The authors identified three groups of methods of manufacturing assets of aviation enterprises restructuring, and suggested the ways of carrying out the restructuring of aircraft manufacturing enterprises production assets according to the selected groups. The article presents the performed analysis of the reasons for the unprofitability of the enterprises of aviation industry and determines the groups of factors, which cause it: design-engineering, economic, financial, in-house governance. To eliminate the causes of unprofitability we suggest a package of measures concerning utilization of free production facilities. The basic measure is the restructuring of production assets based on the integration of the plant and industrial park. For restructuring of production assets of enterprises of the aviation industry we considered normative and legislative acts making provision for such restructuring. We considered the following concepts:, technological park, technological park in the sphere of high technologies, industrial park, business park, technopolis, cluster (technology area), and revealed the differences between these structures. Examples of creation of technological park at the aircraft-building enterprises are given. Such concepts as anchor and invited residents are introduced. We suggest a technological park management structure based on financial accounting centers (FAC), and allocation of functions between FAC and technological park executive heads. We outlined as well the functions of the treasury (accounting and finance center), and showed the ways for increasing the profitability of a profit-center. We assigned to such methods: cost saving, functional and cost analysis of the products to the effect of cost reduction and increase of income and bonus. The article suggests allocation of functions between FAC and avionic technological park executive heads, and highlights these functions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mikhailova E. A., Krylov S. V. Purposes and methods of research and development cost management at the aircraft engine-building enterprises . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 181-189. The article considers the main requirements to a research and development cost management system at the aircraft engine-building companies. These requirements are claimed both in terms of research and development features as an activity category, and relative to the aircraft-engine-building branch peculiarities stipulated by specifics of life cycle of gas-turbine engines. We determined the main limitations imposed on the research and development cost management system with a view to the necessity to carry out the existing norms of active legislation, implemented to ensure State defense order. Based on an information available in free access the paper gives the examples of practical suppositions of the necessity of research and development cost management at aircraft engine-building enterprise JSC NPO Saturn. The paper considers the classification of cost management methods according to organizational and administrative level of applied approaches. Based on the considered requirements and limitations we suggest recommendations on development, organization and selection of trends of development of research and development cost management system at an aircraft engine-building company. The research and development cost management system should provide sustained management in conditions of:
Cost research and development management at the aircraft-engine-building companies should be carried out by the integrated subsystem of business management providing rational distribution of resources between existing projects according to the purposes of the organization, and representing generally system of norms and the rules supported by mechanism of their execution. One of the variants of classification of cost management methods is the group of cost management methods depending on organizational and administrative level on which administering is exercised. By following this classification, it is possible to split cost management methods into three main groups: operational methods, managerial methods and strategic methods. Examples of popular cost management methods are target costing and earned value analysis. These methods are widely used in the sphere of management of research and development and in project management. It is worth noting that only reasonable application of various methods of cost management at operational, managerial and strategic levels will allow minimize disadvantages of applied approaches, and achieve synergetic effect from a combination of their advantages. Methods of target costing and earned value analysis considered in the present article are widespread methods of cost management at the enterprises and have considerable theoretical and practical base of use. Nevertheless, their full integration into an enterprise management system is still involves considerable difficulties and related to resistance, both from managers, and from the staff. Increase of efficiency of use of methods of target costing and earned value analysis is obviously possible by organic integration of these methods into the intra- corporate institutes providing comprehensive support of adoption of administrative decisions at all administrative levels. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilochkina N. G., Ryapukhin A. V., Cherner N. V. Organizing mechanism of risk controlling of the productive processes at aircraft engine-building enterprises . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 190-196. The article presents the executive summary of risk controlling of the continuity of productive processes and mechanism as applied to the enterprises of the aircraft engine industry. Creation of world-class corporations in the key segments of aviation industry requires, among other things, design of aircraft engines that meet international standards and allows a successful entrance to the global market of domestic corporate formations in the aircraft industry, as major players for long-term perspective. The necessary condition for stable functioning and development of aircraft engine-building enterprises is their ability to detect and prevent in time negative consequences that can jeopardize the very existence of the enterprise. In aircraft engine-building industry, as in many other branches of Russias military industrial complex, the necessity for radical restructuring of the enterprise management system is urgent, and under conditions of uncertainty in particular. We need to introduce new tools of enterprise management by which the continuity of production is provided. One of the tools responsible for ensuring the stability and survival of an enterprise is the continuity of the production processes risk controlling. Analysis of the research in the field of management, productive processes continuity at the enterprises of machine-building industry both in Russia and abroad has allowed development of conceptual basics of the productive processes continuity risk controlling for enterprises of the aircraft engine-building. The article presents the structured analysis of the existing standards for continuity of production activities allowing develop the principles of the productive processes continuity risk controlling. We classified and substantiateв the data acquired in the course of the study. It allowed developing scientific methodological issues of developing productive processes continuity risk controlling system for aircraft engine- building enterprises. Based on productive methodology of activity continuity control we developed and tested the mechanism of production continuity risk control at JSC Kuznetsov. Risk controlling is not yet widely used at Russian machine-building enterprises. The scientific research in this field is also staying at the state of growth. Moreover, it does not exhibit systematic approach to the development of productive activities continuity risk controlling. Thus, it is advisable to bring about risk controlling to manufacturing control, using foreign and domestic experience of advanced corporations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korovin A. V. Methodology of estimation of the required financing schedule of the State defense order . Aerospace MAI Journal, 2015, vol. 22, no 3, pp. 197-200. At present, there is an urgent need to re-equip and rearm of the Armed Forces of Russian Federation (Russian Armed Forces). Scheduling and control of the state defense order (SDO) are important and of government priorities. Formation of requests in the state defense order is a complex and multi-task issue. Its results affect the great number of people, many areas of military service and combat readiness of the Army as a whole. As practice shows, not sufficient time is allowed for the formation of the proposals for the SDO. Moreover, due to lack of personnel and time, SDO is often planned based on the current situation, focusing on the SDOs of previous years, either by leaving the last years numbers, or increasing them by a certain factor. Without automation of the process of the needs of the troops estimating for a specific planning period, the formation of the SDO is superficial and does not reflect the true state of affairs that is unacceptable in such animportant task as the defense of the country. To automate the process of developing the plan, the state defense order for a certain planning period was scheduled using the following technique. A method of short-term forecasting was sel ected and Excel was used as a simulation tool. The source data includes information on certain types of troops supply with weapons and military equipment in a given year. It is based on the reports fr om the troops. According to the results of calculations it is possible to build charts and diagrams, representing in a convenient visual form various development strategies, state technical means at a particular level of funding, which allows you to adjust the financing of the state defense order and specific technical systems. With a minimum set of hardware and software it allows you predict the development, procurement and repair of technical equipment and weapons for the desired period of implementation of the state defense order with quick and accessible representation of the obtained results to the interested military authorities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shved Y. V. Basic geometrical parameters of paraglider wing selection criterion. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 7-14. The article considers wing design parameters, having the greatest impact on its inductive drag. It becomes up- to-date due to the fact, that with low speed flying vehicles, and paragliders among them, inductive component of a sing drag appears to be several times greater than its airfoil part component. From Expressions obtained show that with flying vehicle specified mass and its vertical overload the value of inductive drag of its wing will be inversely proportional to the square of its wingspan and square of its speed. Thus, with equal wingspan and speed, either narrow wing with high aspect ratio and high-lift airfoil, or wide wing with low aspect ratio and low-lift airfoil having equal lifting force will possess the same inductive drag. This implies also the futility of replacement of wide wing by several wings with a number of narrow chordes. Even without considering polyplane wings negative interaction with total area equal to paraglider wing area and wingspan, polyplane wing inductive drag will not be less than that for a monoplane. It is shown for gliding systems, how we can determine required Cya by Cxa and gliding speed, or find gliding speed by aerodynamic coefficients in terms of gliding system characteristics. In both cases we can calculate glide angle and corresponding to it system aerodynamic efficiency in terms of wing parameters; and then locate it relative to shroud lines in such a way that provide required wing incidence angle during gliding. Any two airfoils having the same Kmax, create the same drag at a given lifting force, but the airfoil of the same quality with greater lifting force will require smaller wing chord and, accordingly, greater aspect ratio and minor stiffness with one and the same wing inductive drag. Besides, taking into account that extra lifting force value under lift devices deviation is proportional to wing area, we are interested at maximally wide chord. Thus, airfoils, providing minimum Cya with the same aerodynamic efficiency, are preferable. It is worth mentioning, that the demand for atlas of special airfoils for soft wings in the frame of aerodynamic quality, load-bearing capacity in deformed state, as well as safety, still remains impelling and unsatisfied. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlenko N. S. Parameterization and methods to ensure durability of bearingless main rotors (including rigid rotors) . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 25-35. Parameterization algorithms for main structural elements of helicopter BMR, i. e. bearingless main rotor, (including rigid rotors) is a multiphase task. The first stage involves the static calculations and construction of blade resonance diagram. The calculations of alternative stresses is the content of the second phase of the parameterization. The calculations of the local strength and stiffness is the final phase of calculations based on finite-elements model. This article is devoted to the first stage of BMR parameters selection algorithm and BMR durability analysis. Its main results are also used at subsequent stages of calculations and design. The first stage contains calculations of rotor hub stiffness matrix, blade free vibration modes and frequencies, construction of blade resonance diagram, blade deformation calculations and constant stresses caused by centrifugal force impact during the flight, and blade droop caused by gravity when the helicopter is on the ground. To provide static strength, stability (self-oscillations of flutter type) and dynamic strength of bearingless main rotors its essential to use more complicated calculation models and methods than those used for conventional hinged rotors, due to the complexity of the boundary conditions, used to solve differential equations of natural and forced oscillations of a blade. The paper proposes the solution of this problem by introducing hub stiffness matrix to analytic model, and offers the methodology of its elements calculation. The article describes the design variant of light helicopter bearingless main rotor and presents the results of of BMR rotorhead main parameters selection, which can be generalized for a wide range of designs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komissarenko A. I. Analytical determination of missile angle position taking into account the flexible oscillations. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 36-41. Sometimes interaction of elastic transverse vibrations of the body with an incoming air flow is referred to as aeroelastic vibrations. The frequency of these vibrations typically is close to the body proper vibrations. The vibrations induce unwanted transverse inertial loads on the body, particularly when they reach high amplitudes. In the case when the missile is represented as a perfectly solid bit or when it has a rigid body, only the small perturbations of the motion parameters are considered. It allows to obtain with regard to perturbations a linear system of differential equations with coefficients that depend on parameters of the unperturbed motion. Small thrust vectors induced by transverse vibrations of the body with accurate within the second order of smallness result in no variations of the missile acceleration in longitudinal direction. This acceleration remains the same one as for the nonperturbed motion both in value and in direction. This is the reason why under the small perturbations the transverse motion can be considered regardless of the longitudinal motion. Within a short period of time the guided missile trajectory can be considered as a plain curve, which is little different from a straight line. Therefore, let us consider the nonperturbed motion of the missile within a short period of time as the straight-line motion. The issues of influence of flexible oscillations on flying ballistic and strength characteristics are arising during the process of designing missiles with bigger lengthening. Flexible oscillations occur from the engine tractive force and aerodynamical forces. In this article the missile is substituted for inhomogeneous pivot for the purpose of studying the flexible oscillations. Consideration of missile as inhomogeneous pivot significantly simplifies the study of angle characteristics determination. The differential equations of the missile motion with regard for flexible oscillation have been derived. The differential equations of the missile motion include torque and forces of the generalized coordinates of transverse vibrations are first sounded. In the presented work such characteristics as a tractive, ballistic, weight, aerodynamical and inertial one are substituted for average ones during missile operation. First tone flexible oscillations are taken into account. Analytical dependencies of slip angle change, speed vector change, missile longitudinal axis angle with regard for the flexible oscillations have been obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlov D. V., Petrov D. S. Use of three-stage decomposition method for simulation of spacecraft thermal control subsystem . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 42-54. The article is devoted to simulation of a spacecraft thermal control system with the use of new simulation paradigm. The paradigm is based on three-stage decomposition method, which has been proposed by the authors. The thermal control system under consideration follows the same principles as the on-board systems of real spacecraft like Soyuz TMA-M and Progress-M. At the first stage the hierarchical decomposition is made according to the spacecraft dividing circuit. As a result, the system is divided into parts, which models are named components. Components are nested into each other and establish a hierarchy similar to the dividing circuit. At the second stage the interface decomposition is made when interface entities are picked out in every component prototype. Models of such entities are named simple models (SM). At the third stage the interactional decomposition is made when each SM prototype is considered as a member of various physical interactions. Each SM is composed of set of fragments that represent the SM prototype involvement in interaction of specific physical domain. Each fragment is an object that contains the SM prototype parameters related to the physical domain. Additionally, the number of subroutines is assigned to each fragment that calculates relations between the parameters. While modeling the various links between parameters of different fragments of the same SM are taken into account. That links are named cross-fragment links and implemented with particular subroutines each of which corresponds to the unique fragments combination. Simulation model structure is defined with particular objects bonds. Each bond joins two SMs. Bonds declare copying of parameters between fragments of linked SMs. In this paper the creation of universal standard elements library is considered. The library includes, firstly, the fragment classes definition, which are used for simulation of fluid flow through spacecraft subsystem pipelines, secondly, subroutines for simulation of relationship between heat and hydrodynamic domains, thirdly, bond definition, and, finally, the description of component classes used for spacecraft thermal control subsystem simulation. The main feature of the library is a wide use of cross- fragment links that makes the flexibility of designed fragments possible. For instance, any pipeline for gas flow including heat transfer as well as for liquid isothermal flow is simulated with the use of the same fragments that define pipeline geometric properties. The flow of particular substances is simulated using, firstly, special fragments that define substance properties and, secondly, cross-fragment links between fragments of hydrodynamic, thermal and substantial physical domains. By means of this library the simulation model of a spacecraft thermal control system was designed. The results of the typical processes of simulation have been obtained; the conclusion about the correspondence of the calculations results to the real spaceship telemetry data has been made. The library can be used for simulation of real spacecraft thermal control system with a similar design and operating principle. The library may also be expanded for simulation of various flow processes of different substances of various states, what allows to simulate another spacecraft onboard subsystems like life support system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pechenin V. A., Bolotov M. A. Analysis model and classification of the geometry of gas turbine engine blades . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 55-65. The quality of aircraft engines (specific consumption, gas-dynamic stability, reliability, service life) is embedded in the course of the design process, fixed outat the stage of finalization, providedin the course of production, and implemented during operation. Account for actual geometry of the partsduring design process, and forming the best for current manufacturing environment conditions geometry of the products during manufacturing and assembling is one of the reserves allowing aircraft engine quality increase. Realization of the above mentioned reserve becomes possible with implementation of intellectual system of aircraft engines quality provision. The article presents the technique for the intellectual system of aircraft engines quality provision forming. It shows the structure of the intellectual system of aircraft engines quality provision. Mathematical model of the system with regard to analysis and clustering of complex shapes and surfaces is built. The analysis allows calculating parameters of a part location deviation from nominal geometry, and calculation deviation of parts shapes. Analysis tools are as follows: an iterative algorithm of nearest points, piecewise splines approximation of surface points, Fourier transform. We used an algorithm of k-means and self-organizing Kohonens neural networks as clustering methods. For adequate profile parameters clastering (shape and position) these parameters were normalized to the range of [0,1]. Complex shape geometry intellectual analysis model was implemented in MATLAB®. Within the framework of the developed system using obtained models, clustering of series of GTE backet compressor blades, obtained as a result of measuring with CMMs DEA Global Performance 07.10.07. Implementation of neural networks seems to be more promising for the tasks of clustering solving compared to static methods, due to the possibility of learning and clustering of new objects on the basis of accumulated know-how. For further model realization in manufacturing building of new program modules is necessary | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharov I. V., Trubnikov A. A., Reshetnikov D. A. Methodic prerequisites to the quantitative assessment of technical state of one class of complex technical systems . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 66-73. In terms of the guidance system of the guided aircraft air-to-air missile methodic prerequisites of the assessment of the technical state of one class of complex technical systems were suggested. The assessment of the technical state of the guidance system of the guided aircraft missile commentary was carried out using two methods. The first one was the parameter control method in the universe of linear nonqualified tolerances. The second one was the verifying method on figure of merit in the functional-hardware potential field. The presentation of returns of control was deduced using both accounted methods in the space of parameters specified a combat potential of the guided aircraft missile. The method of the assessment of the technical state of complex technical systems and its instantiation inside of the intellectual technical diagnosis system were in [1- 4] established. In this article the development of the above mentioned approach for the assessment of the technical state of the guidance system of the guided aircraft air-to-air missile was reproduced. In [5] the hybrid control method was offered. Within the framework of this method the current technique of parametric control and cueing on figure of merit were used. For a score of reasons the instantiation to the full the policy of maintenance with respect to state of systems within classic understanding for wide-ranging total of guided aircraft missiles as exploitation objects is impossible. Therefore for the instantiation of operation and maintenance of guided aircraft missiles with respect to state a new method can be used.This method was named " the method of the utmost complete usage of the real technical state of a guided aircraft missile while decision making in situ. The instantiation of such method assumes usage of the multialternative checking circuit: effective — qualified fit — defect, based on the assessment of the technical state of the guided aircraft missile. For this purpose a new notion J was introduced that was nameda combat potential of the guided aircraft missile. J was determined by the total of tactical and technical missile characteristics j1, j2, j3,..., jk, providing its dissemination against specific crowd of goals, under the crowd desired condition of the tactical employment. Thereafter the fault if only one any of parameters X ( of the missile as the unit under test), defined in the space QR(X) of the system of linearly independent permissible limits, spasmodically lower on 100% the whole combat potential of the missile notwithstanding that a limited stamina of the unit under test QR(X) stayed behind. Let us introduce a new mathematical object F — the functional-hardware potential (FHP). F identically specified by the crowd of subsystem duties of the guided aircraft missile. These duties strictly reflect the sequence and the quality of carrying out missions of the guided aircraft missile. The above mentioned crowd was in practice implemented on missile board by defined total of on all fours of instrument room decisions. Let us analyze the class of the guided aircraft air-to-air missile subsystems as persistent dynamic systems in terms of the guidance system. The engineering philosophy of development of the standard guidance system is based on the condition for miss minimum Rh while target homing. Then the design of high performance securing control process is possible on the ground of construction and analysis of mathematical modelsfor the guided aircraft missile as the unit under test using figure of merit W of the true miss. Hence it becomes possible the presentation of a monotonic association between the technical state of S missile subsystems in the figure of high merit space and the combat potential J of the guided aircraft missile. The usage of the multialternative checking circuit: effective — qualified fit — defect does possible the made-up enhancement of Ώ`(X) — the area of observed intermediate technical states of the unit under test. This area features the guided aircraft missile stamina which forms the requirement for the instantiation of advanced the guided aircraft missile performance strategy inside of the modern system of technical exploitation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parovay E. F. Designing of elastic suspension for low-flow tilting-pad journal bearing . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 74-84. Paper is devoted to developing of pad elastic suspension designing methods for pad journal bearing with essentially new action mechanism. Developed bearing is tilting-pad journal bearing operating under oil starvation conditions so it is extremely economical. System state and dynamic stability provides working gap force closure due to tilting pads which are elastically suspended on the material MR insets. Elastically suspended pad journal bearings have the ability to high speeds operation and increased resource. Calculation to determine and optimize the performance of elastic- damping suspension bushings is one of the most important stages of a complex technique of designing these bearings. Elastic suspension material allows pads to turn in the radial direction and to make the best working position. The paper presents the developed mathematical models of working gap — pad — elastic suspension system behavior, created with the purpose of determining the elastic suspension material characteristics, providing bearing optimum operating mode. The mathematical method is developed for determining center of the resultant forces in system working air gap — pad — elastic suspension. The method uses the optimal load value, which is determined by the program calculating results (characteristics of lubricant flow: total pressure distribution along the working gap length). Obtained dependences can be used to optimize the pad geometry and MR characteristics (wire diameter, etc.). Model for determining the optimum characteristics of the elastic suspension material (wire diameter, wire material MR density, load value, etc.) is based on the V.N. Buzitskiy and A.A. Troynikov material MR model and takes into account the design and operational features of the bearing. Optimization of these elastic suspension parameters is a condition of failure bearing operation in mind its low oil flow, supernarrow working gap (from 1-5 mсm) and a mechanism for pad tilting on elastic suspension. On the CFD results basis (oil-flow characteristics, ANSYS CFX) using the developed mathematical models it is possible to determine the required MR characteristics and also the parameters of the MR layer behavior under loading by the pressure in the working gap (ANSYS). Two-dimensional contact model was created for system pad — elastic suspension to determine the strain value. Calculating of material MR stiffness C is based on experimental data. Expression for C is used to set the MR Youngs modulus dependence from the magnitude of MR deformation. The hydrodynamic load W = f (φ) is determined by the results of the flow characteristics calculation (pressure distribution along the length of the working gap). Distributions of radial and equivalent stresses, radial and total displacements (deformation) in the system were obtained. Through construction and investigation of the developed models characteristics the possibility of this technique is extended to the elastic suspension parameters optimization by various criteria. Established complex model of the system working gap — pad — elastic suspension allows to solve problems of associated hydrodynamics, thermal analysis and deformation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pugachev A. O. Simplified approaches to brush seal leakage evaluation. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 85-93. The paper presents semi-empirical and theoretical methods for brush seal leakage performance evaluation. It also describes suggested simplified approach based on the reevaluation of the effective clearance value for the sel ected generic brush seal of the design that corresponds most closely to the studied seal. Besides,the paper describes the simplified CFD-based porous medium model of the gas flow in brush seal developed in free and open source software, allowing performing the analysis in automated mode. The proposed simplified approaches are practical tools for evaluating leakage performance of brush seals without excessive time consumption. The preliminary design approach is based on the experimental data on leakage and blow-down behavior of six different configurations of brush seals. Experimental dataset is supplemented by the predicted calculated relationships for the brush pack compression. In spite of the limited set of the generic brush seals, the proposed preliminary design approach demonstrates a satisfactory agreement with the data for other brush seals taken from free access literature. The simplified CFD model is used to obtain pressure and flow fields in the brush seal channels. The application of the proposed approaches is illustrated using the data on the original design of brush seals developed at IVCHENKO- PROGRESS SE. The results show that a reasonable agreement can be achieved for the brush seals of that differ significantly fr om the designs of brush seals forming the basis of suggested approaches. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rogov D. A., Latysh S. I., Vasyukov M. V. Development and design choice of ceramic rocket fairing and metal bulkhead joint. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 94-102. The paper considers problems of selection of the joint of ceramic shell and metal bulkhead of nose antenna dome, that meets the condition of available analog design rethink minimum, while maintaining all the geometric dimensions of parts used. We show by calculations the process of design styles selection with further optimization of their geometrical parameters. Application of the other constructional materials used for a given assembly is inadmissible on radio engineering and mass considerations. The results of computational optimization have been proved by the field tests of prototype items. Based on the results of the prototype air-to-air missile tests, the frame design has been corrected, and the maximum stresses in the ceramic shell of the fairing with the frame of corrected design have been determined. Application of modified frame together with the maintenance of air-tightness contributes to the product weight saving and stresses reduction in the ceramic shell, as well as improves the production effectiveness of the frame assembly. At operation mode of 110 s duration maximum temperature of the inner attachment frame heating changes from 220 °C (at the shell edge) to 340 °C (in a thin part of the frame). The maximum tensile stress in the shell caused by the temperature is 15 MPa, and the maximum tensile stress caused by the force factors does not exceed 9.5 MPa. The total maximum tensile stress in the shell at the end of the operation mode is 17.3 MPa in the circumferential direction and it is 15.85 MPa in the meridian direction. With all abovementioned taken into account, we recommend to accept the proposed design of the frame and to refine it with the aim to determine optimal geometrical parameters and develop the technological process which will make it possible to meet all the requirements of the frame design specification. After analysis of frame design advantages and disadvantages, we plan to develop a new variant of the frame design with the following positive characteristics of previously analyzed structures, which will provide:
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Kraskovsky N. V., Samsonovich S. L., Tchubikov V. N. Comparative analysis of the unidirectional action mechanisms designed for electromechanical actuators. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 103-114. A comparative analysis of the unidirectional action mechanisms, which include the irreversible motion clutch, self-braking electromagnetic clutch and transmission, is carried out. The purpose of the analysis is creation of an electromechanical drive of unidirectional action, which has the reduced power consumption, compact design, lower weight and improved dynamic power characteristics, for its use in control systems of aircraft of the new generation, rotation of power plants, jet rudders, flaps of water and oil regulators, and etc. According to the presented theoretical research the following conclusionscan be made:
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Bologov D. V., Prokopenko A. V., Sutormin A. Y., Fetisov G. P. Finishing plasma strengthening of tools, dies and molds. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 115-120. This work investigates the possibility of strengthening of production tooling, used for aircraft engine parts production, and cutting tools by diamond-like coating. We have developed diamond-like thin-film coating technique for the finishing plasma strengthening based on disintegration of liquid technologic agents vapors, ins erted into an arc plasma gun followed by plasma- chemical reactions and formation of product coating. We used metal-organic and organic compounds in liquid state as parent substances for providing diamond-like coating based on silicon oxycarbonitride. We choose argon as an orifice gas, used in arc plasma gun. The applied coating duplicates the substrate profile, and strengthening coating herewith is formed as an optically transparent film. We investigated comparison characteristics of adhesive properties of diamond-like coating and titanium nitride coating applied by ion-plasma sputtering in vacuum. As a result of our investigations we found that the val ue of critical load initiating first chips and delaminations equals to 35N for titanium nitride coating and 65N for coatings applied by diamond-like thin-film coating technique. We found that being a dielectric itself the applied diamond-like coating forms a film barrier preventing stiffening of conjugated surfaces. Besides, this coating possesses higher corrosion stability and heat resistance. This fact is confirmed by numerous long-term atmospheric corrosion tests of samples under temperatures up to 1000 — 2000 °C. For friction and wearout tests we used samples 38 mm in diameter and 12 mm thick made of steel P6M5 coated by means of diamond-like thin-film coating and titanium nitride coating applied by ion-plasma sputtering in vacuum techniques. As a counterbody we selected samples made of steel SHH15 heat-treated to the hardness of HCR 63. Contact conditions were as follows — rolling friction with 20% sliding with lubrication. The tests were carried out at 1000 min-1 rotation frequency and 1650 N load. For comparison, we also used a sample made of heat-treated steel P6M5. In the course of the experiment, the values of friction torque and mass wear of the samples were registered, and friction coefficients and wear rate were calculated. Based on tests results we determined that the friction coefficient of the surfaces with diamond-like coating is two times smaller, compared to reference surface of steel P6M5 and 17% less than for the surface with titanium nitride coating applied in vacuum. The wear rate is reduced by 46% and 16% correspondingly. Due to the obtained data we came to a conclusion of the expediency of application of the developed technique for strengthening of production tooling and cutting tools in various industries, and for aircraft gas- turbine engines parts manufacturing in particular. The developed technique was tested at the number of enterprises, and its application showed 3-6 times increase in production tooling and cutting tools durability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kondratenko V. S., Tretiyakova O. N., Shevchenko G. Y. Development of tools for the controlling laser-processing equipment with a various kinematic schemes . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 121-131. The development of new technologies and equipment for laser processing of aircraft materials during the creation of aviation and space technology products of new generation is an urgent task. The development of new laser technologies requires the creation of highly technological equipment, integrating mechanics, electronics, automation and information technology. The control system is an integral part of the machine with intelligent control of their functional movements. Application software, which includes the qualitatively new modules, ensures the implementation of the control system of laser processing unit, and allows to create equipment for new processes. Speed laser processing and cutting machines are widely used in the creation of elements and devices for aviation and space technology. Article is devoted to the development of application software to manage the new process of laser controlled thermosplitting, as well as technological processes for laser cutting and processing of materials in the new industrial equipment. The basis of the control system is a laser processing equipment software LaserCNC designed for different processes such as laser-controlled thermosplitting. The enterprise Lasers and equipment TM has created a new industrial plant MLP1-1060/355 for the implementation of a new precision separation process of plates made from brittle materials based on the use of a new method of laser controllable thermal cleavage, which uses two lasers: one is to separate the plates, the other one is for the initial application defect for crack initiation. Developed software LaserCNC for control system of the laser technological complex MLP1-1060/355 is possible to implement the innovative industrial equipment for the new LСT technology. The LaserCNC software supports different laser processing equipment and, also, can be used for the new multi-axis kinematic systems. The control program for systems with more complex kinematic scheme is DopOs1, and there is DopOs2 for multi axis machines with additional kinematic axes. The basis of the control system is the laser processing equipment software LaserCNC, DopOs1, DopOs2 designed for different processes, such as laser-controlled thermosplitting, laser cutting and material processing. This software is designed for industrial laser-processing equipment with various kinematic schemes. Creation of systems with more complex kinematic scheme will provide a significant improvement in dynamic performance and accuracy required in processes of laser cutting and material processing without cost increase due to the use of more powerful drive. The use of modeling program DopOs2 will make another step in the design of new industrial laser processing unit with additional kinematic axes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komkov V. A., Kokoreva O. G., Kursakov A. V. Investigation of possibilities to harden thin-wall elements of flying vehicles by surface plastic deformation. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 132-136. The paper presents the results of flying vehicles high-ratethin-walled elements surfaces hardening by surface plastic deformation. Investigations of mechanical-and-physical properties of metal surface layerat hardening by surface deformation were carried out. The depth of hardened layer under optimal surface processing rates by hardening with surface plastic deformation. We establish the relationship between quality characteristic of surface layer with endurance and durability of machine component parts, and performed their quantitative assessment. Investigations were carried out and positive results were obtained, which allow manufacturing application methods of hardening by plastic deformation for a number of critical parts. These investigations included pilot parts hardening under different modes in laboratory conditions with bench testing and machines with pulsators to compare these parts endurances, as well as under manufacturing conditions with carrying out appropriate comparison performance test ofendurance. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Degtiarev S. A., Kutakov M. N., Leontiev M. K., Popov V. V., Romashin Y. S. Consideration of contact interactions when modelling stiffness characteristics of roll bearings. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 137-141. When solving rotor dynamic tasks of rotating machines including aviation gas turbine engines, calculation accuracy of the system elements is highly important. One of the most widespread elements are roll bearings. In the first place stiffness characteristics of roll bearings are determined by the contact phenomena appearing between rolling elements and rings. As a whole the other elements of the roll bearing (such as inner and outer rings) influence stiffness no more than 5%. Interaction between the roll and the ring may be considered as linear contact between two cylindrical solids with parallel axes. For the first time solution for this task was obtained in the Lunberg- Sjövall paper [1]. However, equation in [1] has implicit dependence of outer force on appeared displacement and so cannot be used for tasks of stiffness characteristics determination. In Harris work [2] empirical Palmgren equation [2] was used to solve this task: , where — contact force, — contact length, —displacement in contact line. To verify results in paper [2], the task of contact interaction between a half cylinder and a plane was solved using FEM. It was obtained that there was significant divergence (up to 30%) between solutions obtained using Palmgen’s equation and FEM. It was found out that Palmgren’s equation was correct with error of 5% for lengths of contact lines from 10 to 20 mm. According to the results of the FEM solution, the new dependence for linear contact tasks was proposed. It gives no more than 4% results’ divergence in the contact lengths range from 0,5 to 50 mm. . The obtained dependence may be used to simulate stiffness characteristics of the roll bearings and to describe linear contact in tasks of contact interaction mechanics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Istrakova A. R., Kashapov O. S., Kalashnikov V. S. Study of heat-treatment regimens influence on structure and phase composition of disc forgings for «Blisk» made of alloy VT8-1. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 142-151. The main purpose of the materials research in the aerospace industry is to improve the structure reliability while reducing the weight. Heat-resistance titanium alloys with a density of about 4,5 g/cm3 can facilitate engine weight, but titanium and its alloys have polymorphism, which limits the application temperature of the alloys in 0.6 times then polymorphous transformation temperature. A heat resistant titanium alloys can continuously operate at temperature of 500 550 °С, depending on the chemical composition of the alloy, the process conditions of heat and deformation processing. Discs and the compressor blades made of titanium alloys where used in aircraft gas turbine engines. Further reduce of weight of the engine can be achieved by replacing the classical design of the compressor stage with removable blades by blisks. This article examines the impact of different modes of annealing on structure, phase composition and mechanical properties of the samples of punching blisks. Raising the temperature in the first heating stage at ten degrees Celsius and lowering the heating temperature in the second step of annealing from 590 to 550 °C reduces the volume fraction of primary á -phase and 50% in batch annealing to 2025% reduction in the thickness of the secondary plates á — phase and increase the length of the interphase boundaries. Using transmission electron microscopy it was found that when adjusted mode annealing at interphase boundaries silicide particles are not detected. By increasing the efficiency of solid- solution and precipitation hardening is provided by increasing: the strength of 120 MPa at room temperature and 70110 MPa at elevated; rupture strength at 500 °C at 75 MPa; low cycle fatigue at 20 °C for 20 MPa high cycle fatigue at 20 °C at 30 MPa. At the same time, due to changes in the structure and phase composition, sensitivity to stress concentrators during the impact test is reduced. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ryabov A. A., Romanov V. I., Maslov E. E., Strelets D. Y., Kornev A. V., Ivanov A. I. Comparative analysis impulse deformation of aircraft structure elements made of aluminum alloy and composite material. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 152-161. The necessity to increase weight effectiveness of new aviation structures encourages permanent structures modification and development implementing new materials, including composites. Some elements of these airplane structures can be subjected to impulsive loading. Thus, the investigations of dynamic deformation of shells and plates made of composite materials loaded by the impulse pressure are important. As long as the great majority of structures was made in the past of aluminum alloys, it is rather interesting to compare their deformations with those of new stuctures made of composite materials under the same loading to identify the differences and advantages. The goal of the presented article is numerical and experimental investigations of two plates made of aluminum and composite materials, loaded by equal impulse pressure with maximum amplitude of 6-7 Bar order and 0.3-0.4 ms duration. The composite structure is made of three layers: two outer plates of fiber- reinforced polymer, linked by honeycomb stuff. We realized numerical simulation is performed on the basis of explicit integration schemes of the equations of motion in time domain and finite element sampling in space in LS-DYNA application software package. Eight-node of Sollid type and four-node finite elements of Shell type are used for sampling. The problem is solved in the Lagrangian formulation. We used Chang- Chang orthotropiс model with possible brittle fracture for composite material. Тhe accuracy of numerical solution is confirmed by the precision of calculation data and experimental results. Comparative analysis shows that numerical and eхpеrimеntal сurvеs of deformations in several sеlесted points are close to each other. Aluminum and сomposite platеs of diffеrent sizеs are deformed by thе samе dynamiс lоad up to maximum levеls of dеformations lеss than 0.2%. Numеriсal and eхperimental rеsults show that aftеr impulsе loading removal thе platеs keep on their oscillatory motion with the lowest fundamental frequencies. In the еxperimеnts thе period of osсillation damping is about 180-200 ms for aluminum platе and about 40-50 ms for сompositе plate. The three-layer compositе plate demonstrates four times higher damping effect compared to aluminum plate. From the above said we can conclude that numerical calculations of dynamic deformation of composite plate based on Chang-Chang orthotropiс model allow obtaining acceptable results. Further improvement of modeling quality can be achieved by more detailed description of honeycomb stuff.
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Kurennov S. S., Tanchik E. V. Calculation of the stress state of а glue joint of rectangular plates with different widths. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 162-169. The article is devoted to the issue of the dayconcerning calculation of the stress state of the overlapping glue jointin two-dimensional formulation. The purpose of the work is to solve the problem of glue jointstress state of symmetrical rectangular plates with different width under longitudinal load. For the first time we obtained the solution of the problem in analytical form. To build the solution we used simplified Volkersentwo-dimensional model, according to which connecting layers are considered to be rigid in transverse direction. The hypothesis of the plates rigidness in transverse direction was implemented earlier for creation refined theory of beams. The author developed this theory for connection of two plates. The outer layers work only in tension and compression in the longitudinal direction and shift. The adhesive layer is a shear layer. The stresses assumed to be constant over the thickness of the glued layers. The stresses in the adhesive layer are proportional to the difference between the displacements of the outer layers. Due to joint symmetry and imposed stiffness layers hypothesis, there is no movements of layers in the transverse direction. In the gluing area, the stress state is described by a system of two, second order partial differential equations with respect to the longitudinal movements of the outer layers. Outside the gluing area the movements of a wider layer are described by a second order partial differential equations with respect to the longitudinal displacements. Solution of the equations is build as a series expansion in the eigen functions. Eigen values are found fr om homogeneous boundary conditions at the lateral sides of the connection and the conjugation conditions on the lim it of the bonding domain and the outer edge of wider plates. The corresponding eigen functions are not orthogonal. Coefficients of the series are found from the orthogonality condition of the residual vector of boundary conditions to the eigenfunctionsvectors. The model problem is solved, and the obtained data was compared with calculations based on implementation of the finite elements method. Calculations have shown that the accuracy of the method is sufficient for designing such connections. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pomogailo D. A., Spirin M. G., Skobeeva V. M., Dzhardimalieva G. I., Smyntyna V. A. Spectral-luminescent properties of CdS nanocomposites in a polymer shell. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 170-177. Nanocomposites of different concentration of cadmium sulfides nanoparticles in polyacrylamide shell were obtained as a result of interaction of cadmium nitrate with acrylamide and sulphonating agent (thiourea) in certain stoichiometric ratios and subsequent thermal polymerization of the reaction mixture. The samples were studied using methods of elemental analysis, X-ray diffraction, scanning electron microscopy, optical and fluorescent spectroscopy. The size and distribution of sulfide nanoparticles in polymer were defined. X-ray diffraction analysis of nanocomposites obtained revealed the following reflections at 2Θ: 26.35; 43.85; 51.85 with the values of d equal to 3.357; 2.085; 1.756, characteristic for hexagonal cadmium sulfide with wurtzite structure. Intense broadband at 2Θ = 21 belongs to polyacrylamide. It is characteristic that the intensity of CdS-containing phase peaks decreases with the increase of cadmium sulfide concentration in the composite with a simultaneous increase in the interplanar spacing. It proves nanocrystals binding with a polymer matrix. The average crystallite size (nanoparticles), corresponding to the sizes of coherent scattering of X-rays ranges, were evaluated at the width of the reflections in the diffraction patterns according to Debye-Scherrer formula. Particles size varies within a narrow range of values and ranges from 4 to 15 nm with increasing of the CdS share in the composite. Increasing of the CdS concentration reduces the particles size of the CdS crystallites. Submicroscopic image of nanocomposites containing different concentrations of cadmium sulfide nanocrystals indicates a noticeable effect of nanoparticles concentration on the surface morphology. That is, increase in the cadmium sulphide concentration leads to an increase in the compactness and structuredness of the composite. It was shown that the absorption spectra has characteristic features of the spectra of composite systems with nanosized semiconductor crystals, which show «defective» luminescence with maximum in the range of 550–570 nm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko A. N., Makhrov V. P. On the way to eleсtriсally driven aviation era. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 178-187. This article examines the new type of the aircrafts — electrically drivenaircrafts (electro-aircrafts).Presented two trends of development of present-day electro- aircrafts, which use electric energy for mission operations. The first trend lies in meansimplementation ofsolar radiation energy by converting it on-board into electric energy by means of photoelectric converters allocatedon the surface of the aircraft. The second trendisimplementation of the electric energy stored on boardin batteries. Each of the trends include either manned or unmanned (UAV) prototypes of electro- aircrafts. From the first trend, so-called solar UAVs (or SUAVs) have widely spread in the forms of sport model aircraftsand industrial designs. The paper presents NASA achievements in the field of electric UAVs, designed in the course of its twenty-year ecology program ERAST, which at present time has expired. It also observes NASAs challenges for the development of such aircrafts in the future. The paper examines design features of SUAV Helios HP01. It is noted that even at a low value of efficiency of solar batteries SUAV can be competitive with satellites for monitoring the Earth surface. In addition, the paper notes the works with UVA carried out in MAI. The layout of the first Swiss man- carrying aircraft driven by solar energy, which was in flight within 24 hours is presented. The second trend of electro-aircrafts development was presented for the first time at Berlin ILA-2014 exhibition by two existing prototypes. The main attention there was focusedon the electro-aircraft E-Fan, presented by the Airbusgroup. This flying vehicle can be considered as a prospective for ecological transport aviation. The paper presents its technical characteristics, and marks its design features based on composite materials, Li-Ion batteries, allocated in the wing, and original propelling screw. Austrian firm Diamond Aircraft Industries involved in the development and creation of small aircraft prototypes presented its vision of on-board electric power source. At Berlin exhibition, it demonstrated its electro- aircraft LANDE with promising on-board battery, based on hydrogen fuel cells, similar to those used in the space industry. It is noted that such power systems were designed for UAV at MAI. Experts believe that in the future hydrogen energy sources will replace batteries for electric transport helicopters. Helicopter firm Agusta Westland designed, manufactured and tested with electric system and original structure of the flying wing type with two swivel propellers for vertical takeoff and landing. Two micro UAVs, built by helicopter and aircraft schemes with electrical on-board systems-MIKADO and ALADIN correspondinglywere presented at Berlin exhibition. These flying vehicles have small mass and size, and are intended for near-field reconnaissance by one fighter. They were tested in Afghanistan for air reconnaissance, mapping and other military operations. At present, armies of Germany and NATO have a great number of such aircrafts. All prototypes of electro-aircrafts presented are promising. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ilyuhina N. S., Frolov A. A., Iluhin A. S. Investigation of electromagnetic field patterns of electromechanical transducers of rotary type. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 188-193. This work aims at the analysis of the rotary electromagnet structure through the research of electromagnetic field patterns by finite element method. Based on the results of the analysis we built a general equivalent circuit of a magnetic circuit, enunciated assumptions necessary to build non-linear mathematical model as well as electromagnet of rotary type design. The analysis of numerical values streams obtained as a result of electromagnetic field modelling in a system with neutral electromagnets shows that in most cases stray and bulging fluxes appear to be commensurable with working fluxes, and, thus, they need to be taken into account when calculating the static and dynamic characteristics. In the electromagnet under consideration, the stray flux is almost constant during the movement of the armature. It allows supposition on stray conductivity uniformity. On the basis of the analysis of electromagnetic fields patterns and assumptions, we build a non-linear the electromagnet mathematical model. Research of electromagnet dynamic characteristics was carried out numericaly using non-linear model for ambient temperature vatiation of ± 50°С and power source voltage within the specified tolerance range. Mathematical model obtained and developed software can be implemented to analyse currently available as well as newly designed electromagnets. The developed mathematical model takes into account the peculiarities of magnetic field configuration of each electromagnet design implementation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Izyumova I. V. Features of corporate relations in the Russian aviation industry (20 years after the beginning of radical economic reforms). Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 194-202. Realization of reforms in the science-intensive business is accompanied by associating of existing enterprises and the creation of new ones. The rules of law, corporate and professional codes govern the corporate relations between enterprises. These relations are characterized by a certain degree. These relationships between enterprises are characterized by a certain degree of dependence on interaction with each other. For the Russian aviation industry, the role of the state at an early stage of economic reforms seems of less importance compared to the times of the USSR existence as well as leading world economies. Since the beginning of economic reforms, production volume of aircrafts has declined significantly. The quality of designs deteriorated, and for the most part represented an adaptation of previously designed products. Commercial aviation manufacturing became dependent upon constituent parts of foreign manufacturers. Defense technology designs achieved more recognition since they are related to the sixths generation. Research and development activities significantly decreased, and breakthrough innovations were replaced by a step-by-step modernization. For research and development effort organization everybody stuck to the principle of so-called pulling-out. Taken together, it led to intellectual potential reduction, transition to works, related to designs of small batches of aviation products manufacturing, independent search for orders, and consumer goods design. At the early stages of the reform of educational institutions, a significant outflow of personnel was noted. This outflow of personnel had a significant impact on training. The conditions of admission to educational institutions and training have also changed: training on a commercial or budget basis and targeted training were offered. New forms and training technologies are used. The number of graduates of educational institutions did not and do not meet the demands of the industry, academic and sectorial research institutes for the specialists of appropriate qualifications. Over the past 10 years, the federal government adopted standards for training, the implementation was carried out only by scientists and teachers of high school. State program of development of the aviation industry for the period from 2013 to 2025 with the subprogram 7 Aviation Science and Technology is aimed at solving problems arising in corporate relations in the period of reform. Implementation of reforms in high technology business association is accompanied by existing businesses and creation of new ones. Corporate relations between companies are governed by rules of law, corporate and professional codes, characterized by a certain degree depending on the interaction with each other. Role of the state for the Russian aviation industry in the early stages of economic reform is recognized lower compared to the time of the Soviet Union and in comparison with the worlds leading economies. Since the beginning of economic reforms, production of aircraft has declined significantly. Quality development deteriorated and is a modification of previously developed products. Production of civil aviation has become dependent on the components of foreign origin. Developments in the field of military equipment reached more recognition, they are referred to the sixth generation. In the manufacture of preserved preference of domestic components. Research and development activities significantly decreased, breakthrough innovations are replaced by a step by step modernization in the organization of remained the principle of pull. Overall, this resulted in a reduction of intellectual potential, the transition to work-related developments for the production of small batches of aviation products, independent search of orders and product development of national purpose. In the early stages of the reform of the educational institutions there is a significant outflow of personnel, which affects the quality of training. The conditions of admission to educational institutions and training have also changed: offer training on a commercial basis or budget, conditions targeted training, new forms of technology and training. The number of graduates of educational institutions did not satisfied and do not meet the needs of industry, academic and industrial research institutes in frames appropriate qualifications. Over the past 10 years, Federal State Standards for training of specialists were adopted, which implementation was carried out only by scientists and teachers of high school. The State Program of development of the aviation industry for 2013-2025 with the Subprogram 7 Aviation Science and Technology is aimed at solving problems arising in corporate relations during the reform | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalenko A. A. Innovation activity management at the enterprises in the context of national innovation system development. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 203-213. This article deals with developing of knowledge about innovation management mechanism in the context of researching national innovation system. We studied key factors that influence innovation process at the enterprises. We tried to develop key factors that help people in their innovation activity and that stem the tide. It was in our interest to define key factors that help the process of knowledge diffusion at the enterprise. Motivation, as we know, is the key element of innovation management mechanism. Also we studied innovation culture and some notions of it. First, we studied some researches in the sphere of social oriented mechanism of innovation management as Russians authors and foreign. We tried to define key factors — motivator for innovation process so among shareholders and management, so among liner managers and specialists. We made expert survey using structured questionnaire. The number of experts was more than forty. We define the expert as a specialist with working experience in the sphere of innovation activity in different area of economics passed special courses of innovation management and having MBA or PhD degree. We found out that in very large companies the most important factor that prevents the innovation process is the lack of financial recourses, high cost of innovation, not enough government support. In amount of middle, small and little companies the most important factors are: support of management, composition of project team. We point out that knowledge management play the key role in innovative process and the key factors helping knowledge diffusion are support of company management and affiliation to some innovation team. Innovation culture is associated with such notions as management participation in innovative process, fair incentives system, atmosphere of trust and striving to personal growth of each member. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Efimova N. S. Formation of information support methods for processes of science-intensive production development in the conditions of enterprise information security. Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 214-221. Introduction of cycle life support processes of science-intensive production into an aircraft industry is an actual problem at the enterprises of the aviation industry, becauseat the present time many enterprises of aircraft industry are faced to the problem to chose the integrated information system for increase of enterprise activity efficiency. The basic principles for introduction of the integrated information management systems are defined by tasks and features of the aircraft equipment production, and, also,by specifics and development of modern methods and means. In this regard the main objective of introduction of information support into life cycle processes of aviation products is finding of an optimum combination of separate methods and means of information technologies. During the solution of the mentioned economic problems the information technologies, which are directly aimed to support of productions at all stages of life cycle of the created science-intensive aviation production, have the great importance. During the analysis of vital processes of the science-intensive production of aircraft industry it is revealed that the full- scale introduction of the integrated information systems at various stages of life cycle of the aircraft equipment is capable to bring to the developers, producers and customers the following advantages: at the design stage of products, tests and operational development, and also technological preparation of a mass production — the possibility of reduction of duration and cost of the listed stages, possibility of flexible change of a design of products and technology of their production; possibility of formation of the virtual enterprises and flexible change of their structure for the purpose of ensuring low deficiency and purchase price of accessories; possibility of optimum planning of processes of maintenance, and also material support of their operation; possibility of the organization through imitating modeling and optimization of life cycle of the aircraft equipment since its earliest stages. Realization of the principles of information support of the science-intensive production is possible only in the case of complex introduction of information technologies at all stages of life cycle of production of aircraft industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Tran Q. D. The study of static and dynamic characteristics of atmosphere pressure measuring in airspeed tube . Aerospace MAI Journal, 2015, vol. 22, no 2, pp. 15-24. Operation of air data system (ADS) assumes the application of atmosphere static and dynamic pressure measurement affecting an aircraft. At present the type of airspeed tube construction and a place of its mounting are selected through experimental research in wind tunnel [1, 2]. With computing technologies development, we got the possibility to predict gas pressure distribution over aircraft surface depending on an aircraft design, flight conditions and aircraft state vector [3, 4]. Pressure distribution determination over aircraft surface using up-to-date software is a relevant task, allowing advance in mathematical design of ADS and substantially reduce the extent of experimental examinations, providing high accuracy of measurements due to more detailed measuring process models. Having calculated pressure distribution over aircraft surface with due account for change stipulated by deflection of incidence angle and gliding, velocity, Reynolds number, etc, one can optimize the point of airspeed tube mounting, as well as provide theoretical calculations of pressure measuring error. All this contributes to compensating this error programmatically with ADS onboard computer. The goal of this work consists in obtaining static and dynamic characteristics of processes taking place in airspeed tube. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korizhin O. V. The method for aerodynamic characteristics calculation of stores, which are separated from the aircraft . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 7-13. The provision of store release safety is one of the issues that arise during the development of aircraft store transportation and separation systems. In general the safe release refers to fulfilling the following requirements during the store flight in the vicinity of the carrier after its release from the launcher: — elimination of the possibility of collision of the store with the airplane itself, its structural elements or stores, which are installed on the adjacent suspension points; — retention of the store spatial stability on the initial segment of its flight path in the vicinity of the carrier; — absence of thermodynamic impact from the exhaust jet of the store engine on the structure of the airplane itself,its propulsion system functioning and other stores. It is possible to solve the problem of store separation safety at the stage of transportation system design and release method development. The appropriate solution method is based on the analysis of the results of modeling of store spatial movement in the vicinity of the airplane. At that the reliability of aerodynamic characteristics of the isolated store and flow, which is disturbed by the plane, is important for the simulation. As a rule it is necessary to conduct wind tunnels tests to obtain aerodynamic characteristics. Reliable determination of safe release modes requires conducting a large number of tests at different angles of attack, sideslip angles and Mach numbers. The presence of folding aerodynamic elements of various configurations on the suspended stores increases the amount of required wind tunnel experiments dramatically. Thus, the determination of aerodynamic characteristics of isolated bodies and interference can take a long time. Conducting tests is generally not feasible at the early stages of system design under uncertainties of some design parameters. In this case it is expedient to use computer technologies, namely, computer engineering methods. Such methods provide reliable analytical support through the use of software suites, which are focused on computational analysis of gas and fluid dynamics (CFD). The software system, which performs CFD analysis and processes the virtual experiment results, was applied to the analysis of an external fuel tank. Such fuel tanks are widely used on various types of aircraft. Virtual simulations were conducted in a wide range of angles of attack, angles of sideslip and Mach numbers. The results were processed by using a multidimensional (multivariate) interpolation function. Such function allows the research team to calculate the values of the aerodynamic coefficients for the entire range of angles of attack, angles of sideslip and Mach numbers. The relevance of the obtained aerodynamic characteristics was confirmed by the comparison with the available data of the wind tunnel tests. The comparison showed good consistency between the calculation by CFD method and full-scale experiment. Slight differences are most likely associated with the following circumstances: — ascaled-down model of the fuel tank was tested in the wind tunnel, — presence of a methodological error in the algorithm, which was used for solving the equations, — presence of methodological error in the algorithm of gas flow simulation, — the three-dimensional solid model was simplified for the analysis. The described method allows the designers to determine the aerodynamic characteristics of the stores at early development stages without conducting the wind tunnel experiments.This can reduce the cost of wind tunnel tests and time, which is required for optimization of the store aerodynamic configuration, significantly. Application of the proposed multidimensional (multivariate) interpolation allows the designers to calculate the coefficient values for any angles of attack, angles of sideslip, Mach numbers, geometrical configurations and other initial data within a pre-defined range. The application of the described method allows the researchers to calculate the aerodynamic characteristics of both newly designed and existing aircraft in a wider range. All of the mentioned above confirms the efficiency of computer engineering methods, especially at the early stages of aircraft design | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Tran Q. D. Turbulence model validation for calculation of flow parameters and aerodynamic characteristics of a passenger plane . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 14-20. The purpose of this work is to validate model of airflow over passenger aircraft aerodynamic using the ANSYS FLUENT software package (license number: 00632255). The paper examines two models of a flown around object: LL 6945 fuselage model [1] and TU-154B passenger aircraft [2]. All investigations were performed using the following parameters: angles of attack, α = 0...20°, Mach numbers: 0,2 < M < 0,8, Reynolds number: 7·106 < Re < 28·107. The flow in the vicinity of the examined models, LL 6945 fuselage and TU-154B was assumed to be turbulent. Calculations of the flow parameters and aerodynamic characteristics were made using the following models of turbulence: Spalart-Allmaras model, «SST k- ω», «k- e ». Calculation results obtained with ANSYS FLUENT were compared with experimental data. It was found that calculation results using the «SST k- ω » model match in the best way with experimental data and describe the variations of the aerodynamic coefficients with respect to the angle of attack in comparison with other models of turbulence [1, 2]. Constants which give the best convergence of calculated and experimental data are determined for the «SST k- ω » model. The results obtained will allow application of this flow model to optimize pitot-static systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorbatenko S. A., Klionovska K. K. Fault detection and identification technique in control systems with redundant inertial measurement unit . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 21-28. Development of aviation technology requires the use of a variety of measuring systems to determine the motion and positioning variables of the aircrafts in the space. Requirements for the reduction of weight and dimensions of such systems are the first since the objects themselves demonstrate a tendency to reduce their weight and size characteristics. Availability of inertial measurements units (IMU) allows to create tiny strapdown inertial navigation system (SINS), which have small weight and dimensions, and can be used in areas such as attitude control system, radar, avionics, data transmission system, navigation, etc. The work of these systems is accompanied by a variety of errors and failures, which leads to the urgency of early detection and recognition of their errors. This difficult problem can be solved on the basis of different approaches and with varying degrees of success. The article describes one of the possible ways to solve this problem, such as using combination of two methods like a parity space approach and the discrete wavelet transform in the redundant system with additional IMU. Such combination allows to detect three faulty sensors and to isolate each of them out from the system during the system operation. The one of the positive advantage of this algorithm that it is not demanded to know the dynamic of the system model, except orientation of the sensors in the measurement system organized with redundant IMU. The simulation of the successful operation of this algorithm with two types of sensor faults, such as bias and stuck, are demonstrated in this work. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Busurin V. I., Kazaryan A. V., Pham A. T. Performance analysis of optical micro electromechanical angular velocity sensor . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 29-37. The article describes optical micro electromechanical(MOEM) angular velocity transducer, representing a solid-state device having vibration console, with the ability to deviate. This transducer allows determine magnitude and direction of angular velocity by using Coriolis force effect and optical information reading. Coriolis force is acting on the piezoceramic sensitivity element during rotation of the MOEM transducer, causing its deviation over the axis, positioned on vibration plane and directed perpendicular to the plane along the longitudinal axis of the console. Material and dimensions of sensitive piezoelectric element (SE) should be such that the resulting deflection of its parts does not exceed hundreds of nanometers. The highly sensitive optoelectronic circuit for information retrieval about angular velocity with the purpose of obtaining more accurate information should be herewith based on optical tunneling effect (OTE), allowing fixation of a small measured displacements. The structural model of uniaxial MOEM angular velocity transducer is described. The impact of the Coriolis force on SE is calculated depending on various design parameters and piezoelectric materials. For a SE in the form of a plate deflection has no strong dependence upon the temperature, and vibration element longitudinal oscillations amplitude linearly depends on the coordinate along the longitudinal axis and exciting AC voltage. Simulation results showed that numerical values of the deviations can be obtained within the range of several hundred nanometers, which corresponds to the value of the optical radiation wavelength. Thus, angular velocity transducer can be designed on the basis of optical tunneling effect, which provides greater sensitivity when measuring small angular velocity. The above characteristics analysis shows that the material with the brand ZTC-19 having larger piezoelectric module and higher stability within the working range of temperatures and pressures, can be used in MOEM angular velocity transducer based on OTE. We examined characteristics of the transducer, using SE with additional mass to improve its sensitivity. With structural dimensions decreasing it is necessary herewith to increase the value of additional mass to provide greater sensitivity for measuring small angular velocities. With the same sizes and materials introduction of additional mass m = 5·106 kg, SE end deviation under the influence of the measured angular velocity will be 1,5 µ m, which is hundred times greater than in the case without the additional mass m. It also provides the possibility of organizing an optical information reading by means of optical tunneling. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kim N. V., Bodunkov N. E., Prokhorov P. D. Real-time image processing and analysis of highly dynamic objects . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 38-46. The problem of surveillance and search of highly dynamic objects based on the image processing and analysis of video in real-time is considered in this paper. By highly dynamic objects, we mean such objects, which interframe shift exceeds their correlation radius. The realtime operation condition depends on the current task specifics, and can be expressed as a required dynamic objects computational efficiency (the amount of elementary operations) of the search algorithm. As an example we examined search correlation algorithm MAD and search algorithm SIFT based on descriptors. We carried out studies of these algorithms and specify conditions under which these algorithms would fail to provide realtime condition fulfillment. The highly dynamic objects search algorithm ensuring realtime operation under these conditions is presenter in the paper. The advantage of the proposed algorithm lies in significant reduction of elementary operations due to required object descriptions presentation in the form of star pattern of characteristic points. It is shown that proposed algorithm has higher computational efficiency than correlation algorithms and algorithms using descriptors. We carried out experiments of real time objects tracking, and determination of the blade edge position of helicopter propeller. The experimental results show the efficiency and effectiveness of proposed algorithm application for tracking and tracing problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Markin L. V. Geometric models of automated layout aircrafts . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 47-57. The article reviews a problem of layout design automation for aerospace engineering. It is shown that the complexity of this process is stipulated by the difficulty of information representation concerning geometric shape of an object being arranged in the computer. The article presents the main types of geometric models describing the shape of objects being arranged, their classification and application areas. We describe an automated layout problem as a problem of placement of a certain group of objects of specified sizes and shapes within a confined space. The task of automated layout is formulated as mathematical programming optimization problem of for maximum allocation tightness of objects being arranged. We present optimization criterion of this process that is space factor of a space being arranged by objects allocated inside it, as well as limitations of this optimization problem. The article also describes well-known methods of automated layout. Powered by article analysis shows that they are implemented only for objects of simple geometric shapes — primitives. Proposed a method for automated layout, based on mathematical formalism of normal equations. The concept of objects normal equations was introduced by V.L. Rvachev. This article describes the original methods of normal equations building for both flat and tridimensional objects. It is shown that application of normal equations of objects being arranged allows you to create intelligent layout algorithms, reducing in terms of geometry the position problem of allocation of objects being arranged to the metric one. The paper shows additional options of objects normal equations for automated layout problems, such as equidistant object building. We display the problems that should be solved for a wide use of normal equations apparatus in automated layout practice. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pyshko A. P., Plotnikov A. Y., Sonko A. V., Frolov O. V., Eremin A. G., Zaritskii G. A. Methods of ensuring the radiation situation in the neighborhood of the lunar nuclear power station . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 58-66. The subject of research is a lunar base with nuclear power station (NPS) containing one or more thermoemission modules (TM). The purpose of current work is determination of the radiation situation in the neighborhood of the lunar NPS. The task of calculating radiation shielding (RS) in the neighborhood of the lunar NPS with one or four TM was solved for the implementation of this goal. The thermoemission nuclear power plant (NPP) with electric power of 50 kW was considered as TM. Calculation of radiation functionals was produced using the codes which allow to obtain a solution to the transport equation in two-dimensional (RAPID-KONT) and three-dimensional (MCNP) geometries. These codes implement two different methods of solution: a deterministic method and the Monte-Carlo method. Optimum profiles of RS layers were determined by using contribution currents and methods of optimal control theory (the Pontryagin maximum principle). The induced activity of the lunar soil and the fission products activity were calculated with the KAMOD-K code. The following variant of location of the reactor and RS in mine was sel ected as a result of designer research. The depth of the mine is to 3.7 m and the diameter is 1.41 m. The optimal mutual location of four NPS, substations and lunar base was received for sel ected variant of the TM placement. The total mass of communications between service module and each of the 6 TMs (two in a reserve) is ~2.1 t, the mass of communications between service module and the lunar base is ~0.4 t, the distance from service module to the lunar base is ~150 m. The radiation situation in the neighborhood of stopped NPS is mainly determined by the doze of gamma-radiation fr om the activation of the lunar soil. The dose of gamma radiation fr om the remaining activity of stopped reactor and the induced activation of the soil is reduced in 5 times by filling the mine by lunar soil. The obtained results can be used in manned lunar base designing. The number and capacity of each TM is determined by the needs of the consumers. Thus, it can be stated that the radiation situation in the neighborhood of NPS allows the personnel work at the lunar base and service module when TM is located in the mine. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gayvoronskii S. A., Ezangina T. A. The synthesis of the robust stabilization system of cable tension for the test bench of weightlessness simulation . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 67-74. The issue concerning the design of the stabilization system of cable tensionis being solved in the given work. On the basis of the conducted study and review of the similar systems the structure of the stabilization system of cable tension was suggested. This system is electromechanical two mass elastic flexible system with the interval parameters. The length of the cable and the mass of the apparatus under test are considered as theinterval parameters. For the given system the mathematical model was developed and the control and disturbance transfer functions were obtained. On the basis of the application of the robust approach to the synthesis of the system under consideration the methodology of the definition of the robust regulator adjustment ensuring the tolerable quality coefficient of the system operation at any values of its interval parameters was developed. The criterion of the maximum stability degree was used as one of the criteria of the robust regulator synthesis being the most relevant for the development of the system with unstable parameters. To apply the mentioned above criterion it is suggested to use the sufficient conditions of the specified stability degree of the interval system by the limitation on its oscillation and accuracy. The specified conditions can be represented as the inequality systems binding the interval coefficients of the characteristic polynomial and its coefficient quality indices (stability and oscillation parameters). From the obtained interval values those parameters are only chosen which ensure the maximum stability degree and minimum oscillation. To check and test the obtained results the areas of root locus of the interval characteristic polynomial are being constructed. The simulation modeling of the synthesized control system of cable tension in the Simulink package is carried out to assess the operability of the developed methodology of the synthesis of the robust regulator. The obtained transient characteristics under the worst modes of operations confirm the accuracy and validity of the selected solutions. Software was developed to put into practice the methodology of the synthesis of the robust regulator. This software allowsin on-line mode to make calculations of the desired parameters of the robust regulator with maximum stability degree of the system by its oscillation degree limitation. The results of the scientific investigation obtained in the given article can be used at aerospace industrial plants.
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Buyakas V. I., Dresvyannikov M. A., Zherikhina L. N., Tskhovrebov A. M. Schemes of counting of far IR photons in the context of problems of all-weather locating of distant space objects . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 75-86. In the context of problem of all-weather location of distant space objects four original detection schemes of far IR radiation, approaching by their sensibility to the level, allowing to use them in photon counting regime, are described.The first scheme is actually an upgrade of technique of the superheterodyne transfer of quantum fr om far IR to the visible range, wh ere photon counting is produced by a usual photomultiplier or APD (avalanche photodiode). The design of Up-converter considered assumes that nonlinear crystal-mixer is placed within the resonator of the single laser block. The second scheme of registration of far IR is based on directly biased light-emitting diode when the current is yet insufficient for radiation generation. Realized experiments allowed to observe photo response of such a system on radiation with energy below red edge of internal photoelectric effect. Two last schemes exploit cryogenics: in the first one far IR photon counting is assumed to perform using a number of desorbed helium atoms which are registered, and in the second — a number of unpaired spins in antiferromagnetic, the magnetic moment of which is measured by a SQUID. In both ways the effect has a nonbolometric character that provides speed sufficient for an application of such schemes in pulsed location systems. In the first case the nonbolometrisity of the effect is the consequence of stability of temperature value, corresponding to the first order phase transition, when all incoming power is spent not at material heating but exclusively on transforming the matter from one aggregation state into another. In the second case nonbolometrisity is achieved due to direct resonance action of far IR radiation on antiferromagnetic, resulting in flip-flop of spins and appearing of magnetic response registered by the quantum interferometer. In conclusion two possible registration schemes of near space small objects that do not use the location in ordinary sense are being considered: photographing in 10 µm range using a CdHgTe matrix and pulsed CO2 laser with transverse pumping (TEA ) as a megawatt flash; space gravi-exploration using the system SQUID-magnetostrictor, offered initially as an ultrasensitive gravitational wave detector.
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Ryabov P. A., Kalenskii S. M. Concepts of perspective hybrid mid-flight engines on gas and cryogenic fuels for aircraft . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 87-99. Prediction analysis of foreign and domestic studies shows that turbofan with high BPR and high cycle parameters using aviation kerosene will not provide meeting to environmental requirements for new aircraft already after 2035. And only hybrid gas-turbine engine (HGTE) using liquefied natural gas (LNG) allows developing aircrafts, meeting stringent emission standards up to 2045. The purpose of work is studies of available foreign and domestic research experience and generation rational concepts of HGTE using various fuel types, including gas and cryogenic fuels. According to purposes of the work following activities are conducted: — results of a foreign forecast of HGTE, conducted by Boeing and NASA, are analyzed; — perspective concepts of foreign power plants (PP) for aircrafts 2030 with HGTE having potential in improvement of cost and environmental characteristics are considered; — the key design parameters of foreign HGTE and results of researches on the assessment of their efficiency by the advanced aircrafts using kerosene and LNG as fuel are presented; — rational HGTE concepts are analyzed, numerical investigation of key design parameters of the mid-flight HGTE using different types of fuel, including gas and cryogenic fuels are performed. 2 most promising HGTE architectures based on the turbofan with high engine cycle parameters are defined in the paper. — Architecture HGTE-1 — usage of additional supply of fan shaft by mechanical power from electromotor (EM). Electrical energy to supply EM is generated by external source, i.e. power unit (PU) based on solid oxide fuel cells (SOFC). — Architecture HGTE-2 — usage of electrochemical generator (ECG) based on SOFC, operating in parallel with main combustor. Similar to HGTE-1 electricity, generated by ECG supplies EM, located on the fan shaft. Remaining heat generated by ECG supplies low pressure turbine. Various levels of power ratio between the low pressure turbine and EM, providing a fan drive are considered for each HGTE scheme. Design parameters of effective schemes of HGTE are specified. The forecast about prospects of development of considered concepts for 2030 and 2045 is made in the final part of the work. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vysotskii A. V., Alekseev D. N. Analysis of the effectiveness of the damping of resonance gear oscillations based on the dynamic contact problem by FEM . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 100-108. In modern conditions of engine manufacturing the high demands for quality, reliability and durability are produced to the accessory gearboxes that provide the basic systems of the engine and the aircraft. The design of the accessory gearboxes should ensure its efficiency over the entire range of engine operation, from startup to maximum mode during the entire flight, including the possible evolution of the airplane. In this regard, the design of gears in addition to providing strength characteristics of the gears is also necessary to eliminate the possibility of resonant oscillations in the operating range. If for some reason to get rid of the resonant modes is not possible, some special damping devices are used, limiting the resonance amplitude and stress level in the gear due to the work of the friction forces and the dissipation of energy fluctuations. Experience in the use of dampers in mechanical engineering is quite limited due to the complexity of the analytical evaluation of their effectiveness by traditional methods and difficulties in manufacturing. After the widespread introduction of numerical methods in the design of the gears in the 90 years of the 20th century the process of detuning was conducted much more accurate and efficient, and the direction of solution of resonance damping problems was weakly developed and now emerging techniques are in the making. Therefore, in response to emerging operational requirements in FSUE «SMC of GTE «Salut» on the basis of the finite element method (FEM) the method of estimation of efficiency of the damper in the conditions of occurrence of resonant gear oscillation was developed and tested. The main idea of the work is the realization of the possibility of the direct simulation of resonance oscillations of «gear-damper» system taking into account the friction on the surface of the contact interaction. The paper discusses the resonance vibrations of bevel gear with circular teeth for mode with two nodal diameters. To achieve this goal, it was decided several intermediate objectives: 1. Creation a physically correct model of dynamic loading gear with solution of the contact problem in the gearing (the definition of the contact patch change); 2. Creation a contact model of the «gear-damper» system, which is optimized in terms of accuracy and dimension to perform labor-intensive dynamic calculations; 3. Determination of the new value of the resonant frequency of the «gear-damper» system on the mode shape under consideration by solving a dynamic problem with a special impact force causing the damped oscillations of the system in the interesting mode shape; 4. Carrying out dynamic analysis of the «gear- damper» system with excitement in its resonant oscillations, as well as the selection of the axial mounting gap on a damper that provides the necessary down force, in which there is no increase in the amplitude of resonant vibrations. As a result of this work the new method was formed that allows to simulate the resonant vibrations of gears, to design and optimize various damping devices, preserving the amplitude of oscillation of the system to a safe level. Currently, the results of the implementation of the method was pilot-tested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Saganov E. B. Analysis of the stress-strain state of the torsion actuator made of shape memory alloy at the operating conditions in the course of the constrained deformation . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 109-116. The work is devoted to the theoretical modeling of the behavior of the torsional actuator with a working body made of shape memory alloy (SMA). Devices of this type are very promising for the use in the elements of mechanization of the wing, empennage, aircraft or missile control systems. In the frame of this work the problem of reverse martensitic transformation in the working body of the actuator with elastic counter-body, and fix condition for rods with solid circular cross-section made from SMA was solved. In both formulations of the problem with the heating rod made from SMA feels constrained deformation, the consequence of which is emergence of reactive stresses, which lead to an increase in torque. The analysis is performed in the framework of the non-linear model of straining of SMA in phase and structure transition in coupled formulation with the possibility of occurrence of the structural transition. It is believed that stresses in this process are small enough, so that plastic deformation not occurs. The influence of the stiffness of the counter-body on the thermomechanical response of the actuator is studied.The dependences of the dimensionless twist and torque from the dimensionless parameter of temperature, as well as diagrams of dimensionless stress for different stages of the heating rod are obtained. In this work it is established that in the process of heating the SMA actuator the bigger part of the cross-section rod is experiencing an increase in stresses. This requires to take into account the structural transition in solving problems of Reverse Phase Transformation (RPT) in the case of constrained deformation. The increase in the torque is a function of the stiffness of the counter-body and the torque, which active in case of Direct Phase transformation, and then the higher the torque then the greater the torsional stiffness has a counter-body. In the case of the RPT with fixed total deformations the phase deformations have transformed into an elastic deformation. This causes an increase in stress and torque. The maximum level of stress and torque at the end of the RPT is higher than the similar values for RPT with counter-body. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolaev Y. L., Chernova A. V. Magnetic testing selectivity improving by vibration-induction method . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 117-121. Implementation of gradiometry techniques for magnetic fields registration in the process of objects surface scanning is an effective approach to magnetic testing selectivity improving. We suggest vibratory inductive method based on induction transducer which sensitivity depends on the rate of change magnetic flux, coupled with turns of its inductance coil. When vibrating coil moves along the surface under testing the first sign of blemish presence will be indicated by the first harmonic amplitude surge in the spectrum of induced electromotive force signal. With further movement of the coil towards the defect center a signal, representing a superposition of harmonics with frequencies ω0 and 2ω0, appears, with the tendency of increase in second harmonic amplitude and decrease in that of the first one. This is the second sign of a blemish presence. When the coil central section coincides with the center of fault stray magnetic field, the induced signal contains only second harmonic, which amplitude assumes the highest value. This is the third and the main sign of a blemish presence. It has a selective value with locality of flaw location. In case of normal component testing circuit, the sign of blemish presence is revealed by a surge in the first harmonic amplitude over the fault surface. The presented experimental data has been obtained through defected samples testing with a research facility, providing test sample movement against induction transducer according to three coordinates with resolution of 5 microns, as well as relative change of the transducer and test sample angular location. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsov D. A., Turchenko I. S. A design methodology of controllable inductors for new generation of aviation rectifying units. Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 122-131. Regulated rectifying units are the key functional units of power supply systems for different types of modern aircrafts. At present thyristor and transistor controlled rectifiers are used on board an aircraft. However it should be noted that magnetic switches (MSs) preceded implementation of semiconductor switches used for electric power regulation and stabilization. Highly efficient soft magnetic alloys development allows reconsideration of MSs energy and size efficiency indexes as well as their functional area spectrum. The relevance of such class of devices studying is clearly indicated by the facts of their mentioning in foreign scientific and technical publications. The foreign sources discuss design and implementation problems of such devices for modern and competitive aircraft power supply systems. Special emphasis is made on application of advanced soft magnetic amorphous and nanocrystalline alloys for cores of MSs, which leads to a significant improvement of their electromagnetic properties. New converter unit based on such magnetic switches is able to preserve the best features of its traditional prototype predecessor, in comparison with thyristor and transistor competitors, such as: ease of implementation; higher reliability; better electromagnetic compatibility; resistibility to special factors effect. The authors have proposed new structures of aviation magnetic-regulated rectifying units (MRRUs), based on controllable single-winding saturable inductors based on modern amorphous (or nanocrystalline) alloys cores with rectangular hysteresis loop. At present, there are no publications concerning engineering philosophy and design methods for this class of devices. Thus, the authors consider it expedient to offer their own methodology of design and estimation of controllable single-winding saturable inductors for proposed new MRRU structures. The proposed method is universal and broad-based for transformer and transformer-less single-phase and multi-phase rectifiers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karasev D. A., Arutyunov A. G., Zagordan A. A. Development of cargo aircrafts with electric power plants . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 132-139. We have investigated the levels of specific batteries (AKB) characteristics, which assure both the technical and economic feasibility of a cargo aircraft with electric propulsion system development. The calculation of the characteristics of electric cargo aircraft was based on the following assumptions:
The dependences of the aircraft takeoff weight from the specific energy density of the battery and the relative masses of the onboard battery for a number of payloads and ranges are shown in tables 1.2.
Table 1. The cost of charging the onboard battery to deliver 20 tons of cargo to a range of 5,500 km electric aircraft
Table 2. The cost of charging the onboard battery to deliver 100 tons of cargo to a range of 9000 miles electric aircraft
The development of the mainline aircraft powered with electric power plant based on high-capacity batteries is technically feasible with the level of specific energy of on-board battery at about 4.5 — 5 kWh/kg (the maximum takeoff weight of the aircraft will exceed the takeoff weight of an analogue powered with conventional power plant by not more than 1.5 times, and aircraft performance will be identical). Upon achieving the energy density of on-board batteries over 6-6.5 kW·h/kg, the takeoff weight of the aircraft with electric propulsion system becomes lower than the takeoff weight of the aircraft fueled with hydrocarbon fuels. Economic efficiency of applying the electric propulsion system in transport aviation primarily depends on the cost of the battery and its service life. By achieving cost-efficient service life utilization of ultra-battery at a level of 1.5-3 times lower than modern lithium-ion batteries demonstrate, the use of all-electric cargo aircraft will be economically feasible. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Nikolenko T. Y. Features financing of innovative projects in the aviation enterprise . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 140-148. In the formation of innovative economy the scientific-technical progress, information technology, wide dissemination and use of innovations become the main factors of socio-economic development. Innovation is an integral feature of the modern economy. Innovation involves a large degree of risk and lack of complete assurance of success. Thus, particular importance is the study of projects of innovation, which depends on the reasonableness of the expert evaluations. Under current conditions the research question is the impact of expert assessment on the decision of investors to finance innovative projects in the aviation industry. This article defines the essence and technology of expert assessments of innovation risk, and also considers the problem of the influence of expert assessments for decision-making on the financing of innovation project of the aviation enterprise. It includes an example of a risk assessment of innovative technologies for linear friction welding at JSC «Ufa engine industrial Association». It simulates an option of getting the opposite results. It is proved that expert assessment of innovative project is subjective. The main conclusions are that the important stage is the selection of the expert group, so as to obtain the most equitable assessments the maximum possible number of experts related to the sector should be used. They should represent different professional fields (engineers, of self-esteem experts is too subjective, and the results may be significantly overstated. It makes sense to use the evaluation of the professional level of experts by engaging outside experts, or by means of tests. Initial information about an innovative project should be accurate and reliable at the time of assessment. Taking into account all possible risks requires the great awareness of external and internal factors influencing the innovation process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rychagov M. S. Methodical approach to ensure the economic security of small aircraft manufacture . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 149-154. Development of small aircraft in Russia is possible with performing a wide range of tasks in interests of national economy, namely: development and production of inexpensive, highly effective, multipurpose light planes of passenger capacity categories, and large-scale production and a mass market launch of inexpensive, highly effective, multipurpose small aircraft with performances, operation cost, quality, safety and service guarantees for the purpose to replace the park of the outdated aircraft equipment and increase the level of small aircraft development. The analysis of the development main directions of the small aircraft manufacture has to be directed on the solution to the following tasks: modernization of the existing park of the aircrafts (A) of small aircraft; mass production of planes of small aircraft; restoration and development of competences of the Russian aviation industry in the field of development of easy A; development of system of ensuring financial, technical and technological, personnel safety of the A manufacturing enterprises of small aircraft; organization of effective system of economic security of support for the production of Russian small aircraft; stimulation of demand for services of the airlines operating in the market of local air transportation. The integrated approach to increase the level of economic security of small aircraft production has to include the analysis of the following directions: analysis of production specific; creation of criteria, indicators and their threshold values, and also the mechanism of providing economic security within state regulation of activity of the manufacturing enterprises of the aircraft equipment to formulate the organizational and methodical bases for formation of functional components of economic security of the enterprises. For an assessment of economic security of the small aircraft manufacturing enterprises it is necessary to construct the model, which will provide the possibility for determination of economic security criterion value for the production of small aircraft. For creation of such model it is necessary to construct system of the indicators describing the analyzed object, considering not only the internal, but also external factors, for example, the structure and nature of changes in a domestic and foreign market, instability of an economic and political situation and others. For an assessment of economic security condition of small aircraft production it is offered to use a complex of actions for prevention of threats within the offered methodical approach: — it is necessary to make definition of system of indicators of economic security and their group on the main functional components; — on the basis of the analysis and statistical data with the help of modern economic-mathematical methods it is necessary to estimate expected value of criterion of economic security of production of VS of small aircraft; — to develop a complex of actions for prevention of the possible predicted threats; — to make a complex assessment of current state of economic security of small aircraft production, which will allow to estimate quality of the developed package of measures and to consider possible mistakes and miscalculations for further planning. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ryabchenko A. V. «Trinity» of the functioning principles of hi-tech corporations on the example of the integrated structures of the space-rocket industry . Aerospace MAI Journal, 2015, vol. 22, no 1, pp. 155-165. Quality of the organizational and economic mechanism is characterized by functioning efficiency of the integrated structures of the space-rocket industry, consisting in ensuring life cycle of the created missile and space equipment. In the existing realities the need for improvement of the organizational and economic mechanism which methodological basis will be made by the principles of functioning of the integrated structures of the space-rocket industry is actual. Formation of a complex system of the principles is possibly at the accounting of a current state and tendencies of development of the space-rocket industry, features of activity of the integrated structures and qualifying standards to organizational economical mechanism of functioning. In the present work the three types of the principles that gives the chance to establish «trinity» of the principles of functioning of the integrated structures of the space-rocket industry are allocated. The first type — the principles of functioning of the integrated structures as hi-tech organizations: efficiency of functioning, continuity of the basic principles of the organization of production, subject and technological uniformity of the made production, compliance of the structural organization of corporation to object of production, a multi-nomenclature at single and small-scale type of production, stability of functioning of the enterprises entering association, unity of all stages of life cycle of the missile and space equipment. The second type — the principles of the structural organization of branch corporations: hierarchy, openness, stability, adaptability, interaction, management, proportionality, balance. The third type — the all-system principles: integrity, purpose, variety, complexity. The established «trinity» of the principles could make a methodical basis for reorganization and improvement of the organizational and economic mechanism of functioning of the integrated structures of the space- rocket industry.
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Grishanina T. V., Shklyarchuk F. N. Deformation and aerodynamic characteristics of a membrane wing airfoil in subsonic flow. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 7-12. In this work a membrane wing of large aspect ratio in subsonic flow is considered. The wing consists of the front thin-walled beam and the rear beam connected in some transverse sections by ribs and by presstressed plane membranes located between the ribs. To calculate the deformed shape and aerodynamic characteristics of the wing we consider the plane problem for the wing airfoil. The aerodynamic pressure acting on the deformed airfoil in subsonic flow is determined by using the exact solution in the series. The finite element method (FEM) is used to determine the small membrane deflections. The coupled problem of airfoil aeroelasticity is described by the system of linear algebraic equations for the node displacement of the FE-model. Solving this system we find the distribution of the aerodynamic pressure and the aerodynamic coefficients for the airfoil lift and moment. Besides these we find the boundary of the membrane divergence when the membrane turns up. The example of the membrane airfoil is considered for which the numerical results are obtained in terms of the nondimentional parameter representing the ratio of the kinetic energy head to the membrane tension. Regulating the membrane tension by changing the rib lengths makes possible to control the aerodynamic characteristics of the airfoil and the wing on the whole without moveable aerodynamic control surfaces. The results of this research can be used in design of the superlight high altitude unmanned aeroplanes with large duration of the flight. The proposed method of the solution to a new aeroelasticity problem is original and the obtained results coincide with the exact solution in the particular case of the rigid airfoil. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eskin V. I., Poluektov S. P., Rubinov V. I., Kin K. L., Afanasev A. S. The investigation of pitot-static tubes accuracy characteristics by means of airflow pattern mathematical modeling. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 19-26. The presented research is focused on the mathematical models of instruments, which are used to measure the altitude and speed parameters of modern aircraft. The paper aims to investigate the possibility of increasing the accuracy of altitude and speed measurement during the highly maneuverable aircraft flight while solving the problem of perception of the total incoming air pressure. The presented research is relevant due to the constant increase of the requirements for the accuracy of the altitude and speed parameter measurement during the flight. This increase arises from the necessity of ensuring the high level of flight safety and effective fulfillment of combat aircraft system missions. The matter point of the problem of accurate in-flight altitude and speed measurement consists in the following: various factors influence the initial parameters (pitot and static pressure, angle of attack and sideslip), which are measured directly with the appropriate on-board aircraft sensors. Multiple factors contribute to the total error of the primary airflow data perception. Among these the aerodynamic measurement error contributes the most. Therefore, the task of aerodynamic error reduction is relevant. The paper contains the solution of the abovementioned task for the pitot pressure instrumentation channel. The SolidWorks and ANSYS software systems were used for simulation modeling. As a result the accuracy characteristics of the pitot pressure instrumentation channels of various pitot-static tubes were obtained. The characteristics were obtained at airflow Mach values ranging from 0,2 up to 2,2 for the angles of attack from 0 up to 30 degrees. The simulation was conducted for a standard pitot-static tube and several examples of various developed configurations. The paper adduces the results of the comparative analysis of standard and developed pitot-static tubes. After that the design modifications of the nose part of the developed pitot-static tube are substantiated. The obtained results allow the authors to recommend conducting further research and tests of the proposed pitot-static tube model, which is equipped with a pitot pressure instrumentation channel that provides enhanced measurement accuracy. The implementation of the proposed design modifications of the on-board pitot- static tube would allow to determine the aircraft altitude and speed parameters with high accuracy for a wide range of speed and angle of attack values. This ability is especially important for highly maneuverable aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pravidlo M. N., Korizhin O. V. The method of calculation of the interferential aerodynamic characteristics of stores, which are separated from the aircraft. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 13-18. The development of the effective aviation armament system is one of the important issues that arise during the design of new and modernization of the existing military aircraft. In addition to weapon control system, sighting systems, etc. the aviation armament system includes the weapon launchers with the munitions that are installed on them. A multitude of technical decisions, which are aimed at the safe separation of the munitions from the delivery aircraft, is implemented to provide for the usage of aviation weapons. In general the safe separation refers to fulfilling the following requirements during the store flight in the vicinity of the delivery aircraft after its release from the launcher:
- separation of the store from the airplane without its collision with the airplane itself, its structural elements or stores, which are installed on the adjacent suspension points;
- retention of the store spatial stability during its flight after the separation from the aircraft (for stores with a control and targeting system);
- absence of thermodynamic impact from the exhaust jet of the store engine on the functioning of the airplane propulsion system, airplane structural elements and other stores that are installed on it. Technical decisions of integrated nature are required to provide for the munitions release. Such decisions define the essential parameters of all objects that make up the munitions separation system, namely, the «delivery aircraft — launcher — munition» system. These parameters include the following [2]: 1) for the delivery aircraft: linear and angular coordinates of the store in transport position; 2) for the weapon launcher: the increments of the linear and angular coordinates and velocities of the store, which take place during its movement on the launcher; 3) for the controlled stores: configuration and settings of the stabilization system during the flight in the vicinity of the delivery aircraft; the preliminary deflections of the tales and the overload during the initial movement of the store away from the delivery airplane (the values of these parameters are assigned by the control system after the store separation from the launcher). Violation of the boundary values of the above- mentioned groups of parameters can result in aircraft or store damage, which may cause an accident or store mission failure. The separated store may become unstable, which can lead to mission failure or collision with other stores (during the separation of several stores) or adjacent airplanes of the operations group. Technical decisions, which are aimed at providing for the usage of aviation weapons, are checked with the help of simulation of the store launch and subsequent analysis of store spatial movement in the vicinity of the delivery airplane. At that an important role is played by the reliability of interferential aerodynamic characteristics of the store-airplane system in the vicinity of the delivery airplane and characteristics of the isolated separated store. Interferential characteristics in transport position and in the aircraft vicinity generally depend on a wide range of parameters such as: - the position of the store relative to the airplane linear and angular coordinates of the relative store position; - the variant of munitions installation NI, the presence of suspended loads on adjacent stations or the proximity of the aircraft structure; - the aircraft angles of attack and sideslip â during the store launch; - speed and altitude of aircraft flight, which is represented by Mach number M. The dependence of the interferential coefficients can be formally represented by the following function: Thus the problem of determination of the interferential characteristics of the cargo-airplane system is multifactorial and includes all of the following: the design parameters, the location of the load on the airplane, the environmental parameters, the altitude and speed of airplane flight. The described method allows the designers to determine the interferential aerodynamic characteristics of the delivery airplanes and stores of various shapes at early development stages without conducting the wind tunnel experiments. This can reduce the cost of wind tunnel tests and time, which is required for the optimization of the store aerodynamic configuration and its placement on the airplane, significantly. The results, which were obtained by using the described method, can be used to calculate the parameters of separation of loads from the aircraft and separation safety evaluation. The data, which was processed by using multidimensional (multivariate) interpolation, allows the researcher to analyze the interpolated dependencies based on all the factors that influence the interferential coefficient values. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Boshlyakov A. A., Ovciankin G. I., Rusheva D. V. Active 3 dimensional stabilization system of photo and video equipment for unmaned aircraft. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 27-36. Lately a lot of popularity gained unmanned aircraft vehicles (UAV) for research current situation on the ground from the air. Simultaneously, the increased requirements for the quality of the image obtained with a camera mounted on the UAV. It is necessary to ensure offset images are not more than 1/3 pixel. As a consequence to the fore extends the problem of vibration damping obtained from the engines of the aircraft. To ensure high quality video it is necessary to extinguish the three-dimensional angular camera shake amplitude of units of angular minutes and tens of hertz frequency. Currently the most widely used two basic ways to solve this problem, applicable to aircraft: gyro stabilization and electromechanical systems. Options considered to have a not satisfactory characteristic of weight and size, or the high cost. The purpose of this work is to construct a three-dimensional stabilization system that provides vibration damping of aircraft body. Proposed a new approach to the construction of the stabilization system of the camera. This system is constructed on the basis of the mechanism of parallel kinematics (hexapod) that allows to get high precision system at its small sizes. Developed a mathematical model of a 3-dimensional stabilization system based on hexapod and solved the inverse problem of kinematics. Simulation in Matlab allowed to obtain requirements for the hexapod actuators. Analysis of different types of drives has shown that necessary characteristics have actuators built on piezo actuators. Their distinctive feature is the low weight, great efforts on the output, high speed of working off control signals. In this work was developed a mathematical model of piezo actuators that takes into account the following parameters: the total weight of the reduced mobility, the coefficient of elasticity coefficient of the inverse piezoelectric effect, the ratio of direct piezoelectric effect, the damping coefficient, the electric capacity, the internal resistance of the source of emf. Mathematical modeling shown the possibility of using the piezo actuators in 3-dimensional stabilization system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Darnopykh V. V., Malyshev V. V., Usovik I. V. Multi-criteria optimization of efficiency of earth remote sensing systems constellations target functioning on the basis of operative planning. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 37-52. Modern projects of Earth remote sensing systems (ERSS) provide combination of their target functionality for solution to a range of special tasks. That is why the spacecraft (SC) is designed as multi-purpose one and ERSS is also considered as multi-purpose. Therefore the problem of planning SC multi-purpose orbital constellation target functioning is multi-criterion. So, it is required to carry out at the same time solving of ERSS target functioning efficiency for several various criteria (or for one of the most preferable from them). The solving of such complex optimization problem is possible only during the development and application of specially designed methods for complex multi-criteria optimization adapted for multi-purpose ERSS functioning. The main local and integrated indicators of ERSS target functioning efficiency such as operational efficiency of shooting information broadcast from SC on-board to ground stations, average daily volume of the shooting information broadcasted from SC to ground stations, frequency of Earth equator observation, the cumulative value of shooting information are considered in the article. The general optimization problem statement for multi-criteria optimization of ERSS target functioning efficiency on the basis of operative planning is given in the article with the using of mathematical models and similar optimization tasks formalization presented in earlier authors publications. The examples of solution to analysis and optimization model tasks operative planning of target functioning for ERSS constellations including from 1 to 5 SC with the project parameters «Resource», «Kanopus», «Meteor» are presented in the article. The results of the comparative analysis of target functioning of these constellations are presented as well. The results of multi-criteria optimization are given in ratio on different coefficients of importance of integrated indicators of ERSS target functioning efficiency. The corresponding recommendations about a choice of the ERSS constellations are formulated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Barabanov A. A., Vyatlev P. A., Sergeev D. V., Sysoev V. K. Circuit analysis of laser perforation of metallized polymer films of screen-vacuum thermal insulation. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 53-61. As screens of SVHI it is used the polyethylene terephthalate or polyimide film metallized with aluminum on one or both sides by the film thickness of 5-20 microns, the aluminum coating layer is 0.1 micron. Outer and inner surfaces of SVHI are sheathed by combined materials «Nyika-KPMA» or «Nyika- PAM-2» with a thickness of 150 microns. To ensure evacuation and protection against electrostatic charges the films of SVHI are perforated by holes 2-5 mm with perforation pitch from 10 × 10 to 50 × 50 mm. Laser perforation of SVHI films in comparison with other methods has a number of advantages: significantly increased productivity, increased accuracy of perforation. Presented method allows to quickly adjust the diameter and pitch of holes. Jobs created by the laser system is based on the application of the principle of linear-angular scanning of the laser radiation, in which the movement is carried out by the laser beam on the surface of the material being processed. The principle of the system is realized through the use of linear angular scans, which consists of: - Fiber laser (YLP-1-100-20-20-RG);- Linear actuator LSM-P-32-265-50; - Optical module angular scanning. Laser perforation system can operate in one of two modes of perforation: - Laser perforation is simultaneously with continuous movement of the film;- Laser perforation in the start — stop mode is carried out on a stationary film. Calculations of the motion path of the laser beam in the scanning system and the estimation of the effect of errors on the accuracy of the process of perforation at various modes of perforation are carried out. Comparing the hole-cutting mode it can be concluded that the start-stop mode provides a greater accuracy than by cutting apertures on a continuously moving film. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vishnyakov V. M., Lebedenko V. P. Use of laser target equipment on board of missions to asteroids. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 62-72. In the carried-out and planned missions of the spacecrafts (SС) to the Near-Earth asteroids (NEA) and other small space objects the laser devices are often applied. However, the range of tasks solved by them is usually limited by distance measurement at small ranges and precise height measurements during landing to NEA. At the same time, the use of multipurpose laser equipment onboard SC allow to avoid failures and violations of processes of approach and landing to an asteroid (like it was, for example, during the landing of SC «Hayabusa» to asteroid «Itokava»), obtain various data on structure of a surface and substances of asteroid. Here is a preposition on laser target equipment based on multi-functional 3D-lidar intended to be used on board of satellite missions to near-earth asteroids and other small space objects. 3D-lidar possible functions are as follows: precision range and velocity measurements, three-dimensional monitoring of asteroid shape and surface structure, precise descend of a lander, 3Dmonitoring of asteroid impact results, laser spectroscopy of substances of a space object, etc. The lidar makes continuous measurements of the current range and radial velocity at all distances between SC and NEA. At small (some kilometers and closer) distances the lidar allows to receive detailed spatial «portrait» of object due to application of a threedimensional photosensitive matrix. Process of satellite approach with NEA becomes complicated due to large (tens or hundreds kilometers and more) errors of preliminary data of NEA orbit parameters received from ground-based observation facilities. In case of use of onboard SC of the «rough» distance-measuring instrument (for example, an optical direction finder or TV-camera) there will be a big uncertainty of knowledge of proper distance to NEA. It can lead to excessive costs of propulsion system fuel for operations of approach and landing to NEA. Calculations of necessary liquid rocket fuel expenses of the satellite propulsion system during approach to NEA have been carried out. It is been shown that using an onboard laser rangefinder would allow to reduce fuel expenses approximately twice in comparison with use of only passive onboard observation systems. It is also shown that during tests of deflection means of NEA from a trajectory dangerous to Earth the lidar can measure very small (up to 1...5 mm/sec) additional increments of the speed received by asteroid in the result of collision with the special SC-impactor. Use of a multipurpose lidar may lead to some increase of satellite overall mass; nevertheless, it is quite compensated by increase of amount of the tasks solved by the onboard equipment and accuracy of their performance. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. Optimal modular dimension-type series of power plants with aluminum as an energy source. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 73-79. Analysis of the aerospace engineering needs and other modern self-contained technical facilities has shown that the aluminium-air (AA) mechanically rechargeable chemical current sources (CCS) can be effectively used as the main energy sources or emergency power systems. This paper helps to solve an actual issue as the developing of the functional dimension-type series of AA CCS. All power plants gathered into one series via their characteristics (so called parametric series) are developed fr om one point of view. The modular parametric range assumes that all power plants are built by means of consecutive or parallel commutation of the basic modules. As the optimization parameter for the modular parametric range of AA CCS the electrode sizes were accepted, namely the size of the gas-diffusion oxygen cathode. The cathode usually has high over potential and its operation time lim it the operation time of the AA CCS due to its structure. The evaluations of the different parameters of the modular range were also carried out in this paper. It is also shown that in the cases of difficult power consumption usually characterized by the cyclic higher power peaks the hybrid scheme of the power plant can be effective. Such scheme includes AA CCS and buffer accumulator battery (AB), for instance nickel metal hydride or lithium-ion batteries. AA CCS provides a basic power rate and recharges the AB, but AB covers the power peaks if it is necessary. The evaluation of the required basic modules numbers has done and it is shown that the main factor which limiting the power rate of the basic modules is maximum achievable level of the one cell in the AA battery. This is determined by the technological limits of the large-area gas-diffusion cathodes production and the possibility to provide the proper conditions of the thermo- and mass exchanges. This paper shows that based on the chosen optimal parameters it is possible to make 2-3 modulardimension-type series based on the 3-5 basic modules in each series. Besides, the basic module can include 1-6 or 1-8 battery depending on its power rate. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zuyev Y. V., Istomin Е. А., Lepeshinskii I. A., Reshetnikov V. A., Chabanov V. A. System of the laser measurements by particulate composition for two-phase flows. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 80-87. Issues related to measurement of particle size distribution of two-phase flow in the mixing devices of the combustion chambers of the air-jet engine by laser-optical methods are considered. Special attention is paid to the solution of problems that arise when a large distance to the measuring volume and polydispersed composition of the liquid phase. This is due to the fact that when working with real fuels, such as kerosene, it is necessary measuring equipment to remove possible distance, and the droplet size of the fuel in the combustion chambers, as a rule, vary widely. The block diagram and design of a laser measurement system are considered. In the operation of the ring photodetectors, which are typically used in laser measuring sizes of particles, is replaced by a matrix of a digital camera. This allows you to create a system where the laser and reception optics do not have a rigid connection which is important in conditions of full-scale experiment. In this case center of diffraction pattern of each frame is set programmatically. The multiple times photographic registration of two-phase flow following by a specially designed procedure «stitching» frames is used to increase the dynamic range of the measurements . Also to improve the measurement accuracy characteristic curve of the matrix a digital camera is based, by which means is determined by the intensity registered by the matrix of light. It is shown that the using installed in the focal plane of the Fourier lens the additional light-diffusing screen allows you to extend the range of the measured particle size and to simplify the optical system of registration. In this case telephoto Fourier lens of large diameter were used to work at greater distances (in our experiments we used a lens with a focal length of 500 mm light diameter of 195 mm). A light-diffusing screen was made from sandblasted on one side of the glass by thickness of 3 mm and size 300 mm. The block diagram and design system, laser measurement of dispersion of two-phase flows, which was used in full-scale tests are considered To improve the reliability of the measurements and to expend a measuring range, the emitter unit contains two laser emitters — red (wavelength 650 nm, type KLM-650/20) and green (532 nm, KLM 532-30-5). Depending on the set before the experimenter tasks possibly using different algorithms for processing the received scattering indicatrixes. To assess the validity of the results obtained by using the system of laser measurements of particle size, comparative experiments with analyzer of particle size the firm Malvern were carried out The distance to the test object of research the analyzer Malvern was 4 times less. The comparison showed that the differences do not exceed 8%. Also the results obtained in the experimental study of the mixer on a working body air-water with the formation of gas-droplet stream are presented. It was found that the investigated mixer with increasing gas flow rate at constant liquid flow rate Sauter mean diameter of the droplets is reduced from 140 to 90 ?m. At a constant concentration of the liquid phase and the increase of flow rate from 1.5 to 2.25 kg/s, there is a minimum in diameter which is in the area of consumption of 2 kg/s. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ismagilov F. R., Khayrullin I. H., Vavilov V. E., Yakpov A. M., Bekuzin V. I. The use of non-contact bearings in aircraft. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 88-100. One of the major complex problems facing modern aircraft manufacturers is to increase energy efficiency, fuel efficiency and environmental performance of aircraft (PA), with an increase in their performance and expansion capability solved PA. To partially solve this problem in PA used and planned to use contactless bearing supports (CBC) that increase the speed of equipment aircraft, its environmental friendliness and reliability, while reducing the weight and dimensions. From the analysis of works of Russian and foreign authors can conclude that in the elements and nodes of the aircraft used several types of CBC: - Aerodynamic bearings;- Air bearings; - Active magnetic bearings; - Hybrid magnetic bearings. Table shows a comparison of the considered types of criterial CBC considering the application (aviation industry). Table shows that the most promising type of non- contact bearings, to provide a reliable and efficient operation of the equipment of the aircraft, as well as provide the ability to integrate non-contact bearings in gas turbine aircraft engine is a hybrid magnetic bearings. In order to increase the effectiveness of their use in aircraft is necessary to solve a number of problems, such as an increase in the operating temperature of high-coercivity permanent magnets, the creation is not sensitive to the temperature of sensorless control methods rotor position, it is necessary to expand research on the development of high-temperature insulation materials, as well as to produce a study on control system synthesis capabilities hybrid magnetic bearings, and aircraft systems. Comparative analysisof gas bearings and hybrid magnetic bearings In addition, there are a number of unsolved theoretical problems of research of hybrid magnetic bearings, for example, there is no uniform classification of their design concepts and designs, etc. In other words, for the successful implementation of programs more electric aircraft, it is necessary to extend the common theoretical base on hybrid magnetic bearings. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nazarov V. P., Yatsunenko V. G., Kolomentsev A. I. Constructive and technological factors of stability of energy parameters in turbopump assemblies of rocket engines. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 101-105. The level of operational and technical characteristics of propulsion systems in modern aircrafts is determined by a combination of functional, technological and economic indicators providing high quality of aerospace industry items. There are some features in use of rocket engines as part of carrier rockets and spacecrafts which stipulate increased demands to the reliability of all its structural elements and the engine as a whole. One of the main indicators of rocket engines quality and reliability is a stability of energy parameters in high- speed centrifugal pumps of fuel liquid components supply system. In engine production it is controlled by the results of modeling hydrodynamic pumps testing and assessment of energy parameters dispersion (head and efficiency) in comparison with their values set by design documentation. In general case deviation of functional parameter in complicated hydraulic system is determined by an error of every influencing element, values of influence coefficients and error spreading character. For high-energy pumps any hydrodynamic parameter deviation is stipulated by influence of deviations in geometric dimensions of details in flow section, deviations of details mutual position because of error in pump assembling process, errors of measuring equipment during tests and maintenance of a given test regime. Analyzing the results of pumps tests it is obvious that the task of energy parameters stabilization can be solved by increasing of manufacturing accuracy of hydraulic path details, decreasing of errors in pump assembling process, raising measuring accuracy and calculation of the controlled parameters in units tests. Experimental studies of specific investment of constructive and technological factors into the energy parameters deviation were conducted by standardization method when the pointed value of controlled parameter was result of handling from 9 to 27 attempts that allowed significantly increase the experiment veracity. Experimental and analytical researches, calculation of coefficients of constructive and technological factors influence are made for pumps with closed centrifugal wheels. As a result of analytical and experimental researches it is developed a calculation method of head and efficiency deviations, considering the influence of constructive and technological factors into the energy parameters stability of centrifugal pumps. Solving of this task promotes to the creation of high quality rocket engines with set level of reliability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Knyazeva V. V., Chubarov O. U., Neretin E. S. Fault conditions diagnostic technique for firing trials based on controlled parameters measurements. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 106-115. The goal if this work is functionality enhancement and software and hardware development for liquid thruster firing trials software and hardware complex based on algorithmic and hardware development for automated information and measuring and controlling systems (IM&CS) with the possibility of fault conditions functional diagnostics during liquid thruster continuous running. Designed automated firing trials IM&CS allows testing of the existing and emerging liquid thrusters operating on ecologically clean propellant components and uses the function testing methods of faulty states during liquid thruster continuous running to determine emerging failures. The applied methods are based on complex systems mathematical modeling and simulation methods, theory of measuring and measuring transducers, function tests theory, experimental research as well as bench trial and full-scale tests methods. The developed fault conditions function tests technique uses fault condition classes as well as secondary features selected as fault characteristics. Fault conditions of each class causing new static mode of the thruster are c encoded by selected secondary features. The developed algorithms realizing the developed technique together with fault diagnostics algorithm allow assigning lined-up faulty condition to a certain class or classes in order to determine a failed sensory element or elements. We realized these algorithms in the form of software «Liquid Thrusters Fault Conditions Diagnostic Module». To develop the software we use Delphi package of Embarcadero RAD Studio XE. Using the developed automated IM&CS included into thruster firing trials software and hardware complex we carried out tests of such thrusters as DMT MAI 202 operating on kerosene and oxygen (g); as well as thrusters DMT MAI-200-1P DMT MAI-200-7P DMT MAI-500VPVK operating on high-concentration hydric dioxide (HCHD 98%) and kerosene. We also carried out first stage tests related to developing prospective liquid thrusters operating on clear propellant components. Implementation of suggested algorithms allows expansion of firing trials software and hardware thrusters in the pipeline and prospective ones. We carried out more than 400 experiments to test the developed software. These experiments fully confirmed its functionality with respect to fault conditions function tests. The adequacy of the developed techniques and algorithms applied to fault conditions diagnostic subsystem for liquid thrusters in continuous running was fully confirmed in the course of liquid DMT MAI 200 thruster firing trials when fault conditions occurred. Application of the developed IM&CS with the possibility of functional diagnostics of the liquid thrusters faulty states in continuous running allowed to reduce the amount of fire tests by 9% for DMT MAI 200 thruster development and studying. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Velichko A. P. Development of ground-based remote monitoring of the atmosphere. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 116-123. In this paper we report on engineering of the automated ground-basedsystem for the measurement and control of meteoparameters of the atmosphere. Improvement of the existing hardware complexes and invention of the new automated gages on modern element base is the most perspective direction in meteorological instrument making. Applying the considered gages it is possible to receive the following characteristics of controlled meteoobject in real time: height and temperature of the lower bound of overcast, water content, water stock and some other characteristics of clouds; temperature, pressure, humidity of air and parameters of a wind in a ground layer of the atmosphere; optical thickness of the atmosphere; coefficients of blackness of clouds of various form; assessment of transparency of the atmosphere; optical density of translucent clouds; density of a ground aerosol and sizes of its particles. Measuring systems are united spatially and functionally in the NALRK general complex. This complex includes the following measuring systems: - the scanning infrared installation intended for determination of the main meteoparameters of the atmosphere and clouds; works in the spectral range of 8-14 microns; - infrared pulse lidar for determination of height of the lower bound of clouds; the maximum range of action to 7,5 km works at wavelength ? = 1,06 microns; - lidar with the linear frequency modulation (LFM) for measurement of an aerosol in a ground layer; sounding height to 1 km works at wavelength ? = 0,532 microns; - the watching infrared installation for determination of optical density and thickness of translucent clouds, and also coefficient of transparency of the atmosphere; working spectral range is from 2,1 to 2,4 microns, the tracking mode the automatic; - the laser measuring instrument of the sizes, concentration and speeds of particles for determination of parameters of a ground aerosol; the measured range ot1 to 300 microns; - a meteorological station for determination of the main meteoparameters of a ground layer.
Use of the ground-based automated lidar-radiometric complexwithresults of measurement will be expedient in TsAO of Roshydromet, RCfor Earth Operative Monitoring of Federal Space Agency, MNPO «Spektr», GPU «Mosekomonitoring», IFA n.a. A.M. Obukhov of the Russian Academy of Sciences, GGO n.a A.I. Voeykov and in other organizations connected with research and forecasting of a meteorological situation, and also with environmental monitoring in any region. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalev K. L., Penkin V. T., Modestov K. A., Dubenskii A. A. Characteristics of superconducting synchronous generators with claw-shaped poles for aircraft. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 124-128. This paper is devoted to onboard brushless superconducting synchronous generators for full-electric aircraft. The new constructive scheme of superconducting synchronous machine is offered that contains claw-shaped poles and permanent magnets. The advantages of suggested constructive scheme of the machine are specified. It is shown the permanent magnets in a claw-shaped rotor increase main magnetic flux in an active zone of the generator. The purpose of work is to get characteristics of machine and recommendations for choice of constructive data of machines on the basis of the obtained characteristics for further projecting. Open-circuit characteristics and on-load characteristics of the offered synchronous machine with claw-shaped poles and permanent magnets obtained settlement and by practical consideration and reflecting advantages of application of permanent magnets in the offered design are provided. The obtained open-circuit characteristics confirm expediency of application of permanent magnets in claw-shaped rotor. On the basis of the obtained family of open-circuit characteristics the recommendations for a choice additional air gap value in a magnetic circuit of the machine at its design are given. In family of open-circuit characteristics there is a point of intersection of all characteristics. If the point corresponding to a nominal operating mode of the machine is below a point of intersection of characteristics, it is necessary to choose the greatest value of an additional air gap as in this case the main part of the main magnetic flux will be created by permanent magnets. If the point of the nominal mode is above a point of intersection of characteristics, it is necessary to choose the minimum value of an additional air gap should be chosen minimum as in this case the main part of the main magnetic flux will be created by excitation winding. The on-load characteristic of the offered machine has good overloading ability. It is shown that in this design of the generator the superconducting excitation winding has to be used as the regulator of output voltage. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vovasov V. E., Betanov V. V., Gerko S. A. Calibration technique of navigation glonass receiver using combinations of dual-frequency pseudorange measurements. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 137-144. The aim of the work is to determine the settings of hardware delays in navigation receivers and satellite GLONASS transmitters in order to compensate ionospheric errors. The technique of the receiver calibration in this work is a method that does not use additional equipment to determine the settings of hardware delay algorithmic methods, taking into account the precise knowledge of navigation receiver position. The calibration allows one to retrieve values which are the difference of frequency-timing amendments not taken into account in the ephemerids. The assumption of the linear nature of hardware delay signals depending on the frequency allows one to determine the difference between the values observed delays in the L1 and L2 bands at zero, as well as announce changes lag of one type, in the ranges of L1 and L2, respectively. It is clear that these values are inseparable with the physical care of the timeline of the receiver and so will not have any impact on the assessment of the coordinates in the navigation solution. The proposed method of calibration was applied to double frequency navigation receiver Javad TR-GNSS G3T. The study has shown the technique is sensitive to the accuracy of the navigation receiver. Using the same unbiased weighted difference allows one to apply the navigation algorithm for obtaining unbiased estimates of coordinates GLONASS receiver. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goriachev O. V., Frolov A. A., Ovchinnikov A. V. Nonlinear mathematical model of percussive type piezoelectric motor with piezoelectric ring cell. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 129-136. The subject of this research is creation of an algorithm for piezoelectric ring cell coefficients calculation, piezoelectric motor static and dynamic characteristics study, setup of technique for piezoelectric percussive type motor with piezoelectric ring cell model coefficients. In the course of mathematical model setting up, we used decomposition principle, and split the model into three subsystems: - piezoelectric element, - spring pusher, - rotor. The updated algorithm for piezoelectric ring cell model coefficients calculation, based the dependences stated in reference [1] allowed to simplify design and analysis of piezoelectric motor characteristics. The paper presents the annular piezoelectric cell resonant frequency tuning technique. We plotted Bode diagram to specify resonant frequency of the annular piezoelectric cell, which allowed us to determine piezoelectric resonator resonance frequency. To create piezoelectric motor model we took into account the effect of the pushers represented by plate springs and described by compressed spring model. The model of the pusher also accounts for plate spring stiffness factor proportional increase. It allows ignoring trifling alterations of pusher to rotor slope angle. Comparative analysis of obtained characteristics and rated values lead to a conclusion on adequacy of obtained mathematical model. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mirzoyan A. S., Malyshev O. V., Khmarov I. М., Kanivets V. Y. Recognition of aircrafts by optical system in real time. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 145-156. Application field of the results of this research relates to the solution of the problem of aircraft recognition by optical systems to provide: - control of the air space by international missions at «hot spots»; - documentation of situations in the sky by military correspondents and witnesses, equipped with video techniques; - documentation of situations in the sky in border districts; - control of the air space by defense systems (also without using of radio channels) etc. The aim of the work consists in determination of aircraft type by recognition system through its 2D image on photo-integrated matrix of visible, ultraviolet or infrared range in real time. The proposed system of algorithms differs from its earlier developed counterparts mainly by recognition provision (with probability greater than 0.9) of 8 up to 12 types of military aircraft through their 2D dynamic optical images received by standard optical-electronic equipment and computing facilities. Operating principle of the recognition system bases on the following principle. It singularizes an aircraft against the background of firmament with subsequent formation of its outer contour. Then the system compares this received real contour of aircraft image with reference contours of aircraft digital models from a given class stored in long-term memory. Reference contours herewith should be obtained at all possible aspect angles of digital models. Among all reference contours, the system must sel ect the one with minimum deviation fr om the real contour according to given matching metric. The basic means for time acceleration of aircraft recognition consist of algorithms with preprocessing and proper organization of long-term memory. Application of the introduced algorithm of real and reference images matching by Nikodims metric makes it possible to implement recognition of aircraft type in real time. Working test of recognition system prototype hardware implementation on physical aircraft models and videotapes of real aircraft flights has shown high probability of correct recognition (0,92-0.98) with minimum time delays (40-280 ms). In addition we have a possibility to solve the problem of correct recognition with probability 0,92-0.98 in practical formulation for 8-12 aircraft types using the following standard hardware capabilities:
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Sidyakin S. V., Egorov A. I., Malin I. K. Recognition of moving human figures on video sequences using disk thickness maps. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 157-166. At present, the problem of object detection and recognition on video has many existed approaches to its solution. Methods herewith implementing object attributes description combined with machine learning algorithms gained maximum popularity. Any one of object characteristics, such as shape, color, or texture, can play the role of an object attribute. Some attributes describe local characteristics while other can characterize an object globally. Depending on attributes in use, one can decide whether such detector suits to solve the accompanying problem of object tracking. Moreover, in the case of a human figure — its posture analysis. One of the existing and potentially useful global object descriptors is rectangle cover, which was earlier used in [1] to solve the problem of automatic classification of moving humans. Rectangle cover represents the aggregate of all maximum empty rectangles, inscribed entirely into 2D figure. These rectangles were calculated by morphological opening operation. Correspondingly, to determine all maximum rectangles of fixed size, one should calculate an opening operation of the entire figure for each size of this kind. The entire process was extremely time consuming. Therefore, this approach appeared to be non-applicable for a large number of objects in picture. It worked very slowly even with three objects. The other problem lies in the fact that with application of a rectangle, we lose rotation invariance. The abovementioned problems defined the goal of the research: modification of method [1] in order to increase the speed and overall quality of the human figures detector. The algorithm for solving this problem consists of the following. Video contains moving objects and some of them are humans. During the first stage, we separate silhouettes of all moving objects based on background model building using mixture of Gaussians. This method provides a high density of pixels within the sel ected moving regions, as well as allows us to separate the shadows from the objects. During the second stage, we use continuous morphological models (skeletons) [2]. It allows to build morphological thickness maps (covers) (Fig.) of the objects effectively not for rectangular but for disk structuring element [3]. The advantage of using disk is its invariance to translation and rotation. This is a key step in the proposed algorithm. Disk thickness map is stable descriptor, contrary to skeleton, shown in [3]. Based on the thickness map object feature vector is generated. It is a set of disks, and five normalized parameters characterize each disk: radius, center coordinates, area, a number of unique pixels that were not overlapped by other disks. Further, classification stage begins. We need to determine whether the presenting silhouette, described by feature vector, is human or not. To do it we use algorithm containing extremely randomized trees. Every available disk is recognized within every tree. Each disk relates to a certain class by a majority of votes. Then votes fr om all disks are collected to make the final decision whether this silhouette belongs to a human being or not. Qualitative evaluations obtained allow to draw a conclusion that the proposed method successfully solves the problem of moving human silhouettes recognition. Application of disk thickness map leads to increase of quantity of correctly classified human silhouettes and reduces the number of false detections due to invariant properties of the disk thickness map. The proposed approach is superior in terms of performance to previously known method based on rectangular covers (12 objects are process at 10 frames Human disk thickness maps examples per second versus 3 objects at 5 frames per second). One can use this approach for video surveillance systems, installed in small placements with small human flow. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zherikhina L. N., Karuzskii A. L., Perestoronin A. V., Tskhovrebov A. M., Yarman T. . «Teleportation» of a magnetic disturbance in the superconducting slot line. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 167-177. The principal points considered in the article are focused around various aspects examining cause and effect restrictions of relativistic and quantum-mechanical origin on the transmission speed and the treatment of discrete information. In the introduction different approaches to Einstein-Podolsky-Rosen paradox and its actual generalization like effects, described by Bells inequalities, and also certain aspects of the problem history are demonstrated. Main content is devoted to features of a signal propagation in the closed slot microwave transmission line, metallic components of which are in the superconducting state. In case of coapplication of the classical model of the field screening in a superconductor and magnetic flux quantization in a closed superconducting circuit certain ascendant imperfection of the «usual» fluxon theory, connected with some contradictions, is demonstrated. Correlation of quantum fluctuations and propagation feature of pulsed magnetic disturbances in a closed extended superconducting circuit are analyzed in the context of Einstein-Podolsky-Rosen paradox. From presented evaluations it follows that the process of signal reception at the end of the superconducting slotted line with conservation of quantum coherence is possible under corresponding selection of detector parameters, such as SQUID. On the whole the performed consideration shows us that the macroscopic quantum phenomena constitutes not less abundant list of effects, than traditionally reviewed schemes of EPR paradox realizations, based on microsystems in the form of photon pairs, which are born in the entangled states. In the conclusive part the possible schemes of an experimental study of postfactum influence effects are considered, when the effects of influence on interference in a single macroquantum system from classical positions may be interpreted as the posteriori sequence of consequence-cause. «The post factum action» is realized as an impulse disturbance of the optical path length, introduced into one of shoulders of Mach — Zander interferometer. For «experimental facilitation» of the task in both shoulders of set-up optic delay on the basis of photon crystals, which is providing time lag, corresponding to the light propagation per cents of kilometers, are introduced. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zueva T. I., Khmelevoi V. V., Dzardanova S. V. Definition of the helicopter integral market competitiveness in the group of helicopters of a certain class. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 178-189. The problem of the competitiveness evaluation of aviation technology at the stage of making decision about buying and formation of the Park is relevant in connection with active development of transport system in russian regions and cities. Methods of the estimation of competitiveness that currently proposed in the literature and other information sources are not designed to cater for the increasing needs of customers, the number of private consumers aircraft increases. In the presented paper we describe the developed method in determination of the integral competitiveness of the helicopter in helicopter group of a particular class. The approbation of this method on the example of civil helicopters is given as well. The integral market competitiveness of the helicopter is encouraged to understand as the result of the comparison of each model helicopter candidate for purchase with the sum of analog — helicopters of different manufacturers, are on the feasibility and consumer characteristics, taking into account the blur variations in consumer preferences. It is proposed to use the method based on the theory of fuzzy sets, prioritizing in the assessment scales analyzed analogues helicopters for making decisions regarding the level of overall market competitiveness. The result of the competitiveness evaluation in the article is invited to consider obtaining a competitive range of helicopter models, prioritized on integrated index of market competitiveness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komarova A. M. Investigation of possibility of creating the mechanism of repair manufacture for the aviation components. Aerospace MAI Journal, 2014, vol. 21, no 5, pp. 190-195. Purposes
Design/methodology/ approach Using the methods of competitive analysis and segmentation of market to determine the perspectives of development of each engine modification that is produced and repaired at the enterprise. Conducting the research of process in organization of repair manufacture on example of «Chernyshev MME, JSC». Investigation is made by decomposing the object using the system approach and SADT-modelling. Using the method of process routing to determine the sequence of process operations and production equipment used. Using the methods of making the management decisions to determine the optimum load of equipment and route of transferring the product fr om one lim it to another. Originality/value The following statements and results presented in this work are new:
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Chotchaeva S. K., Shevtsov S. N., Flek M. B. Optimization of aircraft units mounting by using a database of their virtual computer models. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 25-38. The paper proposes a method for ensuring the required accuracy during the aircraft units mounting. The method was developed for the cases when the dimensional coupling structure of the assembly is represented by multi-link coupled three-dimensional chains. In such cases the assembly accuracy is attained via the adjustment method. Any change of one of the varied dimensions (of the so-called «variable compensators») during the attainment of the accuracy of assembly of such systems leads to the changes of all resulting parameters of the assembly precision. This is due to the fact that such dimensional chains are coupled. The output dimensional parameters are usually measured indirectly due to the difficulties of direct measurement of the relative spatial positions of the large-sized and heavy units. The adjustment process for such systems is implemented according to the trial-and-error method. The sizes of each variable compensator are consecutively changed and all output accuracy parameters are measured at each step of this process. The spatial positions of the adjusted points and output dimensions control points are separated by a relatively long distance. Therefore the adjustment requires the joint work of the assembly crew. This in turn leads to a considerable increase of the manufacturing cost and duration of the mounting and assembly. The presented method implies the development of mathematical (numerical-analytical vectorized) model of the mounted units. This model describes the whole geometrical structure and all dimensions of the assembly. The numerically stable algorithms, which allow the operator to solve both direct and inverse problems, are constructed for this model. The database with the virtual assemblies is created by using these algorithms. Random values are assigned to all internal dimensions of each assembly in the database. These values are distributed according to a certain law within the given tolerance ranges. Each record of this database contains information about the changes in the variable compensators, which are required to attain the required output dimensional precision of the assembly. During an actual assembly this information is taken from a similar virtual assembly and used to tune the output assembly precision. The proposed method is illustrated on the example of engine mounting technology for a single-rotor helicopter with two engines. The paper concludes with a discussion of the advantages and problems of implementation of the technology, which is based on the offered approach, in small- and medium-scale production of aircraft and rotorcraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grumondz V. T., Polishcuk M. A. The problem of guidance of a gliding unmanned aerial vehicle onto a moving target. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 7-12. A gliding unmanned aerial vehicle (GUAV) is considered. This vehicle is equipped with a high-aspect ratio wing and pneumatic control actuators. These elements make the long-range gliding flight of the UAV possible. The GUAV is the newest type of aircraft with improved performance. The problem of guidance onto moving targets is very topical. The paper considers the problem of guidance onto moving targets under the conditions of flying along the designated route. The route is defined by navigational guidepoints. The number of these points may vary. The paper suggests an algorithm for generation of the initial states sets for the GUAV with the purpose of fulfilling the given mission. This paper is the development of papers [4-7]. In contrast to [7] this paper suggests a modernized and improved algorithm for the generation of the initial states sets for the GUAV. This algorithm consists of several stages: the stage of determination of the possible states set for the target (the point where the target is situated); the stage of determination of the critical points within the previously defined target states set (the critical points are the points, which are hardest to attain for the GUAV under the given initial conditions); the stage of generation of the initial states set for the GUAV. In this case the generated initial states set would be created as the intersection of GUAV initial states sets for all of the chosen critical points. The target states set can be geometrically represented as a circle for the case of constant target speed. This paper illustrates some special cases, for example, when the target speed is low. In this case the target states set would transform into a circle with small radius, which can be geometrically represented as a point. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Egorchev M. V., Kozlov D. S., Tiumentsev Y. V. Aircraft aerodynamic model identification: a semi-empirical neural network based approach. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 13-24. The paper considers the problem of simulation and identification of the nonlinear controlled dynamical system on the example of angular motion of a highly agile airplane. The proposed semi-empirical dynamical neural network-based model combines theoretical knowledge about the simulated objects with the tools of model improvement, which perform training of artificial neural networks. The theoretical knowledge is initially presented in the form of differential equations, which describe aircraft angular motion. Afterwards this knowledge is transformed into modular dynamic neural network representation. Insufficient accuracy of the theoretical model is improved via identification of the (nonlinear) aerodynamic force and moment coefficients. These coefficients are represented by the MLP (multilayer perceptron) modules, which are embedded into the complete model. A representative training set is generated to achieve the acceptable generalization capability and reduce the time, which is required to collect the data. This set is generated via special procedures of control input signal optimization. Training of dynamical neural networks on long data sequences has proven to be very difficult. There are several reasons for these difficulties, which include the effects of vanishing and exploding gradients as well as presence of spurious the training of the dynamical neural network model is performed in incremental fashion as follows. In order for the gradient learning method to attain the deep enough minimum of the error surface the training must start with the parameter values, which are close to that minimum. The problem of obtaining such parameter values may be treated as a problem of searching for minimum of a similar error surface. Thus a sequence of error surfaces with the following properties is constructed: a) the first error surface is simple enough to search for minimum with any initial parameter values; b) each next error surface is similar to the previous one; c) the sequence converges to the original error surface. Thus the original training problem is decomposed into a sequence of more simple sub-problems. Computational experiments confirm the efficiency of the proposed approach: the modeling errors for the test set are where , are the angles of attack and sideslip; p, q r are the angular velocities about X, Y, Z axes.
Aerodynamic coefficient estimation errors for the test set are
where are the coefficients of body-axis components of the aerodynamic forces and moments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitchenko Y. A. The moment model for large mach number flows. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 39-48. The paper studies the physico-mathematical models of the flows, which are based on a system of moment equations. The main shortcoming of the moment equations systems is their short-wave instability. This flaw limits the use of the models in hypersonic regions of the flow. In [1] the system of Grads moment equations is extended to polyatomic gases. The publication offers a method of constructing such system with a smaller number of additional assumptions. The obtained 24- moment system has the short-wave instability properties, which are similar to those of Grads 20-moment system. Publication [2] showed that the main cause of the short-wave instability consists in the fact that the expressions for closure moments (4-th order moments), which were obtained by using the approximating distribution functions, do not satisfy the closure moments equations. This means that there is a discrepancy between the local and balance expressions for the closure moments. Thus the publication proposed the methods of the short-wave instability reduction. One of the methods was connected with the expansion of the moment equations system. Additional members (matching additives) were introduced into the local expressions for closure moments. The resulting expressions were ins erted in to the closure moments equation. The differential equations of matching additives were obtained as a result. The original 24-moment system together with the matching additive equations created a 45-moment system of equations. This system allowed the research team to expand the region of solutions that are free from short-wave instability. This work considers the method of [2], which is connected with the selection of the members with the highest order of magnitude from the matching additive equations. The paper considers two techniques of selecting the members with the highest order of magnitude. The first method consists in excluding the non- equilibrium stresses even from the members with the highest order of magnitude. The moments of the 3rd order, which are included into the members with the highest order of magnitude, are left unaltered. The second method implies excluding the deviatoric part from the moments of the 3rd order in addition to the above-mentioned alterations. The algebraic expressions for matching additives are obtained as a result of this exclusion. The obtained algebraic expressions are included into the differential equations of the 3rd-order moments. The usage of the proposed methods is illustrated on the example of the solution of the problem of the shock wave profile determination. This example shows that the obtained flow model allows the researcher to expand the region of solutions, which are free from the short-wave instability, close to the hypersonic Mach numbers ( M≈ 5 ). The second method of selection of members with the highest order of magnitude has significant advantages. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balyk V. M., Vedenkov K. V., Kulakova R. D. Methods of structural and parametric synthesis of multipurpose aircraft systems with multidimensional external heterogeneous target set. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 49-59. In this paper the method for structural-parametric system construction of optimal facial features flying objects is considered. For the case of a homogeneous target set the structural parametric synthesis is based on a statistical approach. For the case of multi-dimensional, heterogeneous set of targets the structural parametric synthesis is organized in the form of global search of the objective function. Multipurpose feature of flying objects is determined by the variety of tasks performed by the system, the conditions of its operation and by set of system elements. It causes a number of problems which are far from being resolved now. The main problem is related to the assessment of the aircraft effectiveness, when it is difficult to decide what rules should get an overall effectiveness assessment of the aircraft system performing predetermined range of tasks. Volume of processed information in the system is much more than information capabilities of its individual components and thus the system should use a set of elements. Construction of multi-purpose system is rational distribution of a given set of targets between the centers of X strategy for flying objects building system. It is shown than external replacement of X by some «calculated response» is unacceptable, since «design characteristics» often lead to a significant systematic error, and in some cases they may not contain. In this paper we present a solution to the model problem in which it is necessary to optimally distribute the targets between cruise missiles group. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhigastova O. K., Pokuchaev V. N. Software complex of automatic spacecraft flight planning. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 60-70. Purpose This article discusses software complex of flight planning of unmanned automatic spacecrafts. Complex was developed based on methodology of automatic flight planning [1] describing the procedure of automatic variant of flight plan making and its verification using simulation model of Onboard Control Complex (OCC) [5]. Design/methodology/approach Discussing way of software complex design includes formulation of complex creation problem, development of requirements and formulation of solving problems, structure definition and procedure of structure elements interaction. The main tasks solving by software complex are:
In accordance with the problems being solved the software complex has been divided into four parts. The first part of complex solves problems of general and daily flight plans. They contain data on the spatiotemporal spacecraft state, on executing control operations, spacecraft hardware modes and facilities of GACC, and other information related to the management of spacecraft. In the second part of the complex the checking for the presence of a flight plan errors and the possibility of implementing systems and devices spacecraft is performed. To do this, the complex includes a simulation model of OOC, which helps in modeling work of OOC of spacecraft when the flight plan is executing. In the third part of the complex it is prepared the plans for private systems and devices of spacecraft and GACC facilities ensuring the implementation of the flight plan. The fourth part of the planning complex ensures the organization and management of data generated as a result of the first three parts. To do this database and developed database administration software is used. The proposed structure of the software system proved its functionality and allowed to take into account all the features of the phase of drawing up a flight plan implemented over an extended period of time. Findings The task of creating software complex automated flight planning of unmanned spacecraft allowed to formulate requirements and complex tasks, build a structure that meets the characteristics of procedures for the creation of the flight plan. In the result of this work a software complex that allows to solve the problem of the automated task of plan creation and its automated verification has been developed. Due to created complex it is possible to simplify the procedure for flight planning, reduce the number of mistakes made by the specialist in the preparation of the plan, to make it more visible and comprehensible. Created software complex was introduced into practice management and used in the Mission Control Center (MCC) to manage automatic spacecraft of scientific and socio-economic purpose. Research limitations/implications Proposed automated flight planning software complex can be applied in the management of automatic spacecraft of scientific and socio-economic purpose flights. Originality/value
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Elkin K. S., Kushchev V. N., Manko A. S., Mikhailov V. M. Mars entry calculation for descent module of ExoMars project. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 79-86. The joint project ExoMars (ESA, Roscosmos) consists of two missions in 2016 and 2018 with the descent modules (DM) weighing 600 and 2000 kg respectively. Calculations for Mars entry optimal parameters of flight path modules were performed. The optimal nominal input parameters were obtained as velocity 5.817 km/sec and the entry angle 11.79 degrees. Scheme with an aerodynamic braking deceleration portion and a portion of the parachute braking subsequent embarkation with the soft landing engines was chosen. Calculations showed that the aerodynamic deceleration provides a decreasing in velocity of descent module more than in eleven times. DM velocity reaches about 500 m/sec at 220 and 200 sec (for mass of landing modules 2000 and 600 kg respectively). In this case Mach number is equal to 2.1 and 1.9 (respectively), which allows to use a supersonic parachute. There will be applied parachute of 12 meters in diameter for deceleration of descent module weighing 600 kg. For braking descent module weight 2000 kg it is proposed a two-stage parachute system with diameters 15 and 35 meters of canopy. Calculations showed that the landing deceleration parachutes provide decreasing in modules velocity to subsonic speeds of 50-60 m/sec and then begins the final stage of braking by a soft landing engines. Calculations showed that in condition of super-and hypersonic speeds Reynolds number varies in the range of (1-1.6)?106. Entry trajectory of Mars descent module trajectory in «Mach-Reynolds» coordinates shows the range of modeling parameters, which have to be provided at the stage of descent module experimental testing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yanyshev D. S., Bykov L. V. Gas actuator dynamics model and its equivocations. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 87-92. Gas actuators play a great role in modern aircraft building. However, a lot of difficulties occur while designing actuators with short operating time. The lack of adequate mathematical models results in the higher costs of experimental researches needed to optimize design. A model of gas actuator dynamic, generated by considering gas mass and energy balance in actuator cavities is presented in the paper. The balance equations are derived by integrating general continuity and energy equations over the volumes of actuator cavities and by using Gauss divergence theorem. The main equivocations of the model, which occur in actuators with short operating time periods, are revealed. The methods for eliminating these equivocations are given. The modeling results obtained, using adjusted model, are stated. In this paper it is shown that in case of short operating time actuator a zero-dimensional model of a gas actuator yields to substantial errors. These errors could be corrected by 3D modeling and by using the experimental data. The non-uniform pressure field inside the actuator is the main factor that influences onto actuators dynamic. The second factor is the velocity profile. And the third important factor is a width of technological gaps in an actuator since these gaps define mass flow rate being exhausted from the actuator. Authors reveal that the first and the third factors are of utter importance, while the second one could be sometimes neglected at all. In this paper authors use two extra coefficients derived from the results of CFD-modeling and test data to adjust the mathematical model of the actuator. The model after modernisation could be used for design optimization of the actuator. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gobor I. N., Dipner A. A., Ozolin V. V. The total solar irradiance in space research problems. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 71-78. In this article it is shown that the accuracy of pyrheliometers installed in artificial Earth satellites and applied for measurement of solar constant or total solar irradiance (TSI) is insufficient for measurement of long- term variations of TSI at the level of 0, 1% per years. The calibration method of pyrheliometers by feeding on them monochromatic radiation of several lasers with stable energy characteristics and different wavelengths is considered. Three methods of accurate laser power measurement are debated: with the help of cryogenic vacuum radiometer, silicon planar photodiode with additional transparent electrode on illuminated area and method of laser PIN- photodiode comparison. The relative error of a measurement of laser power by the first method is 0,01 — 0,03%, and it is estimated by the computational way. If one applies silicon planar photodiodes, it strives growths of quantum efficiency up to 100% (on the statement of authors) by the feed of growing potential on the transparent electrode. Some independent researchers consider that the relative error of a measurement of a laser power by the given method could make up 0, 3%. The third method is based on the application of planar photodiodes with external or embedded temperature detector. If one feeds the calibrated electric power on such photoconvertor, then it is translated into heat flow copying as on coordinates as at whiles the heat flow induced by dissipation of radiation in photoconvertor due to a drift of charge carriers initiated by the radiation. Because of this the error of laser power measurement drops to 0, 001%. Two methods for control of residual connected with inequivalence of optical radiation and electric current conversion in heat flow are pointed out. First is based on the use of two operating modes of photodiode — short circuit and idle pitch, second is realized by the variation of thermal environment characteristics near illuminated surface of photodiode. То increase the right verification of TSI variations it is offered to create an imitator of TSI and to strive a suitable reproducibility of Earth measurements in conditions analogous to orbital ones. The principle possibility of application of TSI monitoring results for forecasting flares of solar activity is mentioned, which should increase the reliability of aerospace electronic systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chesnova V. A. The way to develop a promising technology for creating a design of the heat-stressed parts in the turbines of aircraft gas-turbine engines and gas-turbine plants. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 93-108. The object of research is high-stressed parts of high-temperature gas-turbine engines (GTE) and gas-turbine plants (GTP) with the complex of branched channels. The aim of the research is to develop a methodology for creating and designing of cooled structures in high-temperature gas turbines of GTE and GTP of 5-6th generations by using the experimental database to ensure the competitiveness of aircraft engines due to innovative technologies used for their creation. The complex program of thermal designing the heat- stressed parts of the gas-turbine engines and gas-turbine plants for increasing the reliability and lifetime of the engine is developed. The methodology of mining the heat-stressed parts on the stage of the design- technological adjustment of cooled parts is developed. New criteria relations dependence characterizing the thermal and hydraulic conditions of perspective systems of heat exchange intensification of the cooled gas-turbine blades are obtained. The data bank for channels with complex configuration of modern systems for intensifying heat exchange in the high-temperature gas turbines of gas-turbine engines and gas-turbine plants is compiled. Scientific novelty of the research as follows: the complex program for thermal designing and improving the structures of heat-stressed parts in GTE and GTP aiming to increase the reliability and service life of the engine by using the highly informative methods of research and by controlling of their functional parameters is developed. The developed bases of technology of working off of the constructions of heat-stressed parts on the stage of the design-technological operational development allow to reduce the complexity and expense for the creation of prototypes of the aircraft equipment. The received samples of the design elements of the aircraft equipment can be used in the development and creation of modern and perspective gas-turbine engines, and also in the process of building of heat-engineering devices. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolaenko V. S., Filippov G. S., Jashenko B. Y. The problem of reducing the thermal signature of an aircraft engine. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 109-114. For calculating the indicatrix of infrared radiation (IR) signature propulsion aircraft developed. A new technique based on the Monte Carlo method for calculating the signature of infrared radiation produced by an aircraft propulsion system is developed. This method is used for solving problems by simulating random variables. Calculations are performed by example of AL-31F engine. The turbulent gas flow inside the nozzle is simulated by solving Navier-Stokes equations. For calculating the heat transfer in the wall of the nozzle the grid and geometry of the nozzle are generated. The temperature distribution inside the aircraft engine result is obtained. During simulation the inner surface of the propulsion system is modeled cones, cylinders, hyperbole, turbine ring, the central body ellipsoid. Infrared radiation are varied in a wide range of angles. In order to reduce this level, we offered to implement a special screen, which is a cylindrical surface extending over the nozzle exit. The screen diameter is large than the diameter of the nozzle and can significantly reduce infrared radiation in the range of angles from 10 ° to 90 ° depending on its configuration. The results of calculations for the
screening element with a different radius r, the length h and the distance to the nozzle exit plane H is shown in figure. But the usage of such screens is difficult in existing aircrafts. Its overall efficiency is increased slightly with screen size increasing (since the length of 0.85 m). By using a special screen design there is a significant (98%) reduction of infrared radiation in the radial direction. But the level of radiation along the axis is increased. In this screen geometry (length and diameter) are important parameters. The choice of screen geometry defines by designers of airplanes. For the terrestrial infrared equipment matters most radiation in the radial direction and using of such device may be effective. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. Energy supply system of the spacecraft with long-term lifetime. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 115-122. Under a spacecraft (SC) with long-term lifetime we mean a vehicle with an active shelf operating time of about 10-15 years. SC should be considered as a unified energy system which consists of a number of interactive subsystems. The main part of the SC power system includes an energy unit (EU) which provides the energy for all power consumers. Only solar or nuclear energy can be considered as primary energy for the vehicles under examination. At the present time it is the basic primary energy source for the low-earth SC and for the Sun directed probes. The main way for developing of the space solar power usage is the direct photoelectric conversion of the solar radiation. The development of huge power energy production (more than megawatt) will require the application of the nuclear power sources. The main part of the SC EU is an energy accumulation system based usually on the storage battery (SB) that presents the major part of the entire EU mass and often determines the battery life. The lifetime of the modern SB depends on the operation conditions and it ranges from several hundreds of charge-discharge cycles (Ag-Zn) to dozens of thousands of cycles (Ni-Cd, Ni- H2). The required SB life time depends on the SC orbit and is achieved by the deducting the discharge level. The life cycle of modern capacity storages (supercapacitor) is greater by an order than it is for any other SB but their specific energy characteristics are much lower. Due to the increase of the suitable SB mass in case of the discharge level reduction and quite big amount of cycles the capacity storage characteristics will make them a promising energy storage system. At the present time the Li-ion SB is widely used in SC on-board power systems. The necessity to use Li- ion SB as a part of the SC is caused by the increasingly stringent requirements for the increase of the specific power loading and reliability of the on-board power source. At the present time the life time of the Li-ion accumulators is insufficient for the SC under examination (near 1-2 thousand of charge-discharge cycles). The possibilities of the life time increase by means of the discharge level reduction (by analogy with Ni-Cd SB) have been studied insufficiently. However the continuous improvement of these sources allows to hope that of the required life time characteristics in the future. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Veskov Е. V. Finding of fuel rests in system a tank-feedline of launch vehicle with the help of ANSYS CFX. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 123-131. The solution of the task of propellant unloading fr om the tanks of launch vehicles is extremely important to solve the problem of the minimal propellant residuals determining. This fuel residuals prevents of tank pessurization gas enters in the feed line of liquid-propellant rocket engine. The pressurization gas gets into the feed line from the fuel tank through the drain hole at the stage of complete emptying of tanks and the «broken» of the free surface of the fuel due to the formation of the funnel. The critical level of fuel preventing gas bursts out into the feed line is largely determined by the drain hole structure and the Froude number. The formation of a gas-liquid mixture is occurred due to the collision of the gas flow from the tank with the surface of the fuel in the feed line. The entrapment of the pressurization gas and its penetration into the fuel are results of this collision. The propellant residuals in the tank and the feed line are determined by numerical simulation of this collision. The numerical simulation of the liquid detanking process is done with the help of ANSYS CFX software package. To solve this task a combination of the method of calculating the current of continuous multiphase medium with free surfaces (Volume of Fluid) and the method of calculation of the current of multiphase polydisperse medium, wh ere a liquid phase is continuous and a gaseous one is represented by a set of bubbles of different sizes (Multiple Size Group model), is used. Until the moment of penetration of the gas jet from the tank at the free surface of the fuel in the feed line, the calculation is carried out by the method of VOF. The calculation of a gas-liquid mixture in the feed line is carried out by the MUSIG method. The results of the calculation are well correlated with the experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fokin D. B., Isyanov A. M. Optimal shape of power plant for perspective attack unmanned aerial vehicle. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 132-143. At present time the attack unmanned aerial vehicles (UAV) with large take-off weight is the most interest among the wide variety of UAV. These UAV can carry a certain amount of armament besides a reconnaissance equipment. In the USA the development of ship-based unmanned aircraft systems (X-47B, «Phantom Ray», «Sea Avenger» and «Sea Ghost») is leaded more actively in the UAV class. The European projects, such as «nEUROn» and «Taranis» and Chinese project («Lijian») are also known. The development of the UAV with attack opportunities in our country began at the end of 1990 years. The development of aircraft of such class engaged «MiG» corporation («SKAT»), the design engineering bureau named Yakovlev («PRORYV») and others, but presently none of them reached the fase of serial production. The requirements to the power plants of such aircrafts are formed on the basis its implementation and solwing tasks. This includs the regimes of takeoff and landing, acceleration, maneuvering in horizontal and vertical planes and other. The analysis of influence of design parameters of both the engine and aircraft, such as bypass ratio, takeoff thrust, the gas burner exit temperature, the overall pressure ratio and the wing area on the course of UAV performances is given in this work. The ultimate aim of mathematical modeling at the aircraft design and its power plant is the optimal values obtaining of its design parameters and optimal control schedules. The solution of multicriterion problem on the initial design stages is advisable to carry out in accordance with known Pareto principle. According to which the area within the limits of which cannot be increased any partial criterion without reducing other ones must be identified in the area of arguments. The range at different conditions, acceleration, normal load factor of steady turn and takeoff weight with normal refuelling are acted as criteria for UAV operation. The multicriterion multifactor optimization of the design parameters of the considered UAV is demonstrated the posibility of significant improvment the aircraft performance versus the preliminary version. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhodzishskii D. M. Intra-periodic fluctuations of dynamic tracking errors in digital pll with frequency-phase control. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 144-152. With third-order astatism a phase-locked-loop frequency control system can be described by the following equations
Here is the adjustment period; i are phase and frequency of NCO (Numeral Control Oscillator) after completing the i-th adjustment period;
is the number in the third integrator of the PLL loop filter equal (in a steady-state mode with no noise) to the derivative of the incoming signal frequency ; is the signal at the output of the PLL discriminator; are coefficients of the loop filter determining dynamic and noise properties of the system. These equations are still valid for the second order if . Incoming signal phase instability results in PLL tracking errors which we will name dynamic ones. Here is the phase of the incoming signal, is the NCO phase at any random time instant t.
The paper considers dynamic errors in a steady-state mode. Such mode occurs after transient processes completion when , where n is PLL astatism order, and m is the order of the polynomial describing . In steady-state mode the tracking error averaged over the adjustment period when and when . However, tracking error instantaneous magnitude can vary within the adjustment period, i.e., intra-periodic fluctuations occur. The paper presents analytical equations for such intra-periodic fluctuations. The results obtained can be implemented for PLL systems design to determine ultimate dynamic effects possible for such systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivlev A. N. Abstract Development prospects of electric power systems for aeronautic complexes. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 153-160. A problem of on-board equipment electric power supply always arises during prospective aeronautical complexes design. Judicious and justified selection of electric power system contributes to substantial time saving during design and realization of new airship. Validation of electric power system type selection for aeronautical complexes, based on automated aerostats or unmanned airships, is generally carried out by expert analysis main mass-energy characteristics of power sources. Basis of such comparison and selection of optimal electric power system is relied on the condition of maximum values of energy performances with minimum weight and costs. Prospective aeronautical complex assigned missionsuccess requires high altitude and flight duration, as well as heavy payload weight. Prolonged flight duration requires protracted operating time of on-board equipment and purpose-oriented payload. The necessity of new types of electric power systems application onboard prospective aeronautical complexes stems from the fact that these complexes will include aerostatic aircrafts utilizing carrying gas heating. This heating is performed by thermodynamic processes in enclosed gas volume using a heat source, heated by chemical-electric method.Due to poser sources, small storage capacity present-day electric power systems cannot provide required flight duration and power loading of an aerostatic aircraft. Moreover, increasing the number of power sources certainly leads to addition to flight weight and correspondingly to payload weight reduction. Prevailing conflict resolution is provided with prospective electric on-board power systems application, and in particular such systems that can maintain on-board equipment operation of an aerostatic aircraft, as well as operation of purpose-oriented payload. These systems should have, herewith, improved energy characteristics and light load. Prospective aeronautical complex assigned missionWe carried out analysis of main mass-energy criterions of power sources for aeronautical complexes electric power systems in comparison with home-produced chemical current sources, as well as prospective electrochemical generators and photovoltaic power systems. The results of the analysis show: 1. Chemical current sources, namely batteries, do not meet the requirements imposed by prospective aeronautical complexes power systems, due to low energy characteristics and heavy load. In addition, for extended operation at altitudes higher than 16 kilometers chemical current sources need heat insulation by way of water heat storages. Implementation of heat insulation leads to 30% increase in electric power system weight, which is limited by payload weight and mass balance of an airship. 2. Electrochemical generators to a certain extent meet the requirements to aeronautical complexes energy characteristics and operational capacity. However, we need to allocate a stock of fuel cells (reagents) that also results in unacceptable increase in weight of electric power system. Thus, it imposes the same limitations as chemical current sources. 3. Photovoltaic system is best suited as a basis for prospective aeronautical complexes electric power system. Photovoltaic systems, namely solar batteries, enable electric power generation directly from Solar light energy. It compares favorably with energy characteristics, high-altitude flight capability and relatively low weight. To provide on-board equipment operation in the nighttime the photovoltaic system includes battery charge-discharge controller, as well as batteries themselves. It, somehow, burdens the whole system. However, due to implementation of thin-film solar batteries the total weight of the system is not very high. Thus, the possibility to generate electric power almost in every point of the Globe, stability of performances, high reliability, and long service life without maintenance in all climatic zones combined with absence of give-away factors include photovoltaic power system among prospective electric power sources. Photovoltaic power system combined with batteries offers necessary and sufficient electric power system for prospective aeronautical complex. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Roshchin A. S., Ananyev A. V., Borisov D. M. Real gas thermodynamics influence on solving Riemann problem under high temperatures. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 161-167. Consideration of temperature dependence of gas thermodynamic properties is necessary to solve the gas dynamics equations at high temperatures. The effect of the variability air thermodynamic properties such as the heat capacity and the adiabatic coefficient on the Riemann problems solution was studied. The Riemann problem was solved in prediction of constant gas heat capacity in all volume, in prediction of different heat capacity from left and right of the contact discontinuity, and finally considering the real gas thermodynamics. These approaches were compared on the groundwork of three test problems with the solutions containing two shock waves, one shock wave and one depression wave, and two depression waves correspondingly. It was shown that for the Riemann problem with high temperature difference the second approach gives better results as compared with the first one, but sometimes it results some unphysical simple discontinuities appearing at points of contact discontinuities. The effect of used numerical schemes to the solution of the Riemann problem was also examined. The Euler equation for the supersonic flow around wedge and berm was solved by Godunov scheme and its TVD modification using exact Riemann solvers for gas with constant or variable heat capacity. For all mentioned problems the computed air stagnation temperatures behind shock wave were compared. For the supersonic flow (M=10) around the berm modeled by the 1st order Godunov scheme the stagnation temperature error was less than 0.5%, and the 2nd order TVD-modification scheme resulted the 0.8% and 2% relative errors for supersonic flows with M=6 and M=10 correspondingly. It was also shown that for weak waves the flow patterns altered insignificantly. Finally, it can be noted that the use of Riemann problems exact solution combined with high order Godunov-type solvers can be efficient for solution of gas dynamics equations for real gases with variable heat capacities. This approach for flows with strong shock waves allows one to obtain accurately flow patterns, shock wave positions, and gas parameters behind wavefronts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Garibyan B. A., Spirin G. G. Computation of effective thermal conductivities of aircraft materials using the action variable. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 168-180. A variety of inhomogeneous materials currently can be estimated in millions and annually increases. All kinds of composites, compounds, alloys, fibrous, porous and granular materials, and bounded media are now widely used in aerospace engineering. The studying of thermophysical properties of aircraft materials, including thermal conductivity coefficient, is a very topical problem due to the application for new coatings of structural elements, thermal insulators, plastics, material compounds, rubbers etc. Here the definition of effective thermal conductivity of binary matrix type inhomogeneous materials is proposed. We use the theory of generalized conductivity [1], and the environment structure modeling is based on the unit cell method. Using the ergodic hypothesis [1, 2], the volume averaging is through the «action» functional [3] defined for steady temperature fields (1) This functional defines an integral characteristic of the field [3, 4]. The linearization of temperature field within the unit cell is carried out by Rayleigh-sections method [2]. The «blurring» of the material properties is by the equality , introduced; here is the effective «action» (1) with the thermal conductivity factor . Depending on the sequence of sections and the geometry of formed areas, i. e. sections schemes, we obtain different expressions for the effective thermal conductivity of cell.
The proposed method allows one to confirm the well-known formulae and get new ones for the relative effective thermal conductivity coefficient inhomogeneous materials (having isolated inclusions, interpenetrating components, and flat-fibrous). Also we have to establish the relationships between them, to estimate the discrepancies of values, including the most unfavorable case of very inhomogeneous environment: .
To compute numerically the effective thermal conductivity value within unit cell we formulate transient initial boundary value problem of heat transfer having no artificial restrictions adopted in approximate analytic approach.
This problem was solved for all types of unit cells of considered inhomogeneous materials on the basis of the rectangular regular grid by fractional steps method [5]. We use here an implicit difference scheme obtained by the control volumes method [6]. Due to the transient statement of the problem the pseudoviscosity method [5] was used; for the quasi-steady thermal regime onset in the unit cell we take the time at which the equality of heat flows at the end faces is true with the given confidence level p. The distribution of the temperature field in the cell corresponding to the time being a grid function is considered as approximate numerical solution of the steady problem. Applying the general «action» procedure by equating we can compute the effective thermal conductivity coefficient as follows:
(2)
Here is the base value (1), are the mean temperatures on the cell end faces that are numerically computed on the known grid , and L is a cubic cells edge length.
The effective thermal conductivity for various unit cells of inhomogeneous materials mentioned above that were computed on the groundwork of the formula (2) agree with the existing as well as new combined approximate analytic formulae.
A practical implementation was shown by computing the effective thermal conductivity of various inhomogeneous materials for aircrafts, such as the CFRP. The technique of restoring of effective thermal conductivities was developed for binary metal alloys with limited solubility of components. The efficiency of the proposed approach was shown for the binary system Al- Mg at the temperatures between 20...100...200(С. Also the effective thermal conductivities of triple-component alloy AMg5P (1557) were obtained using some different methods. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilin A. N., Kuznetsova E. L., Kurdumov N. N., Shalashilin A. D. A kinematic hysteresis model for an overhead transmission lines anti-galloping damper. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 181-188. Torsional Damper and Detuner (TDD) is a mechanism for detuning and attenuation of low- frequency oscillations of OHL conductors galloping. The oscillation energy is dissipated in the damping unit (DU), which represents a structure of two disks interconnected by the joint revolution axis and an ensemble of viscous-elastic elements, which react in relative rotation of disks. One of disks is a leader and is connected to the phase conductors via a rigid frame. Another disk is a follower and is connected to the balancing lever of pendulum type. A mathematic model of TDD functionality is developed for selection of geometric, mass and viscous- elastic parameters enabling the effective operation of the device in the frequency range 0.1-0.4 Hz. This model takes into account the hysteretic type of power dissipation appropriate to the type of DU under consideration. The process of hysteretic deformation of viscous-elastic elements due to their displacement inside DU is of extreme complexity and cannot be subject to a rigorous mathematic description. That is why the approximate methods are traditionally employed making use of experimental data. One of approaches consists in substitution of hysteresis by viscous-elastic deformation using the tension-compression diagrams of the elastoplastic samples and a logarithmic decrement of vibrations. Another possible approach consists in assignment a-priori of a diagram of deformation after a model of Drucker-Prager. According to this model, the hysteresis diagram is represented by a parallelogram inclined by a certain angle around its center. However, the use of such models may cause serious errors in selection of TDD structural parameters, since they do not take into account the shape and «size» of path along the deformation diagram which defines the stiffness of a damping unit and its transfer function. In this work a cinematic model of hysteresis is suggested which relates upon the hysteresis diagram. According to it, the torque and relative angle of torsion are related one to another via a special differential equation of the first order, its coefficients being defined after experimental values for the limit hysteretic cycle. In this case one succeeds to describe, in a single equation, an infinite set of similar cycles; each of them is uniquely defined by a position of a starting point on a deformation diagram inside a limit cycle. Similarity of these curves is defined by their asymptotic approximation to the limit cycle curve. Such a model results in a natural definition of hysteretic cycle «orbital» under external harmonic action on DU. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mezina N. A. Place and role of national research university in the formation, development and maintenance of human capital of knowledge-intensive and high-tech industries. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 189-195. Purposes
Methodology of work/results Used the methodology of constructing educational systems for various categories of students in the context of different age groups and skill levels of employers at enterprises of aviation industry. Considered possibility of a national research university in the formation of human capital of the aviation industry. Defined the levels of final learning outcomes and their contents. Show the ways of improving university management system, implementing an integrated system of education. Conclusion The article shows the need to establish an integrated system of training of human resources in aviation industry, which includes all the blocks of the educational process. Justified expediency of ideological concentration throughout the system on a national research university, which is able to bring together, for the benefit of industry, educational institutions of various levels and education structures of industry enterprises. Formed proposals for reorientation of university management to centers on the creation of value whic hare the department (cathedrals) that directly implement the target function in university. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozelkov O. A. Stochastic model of optimization of production large-nomenclature plan. Aerospace MAI Journal, 2014, vol. 21, no 4, pp. 196-202. Subject of study in the article are models and methods of personnel reserve formation of enterprise modernization projects. The aim is to develop methods of competency provision evaluation of the staff in order to improve the efficiency of personnel maintenance of the project. Tasks are: planning and estimation of goods production volumes taking into account the presence of raw materials, power, ware-house and other resources, the imaginary from products realization profit and production inputs; evaluation of the required composition of enterprise equipment and the perspective plan of production, composition and technical descriptions of equipment. Methods are: mathematical models of production plans optimization with stochastic presentation of parameters; method of indefinite multipliers of Lagrange. The following results were obtained. It is shown that problem of production planning is in unstable terms, in particular: level of material well-being by resources, occured from realization of products, expenses on storage of unsold parts, losses from a deficit taken to the task of the mathematical programming. The exact and close algorithms are offered for the decision-making in this task. Parametrization of task, providing possibility of construction of calculable procedure decision, adaptive to changing descriptions of production and products realization, is conducted. Intercommunication between the index of products issue planning realizability and probabilistic character of production parameters is investigated. Conclusion. In the result the model of planning of large-nomenclature production is improved in the conditions of vagueness. It can be used for solving the production planning problem for maximal realizability in the set term taking into account the estimation of the resource providing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leonov A. G. Outstanding scientist and designer of missiles and space-rocket technology. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 7-13. This article is devoted to the 100-year anniversary from the birthday of one of the most outstanding scientists and designers in the field of missile and rocket-and-space technology, Vladimir Nikolayevich Chelomey.
Examples are given for most important technical solutions such as unfolding of missile wing during the flight which has become worldwide common practice in cruise missiles creation. Operational advantages of such solution are obvious.
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Dovgodush S. I., Pavlov V. P. Retrospective analysis of the first cruise missiles developed by v.n. chelomey. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 14-20. The conditions that necessitated the creation and development of Navy cruise missile with special warheads aimed for ground targets destroy are analyzed.
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Petrovskii V. S. Combination of lexicography and nonlinear programming methods for multiextreme solutions searching. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 21-28. One of progressive applied methods for solution to a problem of nonlinear programming in difficult technical system such as the aircraft is presented. Process of a system shape choice always takes place in conditions of incomplete information. It is caused by uncertainty both in real conditions application and prediction of preliminary technical solutions feasibility. The choice of the only optimum decision is conditional and therefore unacceptable. With respect to conditions the one decision can be difficult to realize and very expensive in comparison with other possible solutions, which earlier were seemed not optimum and therefore were not revealed by traditional methods.
The stated approach prepares a basis for repeated optimization.
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Palkin M. V. Questions of satellite formation flying design and control. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 29-35. This paper presents a review of the following issues for the satellite formation flying design and control problem: group configuration, reference orbit formation, intergroup subordination. Results are based on the mathematical simulation of formation flying on low earth orbits.
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Sereda V. A. Pneumatic drive of ground catapult with free piston. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 36-43. Purpose
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Biruykov V. I., Pronin O. Y. Mathematical modeling of acceleration dynamics of test object till 3-4 M number on installation «rocket rail track». Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 44-52. For achievement of hypersonic speed of pilotless flying machines it is necessary to find the solution of some technical problems connected with processes of an aerodynamic flow of flying machine surface, as well as heating and strength of its structure elements. It should be also performed the works on creation of the athodyd engine (Ramjet) with wide range regulated speed air stream. With respect of perspective multimode supersonic Ramjet working process investigation the ballistic problem of the flying machine with Ramjet (object of test) test on experimental installation «Rocket rail track» is considered. The installation represents monorail track specially designed with a small gradient angle in length of 3,5 km (nowadays the works on its lengthening up to 5 km are conducted) on which the rail carriage set powered by solid fuel rocket engines with the thrust 450 кН is placed. The increase of installation thrust-to-weight ratio level is possible by increasing of engines quantity.
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Guseynov A. B., Trusov V. N., Polunin S. P. Analysis of the problems of creating hypersonic aircraft. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 53-62. The article outlines the main trends of hypersonic technology development by example of carried out in the world researches. The analysis and synthesis of these problematic issues of hypersonic technology development in the field of high-speed aircraft (AC) shows:
In the world is given the highest priority to backlog development in scientific, technological, methodological aspects for hypersonic aircraft. In the next decade on this basis will be created high-speed devices for different applications. Among the leading foreign countries the most progress in the implementation have made of U.S. government programs Hyper-X, Hy Tech, X-51A, Hy Fly etc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shcheglov G. A., Lukovkin R. O. Dynamic analysis of the plastically deformable spacecraft lander leg. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 63-72. It is proposed to use crash-boxes instead of traditional honeycomb elements in the spacecraft landing shock-absorbing device. The developed design- parameter selection procedure provides a safe spacecraft landing process.
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Dzesov R. A., Zhukov V. N., Melnikov E. K., Pavlov V. P. Ballistic analysis of fast scheme for rendezvous between transport vehicles and the international space station. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 73-79. Ballistic analysis of the four-revolution scheme of the rendezvous between transport vehicles (TV) Progress and Soyuz and the International Space Station (ISS) was carried out.
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Nadiradze A. B., Smirnov V. A. The way to simulate meteoroids and orbital debris impact to spacecraft elements by means of monte-carlo method. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 80-91. This article discusses an algorithm of Monte Carlo impact ids and orbital debris on elements of spacecraft. A feature of this algorithm is the use of group method. In which all the particles are separated into a plurality of classes. Division into classes produced by the distribution function parameters (mass density, diameter, speed, direction of the velocity vector) and the angle of impact with the target. For each target for each class are calculated the parameters of interaction of particles with a target particle and the parameters for particle fluxes penetrating capable goal target. The result is a matrix of interaction parameters and matrix penetration («the transformation of the table»), which are then used in the integration. This allows several orders of magnitude increase computing speed and significantly increase the accuracy of calculations at a reasonable computation time. This allows several orders to reduce the amount of computation and significantly increase the accuracy of calculations at a reasonable computation time. Furthermore, the considered algorithm allows efficient parallelization, allowing further increase its performance. To illustrate the algorithm in the article shows the results of the impact meteor streams and technogenic particles on the spacecraft solar panels and fuel tank disposed within the housing spacecraft. Such calculations require high spatial resolution, which is to get with a small number of trajectories is not possible. However, the proposed algorithm can solve such problems at a reasonable computational time. It has been found that the presence of even small gaps (5-10 mm), there is a significant increase in the density of particles damaging flow inside the spacecraft casing. The reason for this is the increase in flow of damaging high-speed streams of small particles. The algorithm performance on modern PCs are estimated at 2 ? 104 vertices / h with a geometric model complexity 1-2 million triangles and the resolution of 105 rays/vertex. The proposed algorithm and its implementation can be used for design of spacecraft operating in Earth orbits. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveev Y. A. Optimization of the process of developing aircraft with two-level system management of project implementation. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 92-100. Statement of research problem
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Bykov L. V., Bogachev E. A., Elakov A. B., Beloglasov A. P. The usage of nonwoven carbon materials in high-temperature heat exchanges of C-SIC structure. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 110-117. The existing air heat exchangers made of aluminum or stainless steel, do not allow to implement highly available power of aircraft without losing mass perfection. Thats why the leading aircraft manufacturers conduct intensive researches aimed at creating high heat exchangers made of nonmetallic materials. Composite materials can be regarded as the most attractive for the manufacture of structural elements such heat exchangers. The replacement of metals by high temperature oxidation resistant and erosion resistant composite materials, which have significantly higher levels of specific strength (relation of strength to specific gravity ) at temperatures of 700-900oC and above, will dramatically improve the mass-energy characteristics and increase the competitiveness of the new generation of products. At the same time, composite materials with the reinforcing framework made of thin nonwoven carbon materials or of silicon carbide ones produced by using of a special hydrodynamic machining (Spunlace-method) are more promising than materials derived from the tissue.
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Gabrielyan D. A., Semenov V. V., Uteshev A. A. Magnetic systems of thermo magnetic energy devices. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 101-109. The purpose of this work is to analyze existing systems for thermo magnetic energy devices for wide spectrum of application and to describe the optimal magnetic system for thermomagnetic engines (TME).
Design/methodology/approach The revue about magnetic systems for thermomagnetic energy devices based on permanent magnets (magnetic cooling machine, magnetic thermal generators and thermomagnetic engine) was done. The publications for the last 5 years were considered. It was proposed to classify the magnetic systems used in thermomagnetic energy conversion technologies in three groups. Results For magneto caloric refrigerators and thermo magnetic engine its magnetic systems have a fundamental difference in the distribution of magnetic induction along the active working ferromagnetic body. For refrigerators magnetic systems requirements are:
Research limitations/implications This research provides development of non-traditional methods of mechanical or electrical energy production based on thermomagnetic effects. Originality/value There is a lack of magnetic system designing data for thermomagnetic energy devices described in literature and, on the contrary, there are a number of works in which presents an analysis of the existing systems for magnetic refrigeration. The magnetic refrigeration systems are introduced different criteria for evaluating the effectiveness and feasibility of the application of a system [15] and examines possible field configuration and geometry of magnetic systems [4, 510]. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Klykov A. V., Nguyen V. H., Tomilin M. M. Simulation model of electrostatic discharges impact on spacecraft on-board cable network. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 118-127. Purpose
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Tin P. . Automation of aircrafts operational distribution among landing approach traces at moscow terminal control area in sudden change of weather conditions. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 128-140. When an aircraft approaches Moscow terminal control area, an air traffic controller instructs the crew to push down and vector by beacons. Orienting by radio beacons and following air traffic controllers instructions the plain approaches a final approach track or a landing trace matching strip magnetic direction. Selection of the strip itself depends on a number of factors, such as saving and flight safety account under limited fuel reserve, and performed according to a special algorithm.
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Nerubailo B. V., Kargaev M. V. Differential equations for the physically orthotropic cylindrical shells under action of circle loads. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 141-150. The article is devoted to an actual problem from a field of strength of aviation and rocket-cosmic thin- walled constructions such as solution to boundary problems for a definition of their stress-deformed state on the basis of high defining differential equations in the partial derivatives. An object for investigations is the circle cylindrical shells made from material, which has different elastic properties in the three mutually perpendicular directions, i.e. the physically orthotropic cylindrical shells.
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Bobylov A. A., Belashova I. S., Kuzmin S. D. The contact problemof indentation of a functionally graded coating by a convex punch undera predefinedload. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 151-160. The nonlinear plane contact problem of indenting a hard punch in an elastic body with functionally graded coating is considered. The main vector and the main moment of the external forces applied to a hard punch are assumed set. Unilateral contact conditions are given on potential contact area on which the elastic body and the hard punch may come in contact. Thickness of the coating is commensurable with the sizes of the spot of contact. Such scheme is applied at research of discrete contact of rough bodies.
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Kozelkov O. A. Stimation of competent reserve at forming of the skilled providing of enterprise modernization plans. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 161-167. The subject of research in this work is models and methods of forming of skilled reserve of enterprise modernization projects. The aim of work is development of estimation methods of employees competent reserve for the increase of efficiency of the skilled providing of project.
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Ivanisov V. Y. New organizational-economic concept of research and development management. problem statement. Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 178-184. The subject of this article is the statement of the problem of creation of a new organizational-economic concept of the defense article research and development contract management system that take into consideration the features of research and development and that provide the recovery of the research-and-production potential of defense article developers and manufacturers and that corresponds with the idea of the partnership between private company and state. The article shows that the new organizational-economic concept of the defense article research and development contract management system should be based on the new organizational-economic approaches of the state customer to the setting of the pricing condition, funding conditions and production-property conditions of defense article development beyond the legal space of work and labour.
The possible term and funding risks of the general contractor is not taking into consideration. Strict fixation of the term and costs of the research and advanced development steps makes the contract development management system inflexible.
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Gindrankov V. V., Hariton V. A., Dvornikov I. V., Gres A. V. Scientific-methodical approach to the formation of the Сomprehensive plan of research in the part of the state aviation in the framework of «The national development plan of science and technology in the aviation industry until 2025 and the subsequent perspective». Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 168-177. Proposed and implemented in practice the scientific- methodical approach to work to develop a Comprehensive plan of research in the part of the state aviation in the framework of the National development plan of science and technology in the aviation industry until 2025 and the subsequent perspective (further the National plan) allowed joint decision representatives of enterprises and organizations of the aviation industry, theResearch Organizations of theRussian Defense Ministry:
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Kaloshina M. N., Ermakova O. V. . Aerospace MAI Journal, 2014, vol. 21, no 3, pp. 185-191. Funding research and development (R&D) in aerospace industry is associated with such uncertainties as the value of work and the achievement of specified technical, technological, financial and economic results. Securitization could be used as an insurance method. Securitization is assets funding by means of issuance of derivative securities based on some pool of assets.
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Shved Y. V. A way to increase the efficiency of use of the soft wing area in gliding descent and powered flight systems. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 7-12. The paper considers the ways of increasing the efficiency of lifting area of the soft wings, which are used in the gliding descent and powered flight systems, via engineering solutions. These approaches are based on making the wing rotate about the horizontal axis of the craft and thus create a rotation lifting surface. This way makes it possible to reduce required wing area by more than twice. At that the distinctive features of the «rotoplan» configuration, which is created on the basis of a soft wing, would allow the designer to avoid the known drawbacks of the existing cyclogiro configurations.
The vigorous cyclic variation ofthe setting angle and camber ofthe wing during the rotation can create propulsive force and thus support the wing rotation onits own. Itcan also allot the function ofthe propulsive device tothe soft non-rotating wing. The soft wing with blowing-type boundary layer control onthe upper surface near the point ofinflection (change ofthe curvature radius) ofthe profile has shown the best lift performance athigh profile camber. Atthat the blowing-type boundary layer control isimplemented bythe appropriately shaped slot inthe abovementioned area ofthe wing [5]. Installation ofvortex generators (inthe form ofstripes sewed onthe shell) inthe area ofinflection can help tomove the beginning (border) ofthe stall region into the area ofhigher camber ofthe wing profile. Due tothe cyclic action ofthe rotary wing onthe aircraft itisproposed touse such wing for unmanned vehicles. The UAVs, which are built according tothe described principle, can prove effective for carrying out reconnaissance and strike missions due tothe increased maneuverability and low noise ofthe propulsion system.
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Maslov G. A., Mitenkov V. B. Evaluation of the aircraft vibration characteristics using high-torque statistic in the case of limited experiments. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 13-17. During the flight in the process of separation of aircraft moving mass as a rule the high dynamic loads appear on the aircraft, its equipment and construction elements of small systems on board. As an avionics on aircraft board can be instrumentation equipment, control systems and small-sized engines. As a result of the flight and ground experiments the question of received data processing with unconventional ways arises. In this paper the construction of empirical laws of vibration loads distribution is proposed by using high-torque statistics.
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Sova A. N., Mazlumyan G. S., Baryshov D. P., Borisov R. B., Rulev S. V. Application of magnetic fluid technical means in processing equipment and technical systems of missile and space-rocket systems. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 18-31. Magnetic fluid (MF) technical means have very important property — they are controlled, so they spread in pneumatic, hydraulic, electric, electronic and other types of technics as a working body, in which the magnetic liquid changing the rheological properties (magnetization, viscosity and density is applied; electric, optical, acoustic, etc.) under the influence of an external magnetic field is used. Now three main types of MF are known: ferrofluids, magnetorheological suspensions and magnetic compositions.
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Zagovorchev V. A., Rodchenko V. V., Sadretdinova E. R. Selection of the lunar penetrator parameters with a through channel. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 32-40. Penetrator is an impactive ingrained probe, which is placed into the soil and used for study on internal structure of celestial bodies. The peculiarity of the concerned penetrator is a solid-fuel propulsion system with a straight-through channel, which allows a rational mode of penetration by reducing the resistance forces arising in the ground.
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Oleynikov I. I., Pavlov V. P. Estimation of domestic radar station and optical-electronic systems contribution into automatic system designed for preventing dangerous situations in outer space. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 41-48. At the present moment the basis for automatic system designed for preventing dangerous situations in outer space (Russian acronym «ASPOS OKP») is created in MCC TSNIIMASH under the aegis of Roskosmos. The main task of the system is collision warning between spacecraft and space objects (SO).
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Tkachuk A. V., Kozubski K. N., Rumyantsev А. V. Propulsion system with stationary plasma thrusters aboard small spacecraft. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 49-54. This article is devoted to the decryption of the Correction Propulsion System (CPS) named «ЭОЛ- 2010» developed on the base of the low power stationary plasma thrusters (SPT). This device is dedicated to power the low mass spacecraft keeping its working orbit parameters during active lifetime and de-orbiting after expiration. The CPS relevance is dedicated by increasing of the micro-satellites application in the various fields of science.
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Samokhin V. F., Moshkov P. A. Research of acoustic characteristics by vilga-35a light propeller aircraft on level flight conditions. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 55-65. This work is devoted to the noise problem of light propeller aircrafts. In the article the experimental obtained basic results of acoustical characteristics by light propeller aircraft (LPA) of Vilga-35A in flying conditions are presented. Spectral and power characteristics of LPA power plant (PP), acoustical radiation and also directional characteristics are recorded.
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Kolesnikov A. V. Prevention of defects in the process of superplastic forming and diffusion bonding sandwich panels of titanium alloys. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 66-74. The experience of production of sandwich panels from titanium alloys via a method of superplasticforming and diffusionbonding (SPF/DB) shows that in the process of forming under certain conditions there are defects. The defects arise as a result of bending sheet of panel in excess of certain critical value. The bend of a sheet of the panel in the process of forming occurs in a free zone of the bottom sheet between diffusive welding of the next edges of the panel. The size of a bend of a forming in a free zone depends on a material of the panel, a mode of forming and a design of a filler panel.
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Petrova L. G., Belashova I. S., Alexandrov V. A., Demin P. E., Brezhnev A. A. The possibility of obtaining of nano-modified layers and coatings on steel products by surface engineering methods. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 75-82. The article investigates the possibility of modifying the surface to form a nanostructured layers and coatings in metal materials and contains some specific examples of successful implementation of the objectives of nanostructuring of the surface layer in a metal surface by engineering techniques using various sources of thermal, chemical, heat treatment, physical or combined effects. In this investigation the possibility of obtaining the dispersion-hardened layers or coatings for forming a three-dimensional type of nanocrystal is realized: namely, in micro-sized (thickness of the order of tens or hundreds of microns) layer structure of a matrix solution with dispersed nanosized precipitates of secondary phases is formed. Carbides, nitrides and borides are such nanosized phases in our scientific paper.
Such combined surface engineering techniques involve a combination of thermal effects (chemical heat treatment, annealing), chemical exposure (doping, coating deposition) and physical effects (plasma, laser treatment).
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Vazhenin N. A. Characteristics of timing recovery in the conditions of joint influence of stochastic pulse noise and awgn. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 83-97. The analysis of effect of a random impulse noise on characteristics of space communication timing recovery systems is carried out. With usage of simulation models, characteristics of statistical equivalents of timing recovery discriminators in the conditions of joint effect AWGN and a random impulse noise are determined. The received results can be used for design and the analysis of the noise immunity property of the space communication systems functioning at effect of the given aspect of pulse noise.
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Kuprijanov A. I. Information counteraction for self-guided missile radio systems. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 98-103. In the article, the problem of the organization of counteraction to ignorance of anti-radar missiles on a source of radiation of electromagnetic waves of a radio range is considered. Counteraction provides statement of active misinforming interference radiated from the point of space which is not coinciding with the position of protected radio station. Synthesis of the parameters influences of interference is made with use of differential game model. By results of definition of optimum strategy for antagonistic players: coalitions of the director of interference both protected system on the one hand and a self-guided missile on another are defined requirements to parameters of the interference maximizing the minimum prize of system of counteraction. It is shown, that such interference should be coherently connected with parameters of the signal radiated by protected system. Thus, the interference should have double frequency and peak manipulation which should provide periodic change of level of the received signal in the antenna placed on the head of the missile. In one half- cycle, the interference should exceed level of inadvertent radiation in side lobes of the radiation pattern of protected radio means. In other half-cycle interference level should be below radiation level in side lobes. The period of peak manipulation should be equal to the distinction of interference frequencies and the signal of protected radio means. In the actual conditions of the withdrawing simulating interference with the parameters defined on the basis of the differential game decision, the kinematic trajectory — which is aiming in essence — shows the analysis of modelling results of missile movement which leads to the miss. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vazhenin N. A., Kirianov I. A. Software implementation of decoding low-density parity-check codes in MATLAB/SIMULINK. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 104-113. The purpose of the work is to increase the simulation speed of decoding low-density parity-check codes and to reduce the memory requirements for storing check matrix and array of variable and check nodes. Simulation speed increases through the use of low-level language which is introduced into a Simulink model by means of S-function approach. In this work, C language is used. The gain compared with the MATLAB language is 20 times. Moreover, low-density parity-check matrix contains mostly zero elements which are not involved in the decoding but require a lot of memory. This paper proposes a method for storing positions of only nonzero elements and the number of units in each row. This measure has reduced memory consumption in 100 times; in addition to it, small internal arrays can increase the processing speed.
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Starovoitov E. I., Zubov N. E. Analysis of the possibilities of onboard optoelectronic systems designed for the space objects rendezvous parameters measurement within the task of air vehicle orientation determination with the small angles start. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 114-128. During the start of various purposes air vehicle it is necessary to determine their orientation within the small deflection angles (from a few to tenths of a degree). Radio devices do not provide the required accuracy of measurement and the use of satellite navigation systems (GLONASS, GPS) on board of certain types air vehicle is not always advisable. To solve this problem it is proposed to use optic-electronic systems (OES) designed for space technology, which include laser radar systems, laser beacons and cameras. Equipments of this type can be used in the field conditions and not only in the special test areas. A review of OES main models is performed. These models are used to determine the orientation of spacecrafts during rendezvous and docking, and their basic technical characteristics including precision measurement of the deviation angles are provided. The use of OES active type (laser radar systems) and the installation of optical response devices on the air vehicle (check points — corner reflectors or laser beacons) to
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Russkikh S. V. Determination of initial conditions for the problem of aircraft dynamics after its lift-off from the elastic rail beam. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 129-138. Problems related to the movement of the aircraft or missile on the sliding bearings along the elastic rail beam arise at the present time in aviation engineering. For example, the launch of modern unmanned aircrafts in some cases is carried out by the rails.
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Antufiyev B. A., Konovalov A. V. Dynamics of the long thin-walled structure with a local damaged thermal isolation. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 139-145. Most heated aircraft units are protected by thermal isolation. Isolation prevents structure from overheating. However, sometimes isolation could be locally destroyed. After that, discrete temperature field can appear in primary structure of the aircraft. It leads to a transient structure deformation and stresses. Also destroyed isolation has lower mass and it can affect the dynamic properties of aircraft thermal protection. All this factors are reasons for accident with space shuttle «Columbia». In fact, the thermal protection is covered on internal pipelines of aircraft. Pipelines isolation destruction leads to the unpredictable consequences. Therefore, dynamic behavior research on aircraft primary structure with local destroyed isolation has practical use.
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Markov Y. G., Mikhailov M. V., Larkov I. I., Rozhkov S. N., Krylov S. S., Perepiolkin V. V., Pochukayev V. N., Filippova A. S. Fundamental components of Earth orientation parameters in satellite navigation problem. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 146-157. Purpose
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Safonov A. I. Influence of viscous friction on stability balance of the body with a vibrating suspension. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 158-168. Influence of high-frequency vibrations on stability of stationary motions of mechanisms used in aviation and cosmic techniques is a very actual problem. Vibrations can change the nature of stability and cause new dynamic effects. Furthermore, friction should be taken into account when studying real systems.
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Myltcina O. A., Belostochny G. N. Thermoelasticity of the reinforced plate under influence of quick change for coordinate of thermal and force factors on the boundary. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 169-174. On the base of the Love model and the classical Fourier thermoconductivity theory the analysis of the thermoelastic behaviour of the geometrically irregular plate is carried out. Two opposite edges of the plate are exposed to quick change in temperature fields and force stress on space coordinate. Such temperature fields and force stress are described as multiplication of suitable functions by the Heaviside function. These functions at force stress points, when the Heaviside function is not defined, become zero along with their derivatives until the required order.
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Kozelkov O. A. Mathematical modeling of multystage technological process. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 175-180. Subject of study in the article are models and methods of analysis and evaluation of functional parameters of successive line production process. The aim is to assess the technological feasibility of the planned production processes through the analysis and consideration of the characteristics of individual process steps and equipment used.
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Komarova N. V. Development strategy of the helicopters enterprise based on competence centers. Aerospace MAI Journal, 2014, vol. 21, no 2, pp. 181-186. Purposes
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Shydakov V. I., Zavalov O. A. Selection of fenestron design parameters. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 7-13. The paper presents the analysis of the available power consumption by the fenestron in different flight modes as well as the analysis of the change of the single-rotor helicopter weight with the installation of the fenestron. The analysis aims at determining the values of the design parameters of the fenestron and evaluating the rationality of its use on helicopters of various weight categories.
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Ermakov S. A., Obolensky Y. G., Sukhorukov R. V. Power supply of aircraft flight control actuators in case of all propulsion engines failure. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 14-24. The paper reviews a possible solution to the problem of power supply of the actuators of the main flight control surfaces, which ensures the safe controllable flight of a passenger airplane in case of failure of all of its propulsion engines. In this critical emergency situation the performance of the main sources of the hydraulic power degrades and the flow of the hydraulic fluid, which is generated by the pumps, approaches zero. If the propulsion engines can enter the autorotation mode, the process of degradation of hydraulic power to supply hydraulic power to the actuators of the main flight control surfaces. Such power supply could be combined with the power of the emergency ram-air turbine, which transforms the ram air energy into the hydraulic power by means of a turbo-pump unit.
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Bakulin V. N., Kokushkin V. V., Borzykh S. V., Voronin V. V., Shchiblev Y. N. Research on the landing surface ground properties influence on a stability of the space vehicle landing process with a mechanical landing device. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 25-32. Stability of one difficult space systems functioning key stages is investigated. This is a process of spacecraft landing on a ground. Essential residual spacecraft kinetic energy dissipates at a direct contact to a landing surface. The vehicle is supplied by a multi-supported landing gear of lever type, because for reusable spacecrafts the requirement of an exception of its body impact with a ground is obligatory. The approach to modeling is based on that the vehicle body and its landing gear elements are considered as a structurally-difficult mechanical system with the intercommunications which character reflects the design features of landing gear support. For each body the displacement equations of the centre mass and the rotation equation about centre mass are recorded. Besides, the special system of the equations for joints reactions definition between bodies consisting system is made. Stability in activity is understood as an overturning absence from the landing gear support of first contact moment to a surface to vehicle full stop. Character of motion is appreciably determined by landing surface properties which should be considered for reusable spacecrafts in a broad band, i.e. from the soft dry sand structures to the heavy frozen ground. The elastic-viscous interaction model of support landing gear scuff plate with a ground based on Voigt hypothesis is developed. The support element is a spherical segment for which ground reaction on a normal to the surface is determined as a function of geometrical segment parameters, depths and speeds of its introduction into a ground and landing surface deformation characteristics. Lateral reaction (at a tangent to the surface) is determined by means of the generalized drag coefficient to horizontal displacement considering the friction forces of steams «scuff plate -ground» and ground displacement along the surface. The parameters rendering influence on a landing stability are revealed. There is a spacecraft angular velocity at the first contact moment to the surface, speed of its centre mass, spacecraft orientation to landing surface, landing surface slope and ground characteristic. The analysis has shown that for stability maintenance the landing case of a soft sand ground is critical. Stability zones for parameters of center mass horizontal speed component and landing surface slope angle for the set of other initial parameters that characterize the normal («regular») landing conditions are constructed. It is shown that initial parameters which can be provided by a spacecraft control system lies in stability areas. Some solutions which can provide landing stability even at determined deviations from regular landing conditions are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bobronnikov V. Т., Trifonov M. V. Technique of the statistical analysis of 1st stage lv motion taking into account random wind loads. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 33-42. Scope of research
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Petrov D. S. Spacecraft propulsion system simulation using three-stage decomposition method. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 43-57. Simulation is well known and highly used instrument for majority of space mission control tasks. Special software tools are used for development of spacecraft simulation models. These packages consist of a number of simple elements and algorithms designed for such elements synthesis. But some disadvantages were found in existent tools. The article is devoted to the new simulation models development method without such disadvantages. This method is based on structural decomposition into the simple models with one or a few short equations.
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Konstantinov M. S., Orlov A. A. Optimization of low thrust trajectory to the jupiter flight with two gravity assists near the earth. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 58-69. Subject
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Bondarchuk P. S. Resonant steering electric drive. simulation of operating cycle. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 70-75. The resonant electric steering drive (RESD) can be applied as a part of control systems of all classes of rockets rotating on a list. Existing samples of RESD still far from perfect and their weight and dimensions are redundant. The purpose of this work is receiving a quantitative assessment of weight surplus of the best sample of RESD known now. In the course of work the problem of receiving a quantitative assessment of a stock of power and weight of the executive engine (EE) is solved. EE is the basic element of the drive defining its specific characteristics. Research is conducted by method of modeling of an operating cycle of the hypothetical guided missile. In this paper the questions of creation of the RESD imitating model which takes into account the thermal processes, occurring in EE and its research are considered. The model is created in the environment of Simulink entering into a mathematical MATLAB package. Models of entrance influences of the drive changing in time and loadings of its output link are constructed. The power stock of the EE was estimated at temperature of an overheat of windings and on energy of losses. The simulation results showed that the power of the EE in more than 10 times greater than those required output. It confirms that samples of RESD existing now possess the big excess weight and dimensions which can be significantly reduced at the expense of decrease in weight and dimensions of EE. The obtained results allow to carry out works in the direction of definition of extremely achievable specific characteristics of the steering drive at the present level of technology. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Melnikova G. V., Shorr B. F., Sal'nikov A. V., Nigmatullin R. Z. Automated dynamic optimization of the blades of the gas turbine engines. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 76-85. This paper is about the method of turbo machinery blades dynamic optimization. The method allows receiving the necessary dynamic characteristics of the blades taking into account long-term static strength and requirements of gas dynamics and structural constraints.
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Zinenkov Y. V., Lukovnikov A. V., Cherkasov A. N. Technical shape formation of power plant of high-altitude unmanned aerial vehicle. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 86-94. Purpose of the work is development of mathematical model (MM) of calculation of thrust-economic and weight-dimension characteristics of power plant (PP) for the unmanned aerial vehicle (UAV) with a turbojet.
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Kim V. P., Merkur'ev D. V., Sidorenko E. K. Investigation of plasma and radial ion flow parameters in the vicinity of the spt exit plane. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 95-103. Results of the plasma potential, temperature of electrons, radial ion flow density and ion energy experimental study in the vicinity of the stationary plasma thruster (SPT) model exit plane are represented in this paper. This SPT model with external accelerating channel diameter of 85mm was developed at RIAME MAI and operated with discharge voltages of (300-800)V and mass flow rates through the mentioned channel of 2.1mg/s and 2.5 mg/s of Xenon. Plasma parameters were measured by several flat electrostatic probes positioned in the vicinity of the thruster exit plane along different radial directions and at the same distance fr om the thruster axes corresponding to the typical distance of cathode position from the mentioned axes. Energy of ions in the vicinity of thruster exit plane was measured by the retarding potential analyzer (RPA). It is shown that character of the plasma parameter dependence on the discharge voltage changed significantly with the increase of the mass flow rate through the thruster accelerating channel from 2.1 mg/s to 2.5 mg/s and that the mean energy of ions was around (80-120) eV and weakly dependant on the discharge voltage within the range of the discharge voltages of (300-800) V. Thus, energy of ions in radial ion flows moving in the vicinity of the thruster exit plane is sufficient to sputter structural elements such as cathode.
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Potapov S. D., Perepelitsa D. D. Research of influence of residual tension in the zone of the arrangement of the crack on the rate of its growth at cyclic loading. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 104-110. With use of special samples simulators pilot researches of growth rate of a crack in the conditions of action of the residual squeezing tension which size is characteristic for the high-loaded details of aviation engines are conducted. On the basis of the settlement pilot studies including definition on models of high level of intense of the deformed condition of special samples simulators with cracks and definition, by means of a fractography, a step between grooves, the kinetic charts of growth rate of a crack in a material of special samples in the conditions of action of residual compression stresses tension are received.
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Novikov V. F., Kartashova A. A., Usmanov N. T., Taneeva A. V. Study of properties of the liquid-crystal sorbents for gas chromatography. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 111-115. Nowadays in gas chromatography more than 2000 different sorbents are used. Trey are prepared on organic base and inorganic compounds. In gas chromatography liquid-crystal sorbents are used for the Trey are prepared on organic base and inorganic compounds. In gas chromatography separation of positional isomers. It is known that the selectivity of separation of the positional isomers is largely dependent on the structural characteristics of the liquid crystal molecules and the presence in sorbent of the different functional groups with different physic and chemical nature. In article studied a number of liquid crystal 4- alkoxycarbonyloxy-4’- natroazoksibenzols. The values of logarithmic and linear retention indices of standard sorbates are shown. For the investigated series of compounds even-odd effect is observed. While for odd substituents are characterized by higher values of retention indices that than even. Methyl radical behaves abnormally, which contributes to a sharp decrease in the values of retention indices for all standard sorbates. Assuming that a methyl group, possessing electron-donating properties, contributes to a significant change in the electron density at the nearest oxygen atom in molecule azoxybenzenes and escapes his lone electron pair. As a result of the intermolecular interaction energy of polar sorbates weakened, resulting in a decrease in the values of their retention indices. Three areas of changing of retention sorbates under the action of temperature are founded. They are areas of the isotropic liquid, the liquid crystal and solid crystalline states. There is a separation of para- and meta-xylenes which selectivity of separation varies depending on the temperature conditions of the process of chromatographic separation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vazhenin N. A. The analysis of noise immunity of the quadrature compensator of impulse noise. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 116-123. Modern and perspective space vehicles (SV) widely use electric rocket engines (ERE) for an attitude control and space vehicle orbit correction as well as in the capacity of sustainers. As it has shown probing, under certain conditions data ERE except thermal noise radiation can form radiation in the form of a random pulse sequence in microwave band.
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Damaratsky I. A. Evaluation of reflection cross-section simulation CST Microwave Studio accuracy for geometrically typical objects. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 124-134. The aim of work was to evaluate CST I- and CST А-Solver module accuracy for calculating reflection cross-section (RCS) of objects with typical geometric form. The methodology of accuracy evaluating comprised: experimental measuring of RCS angular diagrams for work objects, diagrams calculating in CST I- and CST А-Solver, calculating of deviations between calculated and experimental diagrams per ranged characteristic coefficients, root-mean-square errors, average relative errors. Ranged characteristic coefficient characterized linear dependence degree between compared diagrams and ensured root-mean-square error and average relative error to be good evaluation of CST accuracy. In the work, it was supposed, that errors are good evaluations, if ranged characteristic coefficient value is equal or bigger, than 0.7. The work was executed for electromagnetic wave (EMW) with following frequencies: 2, 3, 4, 8, 10 GHz; both horizontal and vertical EMW polarization was considered to make the investigation complete.
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Malachov R. Y. Digital antenna array power amplifiers for on-board radioelectronic systems. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 135-142. This article describes the problem and the current state of the transceiver modules (TM) of active phased array antenna and digital antenna arrays (DAA), as the next stage of their development. Structure of the DAA in which TM consist of highly stable grid frequency synthesizers synchronized by digital reference generator was considered. Exception complex microwave wiring and traditional phase shifters change on digital devices beamforming (quadrature modulators) requires substantiation requirements for hardware components. Particular attention is paid to the frequency range from 4 to 12 GHz.
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Bukhalev V. A., Boldinov V. A., Pryadkin S. P. Recognition and evaluation of the output signal of a nonlinear system in the conditions of intermittent interference simulation. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 143-153. The aim of this work is to develop robust algorithm of recognition and estimation of input signals in conditions of action of random intermittent interference with the spectral density close to the signal. Transient processes occurring in the system due to the sudden, unexpected and usually poorly observed changes jamming environment, require some time for their recognition and response. Consequently, as the methodological basis of the algorithm recognition and estimation of the input signal is advisable to use the apparatus of the theory of systems with random jump structure (SRJS) in the class of Markov mathematical models, Bayesian information processing and method two-moment parametrical approximation (TMPA). TMPA technique consists in approximation of the unknown laws of distribution of a signal and interference by the known laws of unknown mathematical expectation and the covariance matrices that allows constructing the approximate optimal algorithms, combining well accuracy with the ease of implementation in computational devices of unmanned aerial vehicles. Optimization of the algorithm of recognition and estimation of the useful signal is carried out using Bayesian approach and double-stage parametric approximation of a posteriori probability density signal beta distribution. Appropriate quality of the algorithm is proved by the results of modeling of its work, which showed that, despite the close resemblance of the true signal and noise, the presence of a number of erroneous meter readings and indicator patterns, signal estimation and evaluation of the structure are quite close to the estimated variables. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alekseev V. A., Kudriavtseva N. S., Titova A. S. Heat chamber parameter choice for nonpressurized earth satellite antenna array thermal tests. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 154-162. Theoretical and experimental approach for heat chamber parameter choosing for thermal tests of active phased antenna array digital radar module operating on nonpressurized Earth satellite is discussed. The suggested approach includes three theoretical and experimental steps. At the first step the digital radar module thermal behavior is tested in heat vacuum chamber that most closely simulates the environmental conditions of the nonpressurized Earth satellite. At the second step mathematical simulation of the digital radar module heat processes in heat chamber is carried out. At the third step the algorithm is developed and the heat chamber parameters are chosen providing the digital radar module temperature field in the heat chamber identical to the temperature field of the same module in the heat vacuum chamber. The criteria of the heat and heat vacuum chambers thermal conditions identity is the criteria of minimum mean square error of the digital radar module temperature fields in the both chambers under the heat release sequence diagrams given in Technical Requirements Specification.
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Kozlov A. V., Sharonov A. V. Geometric dilution of precision factors in gps/glonass carrier phase ambiguity resolution in attitude determination. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 163-168. The paper considers determination of an aircraft position using the processing of carrier phase satellite radio navigation signals from several GPS/GLONASS (below referred to as global navigation satellite systems — GNSS) antennas mounted on the fuselage. The specific point of carrier phase measurements is phase ambiguity which makes it impossible to obtain attitude solution estimate using the measurements only at one instant of time. So, measurements from a certain interval of time are used to make the estimate consistent. The desired attitude parameters and phase ambiguity become observable due to the motion of the GNSS satellites constellation. The accuracy of attitude determination naturally depends on the accuracy of phase ambiguity resolution, which in turn severely depends on the constellation kinematics. These relations are under the study. The paper gives an approach to a priori accuracy of phase ambiguity resolution.
where tr() is the trace of the matrix , is estimated error covariance of ambiguity resolution, is a reference noise level and n is number of measurements. Positional dilution of precision factor PDOPCK is much like the same except for positional covariance matrix is used in formula. The higher the value — the less accurate estimate is produced, and vice versa. Processing of a survey data shows that every time phase ambiguity has an outlier, there is a leap in ADOPCK. This fact indicates that there is a real connection between new introduced quantities and phase ambiguity estimation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y., Moskalenko O. A., Pirumov U. G. Numerical simulation of stationary waves of combustion and detonation in kerosene-air fuel mixture. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 169-177. The object of research Stationary waves of burning and detonation in kerosene — air gas-droplet mixture Theme Numerical simulation of combustion and detonation in combustible gas — drop kerosene — air mixture Purpose The article is considered with the development of a simplified physical-mathematical model of the combustion-detonation process of gas-droplet kerosene- air mixture; numerical simulation two problems: self- ignition of the combustible mixture for a shock wave traveling with a constant velocity along the duct and mixture dynamics after the injection of particles in high- temperature air flow. The method of investigation Numerical simulation Results We present the physical-mathematical model, computational algorithms and software for numerical simulation of self-ignition of gas-droplet kerosene- air mixture for a shock wave extending with a constant velocity in the duct (the detonation wave (DW)) and after injection of particles in high-temperature air flow (burning wave (BW)). In our study the kerosene was considered as unicomponent «gross matter» that evaporates and is involved in gas-phase chemical reactions. Processes occurring in the gas phase were considered in three formulations: «equilibrium» — was considered that chemical reactions occur in equilibrium; «nonequilibrium-reversible» and «nonequilibrium-irreversible». For two latter formulations the chemical transformations described gross mechanism in which all reactions are considered reversible and part of reactions are irreversible respectively. We studied the influence of the mass fraction and the initial droplet diameter on the structure of waves of burning and detonation. Minimum velocity of detonation and the maximum velocity of the air were obtained using computational methods for this formulation. According to the results, there are stationary regimes in the stream. It is shown, that using traditional «non-equilibrium- irreversible» model may lead to inaccurate estimates of heat emission during burning and detonation (Fig. 1). At the same time, the trajectories of processes in the phase plane of «specific volume-temperature» (Fig. 2) end at the equilibrium adiabat for «equilibrium» and «nonequilibrium-reversible» models, but not for «nonequilibrium-irreversible» model. The developed physical-mathematical model and computational algorithms are used as an element of techniques for simulation of burning and detonation of kerosene-air mixture in the multidimensional formulation. Fig. 1. The temperature distribution in the DW (). Models: 1,2 «equilibrium»; 3, 4 «Nonequilibrium reversible»; 5, 6 «Nonequilibrium irreversible»; 1, 3, 5 initial droplet diameter =10 microns, 2, 4, 6 = 50 microns
б) Fig. 2. a) The change of temperature in DW (= 298,15 К), b) The temperature in the BW (= 1000 К) on the phase VT plane ( = 101325 Pa, = 50 microns): . Model: × «equilibrium»; «nonequilibrium reversible»; solid line «nonequilibrium irreversible» (ДА equilibrium adiabat, УА shock adiabat)
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Gutenev A. V., Panchenko I. N. Analysis of the geography of the regional jet aircraft world market, based on the data from the customer base of the airlines. Aerospace MAI Journal, 2014, vol. 21, no 1, pp. 178-191. This article discusses the current state of the regional jet aircraft world market in terms of the major players customer base regional analysis — «Embraer» and «Bombardier», as well as the prospects of domestic products in this class — SSJ- 100 aircraft.
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Shydakov V. I., Zavalov O. A. Numerical modeling for parametrical study of fenestron geometry on the basis of energy analysis. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 7-16. The problem of selection of fenestron design parameters consists in finding such a combination of geometrical parameters of the fan, inlet and diffuser within the given overall dimension of the fenestron, which would provide the least possible power consumption of its fan at the given thrust value. The varied design parameters (parameters, which act as design variables) include the following: the fan radius R, the relative curvature radius of the inlet the relative diffuser length . The overall fenestron dimension is determined by the suction (low pressure) area on the intake surface. This dimension can thus be calculated according to the following formula .
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Nesterov V. A., Semenov I. M. The geometric criteria utilization for safe cargo detachment from aircraft compartment process development. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 17-21. Increasing of both flight velocity and load factor range by cargo detachment can be used for modern aircraft needed performances insurance. As the result both aerodynamic and inertial forces acting on cargo increase during cargo forced motion as well as cargo flight into turbulent zone at the carrier vicinity. All above mention should be considered especially applying to relative light cargo detachment.
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Konstantinov M. S., Min T. . Optimal direct trajectories to the jupiter with nuclear electric propulsion. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 22-33. Subject
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Zhigastova O. K., Pochukayev V. N. Inspection procedure of an unmanned spacecraft flight plan using a simulation model of the onboard control complex. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 34-43. Purpose
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Kostev Y. V., Matveev Y. A., Pozin A. A., Shershakov V. M. Methodical apparatus for rocket experiment designing. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 44-52. This paper considers a methodical apparatus for the rocket experiment designing; the peculiarities of problem statement for the rocket experiment designing and the algorithm of complex coordinated parametric optimization of technical means involved in a rocket experiment are discussed. Ratios for assessing RE efficiency at an early stage of development as well as comparative assessment of suggested RE facilities are presented.
The ratios for assessing RE efficiency are given. The efficiency of rocket experiment depends on the perfection of technical means, on the progress of tool- management and information-methodical support system. There are two groups of problems under consideration: one can be solved with the help of RRC, i.e. problems solved by direct rocket measurements, and problems solved by ground measurements of those effects in the atmosphere and space that are generated by devices installed on rockets.
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Lamzin V. V. Research on space system realization condition indeterminations influence on performance factors dispersion. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 53-65. This article deals with questions of taking into account indeterminate and random factors during the space systems of Earth remote sensing design (SS ERS). In general there are indetermination of functional connection, project realization condition of SS ERS, demands to performance factor value targets indetermination). As it is shown fr om analyses an accounting of indeterminations and random factors as well as indetermination of working models and methods allows to attack a problem of estimation and selection of project decisions, take into account possible dispersion (loss) of quality. The methodology for influences investigation of realization condition indeterminations of perspective spacecraft (modification) as a part of SS ERS with indeterminations of engineering-and- economical models is proposed. During the methodology development the enlarged typical structure of SS ERS, which includes two main subsystems — space and terrestrial segments, was considered. It is assumed that existed facilities of terrestrial segments with known parameters are used and this article is devoted to parameters selection of perspective spacecraft as a part of SS ERS with modernization by given time period and risk estimation during system project realization. There is optimization (estimation) problem statement of perspective spacecraft (modified spacecraft) as a part of SS ERS with modernization by given time period. The peculiarity of this problem statement is multicriteriality, it allows to estimate main performance indexes as functional system effectiveness, cost of project and labor intensity (framework) with taking into account indeterminate factors (connections). In parallel the possible risks (losses) during SS ERS project realization are estimated. Averaged risk should not exceed given lim it. In project models using for investigation of perspective space vehicles (modified spacecraft) there are outlined determinative parameters, which values depend on project realization time. As an example of these parameters there are coefficients of monetary and mass correspondences. As the coefficient of monetary and mass correspondences are defined based on experimental (statistical) data, then according to experimental data change (with taking into account scientific-and- technological advance) the coefficients change. Coefficients are random values and have dispersion. Investigations of space system ERS realization condition indeterminations (project realization period duration, injection type, ratio between development cost and vehicle creation, quantity of spacecraft in system) influence on dispersion of summarized given cost during the system modernization within planned period are carried out. Method of statistical modeling is used during the estimation of engineering-and-economical characteristics of space system project with condition indeterminations of project realization. With the given quantity of statistical tests the rational (optimal) value of averaged costs (statistical expectation) and its dispersion (mean square deviation) are determinated. Investigations results are presented and analyzed. For example, analyses of mean square deviation value of presented summarized costs (project realization risk) shows, that increasing in amount of random values (coefficient of monetary and mass correspondences) and forecast interval leads to increasing in project realization risk. Research results can be used not only during the perspective space vehicles development, but also during the development program correction of existed SS ERS as well as during the determination of demands to perspective space vehicles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolichev I. A. Optimization of the multirevolutional non-coplanar low-thrust orbital transfers. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 66-76. Subject
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Nesterov V. E., Rudakov V. B., Makarov M. I. Development test objectives analysis of reusable space rocket system. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 77-85. Paper considers the Reusable Space Rocket System (RSRS) developed by the Khrunichev State Research and Production Space Center. The system includes Reusable Space Launch Vehicle (RSLV) and the ground complex facilities.
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Lovtsov A. S., Selivanov M. Y., Belikov M. B. Study of the influence of azimuthal magnetic field nonuniformity inside the discharge chamber on the ion thruster performance. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 86-95. Configuration of magnetic field in the discharge chamber of ion thruster is traditionally considered in the axisymmetric approximation. This approach is reasonable for the thrusters with permanent magnet rings (ring cusp thruster). However, as it is shown hereinafter, the Kaufman thrusters using magnetic systems with electromagnets placed around the discharge chamber periphery have significant azimuthal nonuniformity of magnetic field. This nonuniformity can lead to the reduction of magnetic field capability to confine electrons from direct loss to the anode. There are two reasons of such reduction. First, magnetic field has too low strength in the regions between magnetic coils to confine electrons efficiently. Second, new mechanism of electron drift appears in the nonuniform magnetic field.
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Khayrnasov K. Z. Simulation of stamping process of aviation engines parts. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 96-104. In the article, the methodology and algorithm of the process of deformation of the shell under the action of dynamic pressure in general case of a variable over the shell surface are considered. This algorithm can be applied for the shells of rotation of an arbitrary shape. Such problems appear during the shaping of the shell- type structures from the flat plates.
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Agamirov L. V., Agamirov V. L., Vestyak V. A. Development of an algorithm for estimation of the parameters of the distribution function of the limit of endurance at fatigue tests. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 105-110. One of the ways of representing characteristics of fatigue resistance of materials and structural elements is the distribution function of the limit of endurance. It order to calculate structural elements, to conduct test planning and to perform statistical analysis of their results it is recommended to use the normal law of distribution , of the limit of endurance or the normal variable distribution (logarithmic normal where m — the number of levels of voltage amplitude distribution) [2, 3]. For steels Weibull-Gnedenko distribution of the limit of endurance is widely used. Statistical estimation of the parameters of the distribution function of the limit of endurance is performed by «up- and-down» and «probit» methods based on the maximum likelihood method (MLM), as well as by other methods.
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Vazhenin N. A. The analysis of joint effects of additive white gaussian noise and random impulse noise on information and synchronization channels of space communication radio link. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 111-123. Previous experimental researches showed there can be an impulse noise connected with an activity of stationary plasma thrusters (SPT) in space communication systems and also caused by static discharges in around object medium, effect of micrometeorites, etc. The analysis of joint effect of an additive white Gaussian noise (AWGN) and a random impulse noise on the characteristics of the immunity to noise of space communication radio systems is carried out. The analysis is performed taking into account effects of observed interferences both on the information channel, and on channels of phase and symbolical synchronization. Main principles of development and usage of imitative models of space communication radio systems are considered. Conducting of the modeling with usage of one of the following algorithms of symbolical synchronization is possible: Gardners algorithm, Gardners algorithm with wide gates, algorithm with leading and retarding time gating, square algorithm, algorithm M&M and algorithm of ideal synchronization. The system of phase synchronization on the given interval of a time executes an estimation of average shift of an arrival signal phase. With usage of imitative models for radio signal FBPSK, the dependencies of probability of a bit error on signal-to-noise and signal-to-pulse-noise ratios are determined. Effect of the pulse noise is essential to signal-to-noise ratios of about 10 ... 12 dB and signal- to-pulse-noise ratios smaller than 20 dB. Thus energetic loss at the expense of the pulse noise can affect from units to tens dB, depending on signal-to-noise and signal-to-pulse-noise ratios. An essential effect of timing recovery errors on the communication system noise immunity leading to energetic loss approximately in 1 dB is also shown. The received results can be used at designing stage for choosing the parameters of space communication systems and systems of timing and phase recovery; they can also be used to analyze the effects of impulse noise on the operation of space radio communication systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Knyazeva V. V., Neretin E. S. Algorithmic and hardware provision for onboard radar data processing devices. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 124-133. Purpose: promptitude improvement of the existing onboard data processing devices for object recognition in radar images based on the optoelectronic apparatus and artificial intelligence methods. Research methods applied in the work: methods of data processing in complex systems, artificial intelligence techniques, methods of analysis of parallel computing algorithms, experimental methods, and test and inspection methods for samples of data measuring and control systems. The structure of the onboard data processing device was developed. The structure includes the optoelectronic matrix multiplier performing parallel optical matrix calculations that improves its promptitude when recognition of objects in the radar image on a flat stage. The algorithmic component of the device comprises Software for realizing operation of the modified neural networks along with database of object images that are to be detected. The process of object recognition on a flat stage is carried out by the onboard data processing device iteratively. One-dimensional and two-dimensional bipolar models of the Hopfield neural network were modified. Both models are intended for use in the onboard data processing devices based on the optoelectronic matrix multiplier for pattern recognition. The algorithms that realize the modified bipolar model of one-dimensional and two-dimensional Hopfield neural network were developed for recognition of objects in the radar images on a flat stage in the onboard data processing devices. The algorithms are implemented in the form of Software «Hopfield neural network simulator for on-board equipment». The Software testing and using it for simulation of simple examples fully confirmed its operability and adequacy of modified neural network models in the onboard data processing tasks. Simulation using radar images obtained with synthesized aperture radar confirmed the efficiency of the modified Hopfield neural ! ВЕСТНИК МАИ. Т.20. № 5 network models for solving tasks of object recognition in radar images on a flat stage in noise conditions. Two level architecture of firmware complex was developed for testing algorithms and hardware of optoelectronic components and perspective onboard modules of data processing devices including usage of the Hopfield neural network. The firmware complex designed allows carrying out testing of existing and promising onboard data processing devices. Originality: The onboard data processing device structure based on optoelectronic matrix multiplier and Hopfield neural network was developed; One-dimensional and two-dimensional bipolar Hopfield neural network models were modified for implementation in the onboard data processing devices based on the optoelectronic matrix multiplier for recognition of objects in radar images on a flat stage; Algorithms realizing the modified one- dimensional and two-dimensional bipolar Hopfield neural network models were developed. Algorithms applicable to the implementation in the onboard data processing devices based on optoelectronic matrix multipliers for object recognition in radar images on a flat stage; Structure of firmware complex for algorithms and hardware testing was developed. It provides testing of optoelectronic components and modules of perspective onboard data processing devices based on neural networks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Martirosov V. E., Alekseev G. A. The software implementation of quasicoherent minimum shift keying demodulator. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 134-148. The aim of this work is to investigate the methods of quasi-coherent demodulation of minimum shift keying (MSK) signals and the creation of a software implementation of MSK demodulator. Minimum shift keying (MSK) due to its spectral and power efficiency has been widely used in systems with limited frequency and energy resources. MSK signal has a constant envelope and this is an important and sometimes crucial aspect for communication systems operating at low power, with thresholds values of signal/ noise ratio (SNR). In such conditions also often require the use of quasi-coherent demodulation algorithms, as they are compared with incoherent demodulation algorithms provide less error probability. The refore the development of efficient implementation of quasi- coherent MSK signal demodulator is an actual task. The article considered in detail procedure of quasi- coherent MSK signal demodulation including method of symbol synchronization establishing and algorithm of carrier frequency synchronization. Shows the structural schemes, spectral and times diagrams of signals at different points of the demodulation tract. Based on the considered algorithms is carried out to develop a software implementation of quasi-coherent demodulator of MSK signal for rapid satellites communication channel. Testing of the demodulator using the software stand has been performed. In modeling taking into account the actual conditions of reception, when the frequency of the input signal is shifted and in the transmission channel there exists an additive white Gaussian noise (AWGN). The simulation results indicate that the implementation of the demodulator is successful. The establishment of a high-frequency synchronization and symbol timing is within the required time, the flow of extracted information symbols corresponds to the transmitted message. To determine efficiency of the resulting implementation has been assessed probability of symbol error of demodulator in a specified range of values the signal/noise ratio. According to the research results the energy loss of the developed quasi-coherent demodulator does not exceed 0.5 dB with respect to the potential noise immunity. This demonstrates the high efficiency of the provided software implementation of quasi-coherent MSK demodulator. The obtained results argue the possibility of using the developed software model as a research prototype or stand for hardware and/or software implementation of the MSK demodulator in the satellites digital telecommunication system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bukhalev V. A., Boldinov V. A., Pryadkin S. P. Recognition and evaluation of linear system output signal under intermittent simulated interference. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 149-157. The problem of recognition and estimation of signal of the object in imaging and radio guidance systems for unmanned aerial vehicles in conditions of alternating receive true and false signals is discussed in the paper. The aim of this work is to develop a robust algorithm for recognition and estimation of input signals under conditions where random intermittent interference with the spectral density close to the signal is acting. Transient processes occurring in the system due to sudden, unexpected and usually poorly observed changes jamming environment require some definite time for their recognition and response. Consequently, as the methodological basis of the algorithm recognition and estimation of the input signal is advisable to use the apparatus of the theory of systems with random jump structure (SRJS) in the class of Markov mathematical models, Bayesian information processing and method two-moment parametrical approximation (TMPA). The latter consists in approximation of the unknown laws of distribution of signal and interference by some known laws with unknown mathematical expectation and the covariance matrices that allows constructing the suboptimal algorithms, combining both accuracy and easiness of implementation in computational devices UAV. The retrieved robust algorithm of information processing, based on the theory of SRJS, using Bayesian approach and two-moment parametrical approximation of the probability density of the signal with Pearsons distribution law. Simulation results of algorithm work showed, that despite the close resemblance of the true signal and noise the presence of a number of erroneous meter readings and indicator patterns, signal estimation and evaluation of the structure are quite close to the estimated variables that confirms good quality of the proposed algorithm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Benzerrouk H. -., Nebylov A. V., Salhi H. -., Closas P. -. «Cubature & gauss-hermite» based kalman filters applied to unmanned aerial vehicle attitude estimation problem. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 158-169. In this paper, description of modern direct filtering approaches in INS/GNSS integration are presented, Cubature Kalman Filter (CKF) and Gauss Hermite Kalman Filter (GHKF). Robust design of low cost IMU/GNSS is proposed to solve the problem of UAV attitude estimation problem based on multiple sensor fusion. Multiple GNSS antennas are assumed available to improve and increase the accuracy of satellite positioning system and observe attitude angles delivered by the IMU. Nonlinear approximation techniques such as Extended Kalman Filter (EKF), Sigma Point Kalman Filter (SPKF) and most recently developed algorithm Cubature Kalman Filter (CKF) with GHKF are tested in this work. Estimation accuracy compared with approximated Cramer Rao Lower Bound CRLB provided a classification of different nonlinear filters clearly deduced during multiple simulated state estimations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Borisov M. V., Zakharov M. A., Chernomorskii A. I., Chirkin M. V. Methods for determining the synchronization threshold of counter-propagating waves in a small-sized laser gyroscope. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 170-178. Abstract Different methods for determining the synchronization threshold of counter-propagating (STCPW) waves in a small-sized laser gyroscope (SSLG) are presented which allow to determine this parameter along all product life cycle and to minimize it during operation. Purpose The purpose of the paper is search for the most easy- to-realize, accurate, and convenient methods for determination of STCPW at all stages of product manufacturing and operation. Design/methodology/approach Prediction of the laser gyroscope STCPW value was carried out by analysis of mirror and mirror substrate surface roughness via atomic-force microscope. Measurement of this parameter was performed on the base of the following methods. 1. Measuring method of STCPW on the base of SSLG output information signal estimation against its angular velocity. 2. Measuring method of STCPW on the base of SSLG output information signal estimation against vibrating support oscillation magnitude. 3. Measuring method of STCPW on the base of algorithmic processing of SSLG output information signal. 4. Measuring method of STCPW on the base of analysis of SSLG scale factor dependence on its angular velocity. Minimization of this parameter during the operation period is performed by selection of the operating mode. The criterion for operating mode selection was value of modulation depth of radiation intensity at the difference frequency. Findings On the stage of incoming inspection of SSLG OEM components authors found out promising technique of prediction of the laser gyroscope STCPW value by analysis of mirror and mirror substrate surface roughness via atomic-force microscope. In respect to the SSLG assembly step authors demonstrated capability of SSLG determination on the base of algorithmic processing of SSLG output information signal as early as on the stage of electrovacuum processing of ring resonator for its performance evaluation. At the operation stage method of selection of the SSLG operating mode is rather promising for STCPW minimization. Originality/value On the base of analysis of existing methods of direct and indirect STCPW determination authors have developed the most promising methods of STCPW prediction and determination along all stages of SSLG life cycle. Principles of operation of measuring benches for STCPW prediction and measurement are described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pototskii M. V., Rodionov A. V. Application of situational modeling for target distribution of a group of unmanned aerial vehicles. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 179-184. This paper discusses the use of situational modeling for the control process, target distribution of a group of unmanned aerial vehicles (UAV) during the interception of air targets in the attacking mode. General block diagram of the control system of situational type is presented. The method of situational modeling is based on three principles. The first one supposes the possibility of situation classification. The second principle is based on the idea of using special formal means (languages of knowledge presentation) while describing the object under control, the processes of its functioning, and the environment. Such means secure completeness of description for the objects under control and equivalence to the real process. The third principle supposes building the model of object control or the model of entering solutions.
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Alifanov O. M., Nenarokomov A. V., Nenarokomov K. A., Titov D. M. Parametric identification of nonlinear mathematical models of longitudinal waves propagation in materials. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 185-195. The purpose of this research was to develop a computational-experimental technique for remote (non- contact) diagnostics of structural defects in elastic materials. The performance of equipment is based on nonlinear interaction of acoustic beam of finite amplitude and analyzed material. Elastic properties of flaws differ from ones of base medium. Gradient of elastics properties on the border of flaws results in the appearance of non-classic nonlinearity in the domain. Such nonlinearity significantly exceeds the physical nonlinearity of a medium under diagnostics. Determination of spatial distribution of structural acoustic nonlinearity in the specimen allows to spot the defects.
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Alifanov O. M., Nenarokomov A. V., Nenarokomov K. A., Terent'eva A. V., Titov D. M. Finite-difference method for solution to general boundary problem of hyperbolic-type equation in multi-layer domain. Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 196-206. Basic principles and architecture are considered for the problem-oriented program package for solving non- linear ill-posed inverse problems for hyperbolic equation in one-dimensional non-stationary statement. Computational algorithms will be realized in the package for solution to inverse problems and will be built by using the iterative regularization method. The program package will have a multi-level modular structure. The developed algorithm make possible taking into account all keeping experimental information for estimation of materials properties. The equations for calculations of the wave propagation which provide estimation of material properties were formulated. Some ways are suggested for local elements representation. It allows to include the simulating programs in global program to solve the inverse problems for identifying effective characteristics of elastic materials. In the framework of this approach a general direct model were developed: where L is number of layers in the system. The Finite Difference algorithm has been developed as basic approach for simulation of 1-D wave propagation in composite materials. The special uniform Finite Difference approximation was developed for multi-layer domain with different properties of materials. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ageyeva N. G., Rebiy E. J. Management features of creating processes innovative production in enterprises of aviation-industrial complex . Aerospace MAI Journal, 2013, vol. 20, no 5, pp. 207-216. Changing the innovative production creating processes on aviation enterprises due to innovation model improving. Widespread is the new innovation model, initiators and sources of which are the users of innovative developments — industrial complexes, enterprises. This requires the adequate management tools development, which have sufficient organizational, financial, institutional and spatial flexibility.
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Pravidlo M. N., Tikhonov K. M., Belyaev A. N. Mathematical simulation of two stages onboard feed out catapult launch system operation. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 7-16. There exists a number of difficulties by placing guided missiles (GM) into fuselage of the carrier related to the limited space and tight GM placement. These circumstances may cause increased demands on the GM bailout system which should provide GM bailout process without touching GM body and control surfaces both carrier compartment elements and other missiles. An important feature of GM separation chamber is GM length of flight in a limited space due to the substantial depth of the compartment, which leads to a rather large time of the not stabilized GM flight.
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Dolgov O. S., Dolgova T. V., Lyakishev M. A. A method of assessing effectiveness of multi-purpose aircraft systems and individual units at the early aircraft design stages. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 17-26. Purpose
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Golubev S. I. Use of value function in decision making for selection of unmanned aircraft conceptual design. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 27-35. The article suggests use of utility function theory for assessment and decision making in the process of best conceptual design selection of the aircraft of the military- industrial complex (MIC). The utility function allows combining of manufactures and consumers approaches within the process of new technics development and in the same time solves task of the best alternative selection among considered projects. For manufacture the utility is a mean to assess the degree of the product being attractive to consumers and for potential customer utility is a tool to sel ect best alternative among considered.
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Shydakov V. I. Aerodynamic characteristics of the shrouded rotor with an inlet and a short diffuser at the stationary hover operation mode. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 36-46. The paper is focused on the research of the influence of the diffuser length on the aerodynamic characteristics of the «shrouded rotor» system. «Shrouded rotor» is used as lifting and propulsive system on many types of aircraft. Single-rotor helicopter fenestron with a limited diffuser length, which is built into the tail boom fin, is an individual version of such «shrouded rotor» system. The early works of the author adduce the methods of calculation of aerodynamic characteristics of the shrouded rotor with a diffuser, which is long enough to provide the full expansion of the exit air flow stream. However, the fenestron exit flow cannot fully expand due to the limited length of its diffusor. Thus there is a contraction in the exit flow stream of the fenestron, which affects its aerodynamic characteristics.
In this case the shroud lift effectiveness would be ~ 35% of the total system thrust. It can be increased by installing a diverging diffuser with the expansion angle of no more than 12°.
Calculation results were confirmed by the experiment, which was carried out at TsAGI. The specific values of should be determined based on the flow energy analysis. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kopev R. G. Vortex tube and air cycle machine: description, fields of application. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 47-54. The main objective of this paper is to advance the usage of vortex tubes (VT) and air cycle machines (ACM) on aircraft with the purpose of understanding the main advantages and disadvantages of each unit. For that purpose the paper adduces the history of the development and application of the aforementioned units in various branches of engineering. It analyzes the changes in ACM devices structure starting from the two- wheel bootstrap ACM with ball bearings. The usage of a three-wheel ACM with air bearings, which was produced by NPO Nauka, on Tu-204/214 and Tu-334 airplanes, was an achievement for Russian aviation. However, four-wheel ACM with air bearings already exist abroad. Such ACM are operated on Boeing 777, 767-400, Airbus A380 and Embraer E-170/190. At the moment the question of usage of four-wheel ACM, which was jointly developed by NPO Nauka and Hamilton Sundstrand, on the newly developed MC-21 Russian airplane is being considered. Comparison of three- and four-wheel ACM showed that the four-wheel ACM is 91% more efficient in the ground mode and 5% more efficient in the cruise flight mode. Besides ACM it is also possible to use other devices (vortex tubes) for cooling. VTs are not widely used in aviation, although there are many patents concerning this topic. VTs are essentially used for cooling the electronic equipment in the industrial production facilities. The paper adduces the results of VT application by the RWE Energy German Company for natural gas dehydration. The analysis of papers and books shows the main advantages and disadvantages of ACM and VT. ACM units are complex and very expensive, but have a high coefficient of performance. On the contrary, VTs are very simple, cheap, have low weight and low efficiency. However, VTs have still found their own field of application. The paper adduces the data for both Russian and foreign VT manufacturers. This data includes the table of change of air temperature of the VTs, which are manufactured by EXAIR Company, depending on the percentage of the cold fraction. Azarovs VTs prevail in the Russian industrial production. Basic data on these VTs is shown in the paper. The consideration of two types of units — VTs and ACMs will help to understand the fields of their application, as well as their advantages and disadvantages, more fully. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nesterov V. A., Mironova M. M. Aircraft both velocity and flight altitude adaptive control algorithm. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 55-62. It is considered aircraft both velocity and flight altitude adaptive control algorithm, based on the reverse flight dynamics approach.
Mathematical simulation has been performed in order to analyze developed algorithm performances. Simulation results are given, which demonstrate algorithm operability and efficiency in presence of the uncontrollable factors. Developed integrated control algorithm provides increasing operation speed of both velocity and flight altitude control loops as well as reducing fuel consumptions due to flight altitude optimization. So, suggested approach can be used for prospective thrust control algorithmc development. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhigastova O. K., Pochukayev V. N. Decomposition of the flight plan to target fragments as an effective method for improving of automatic spacecrafts work planning procedure. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 63-71. The article is dedicated to improving of automatic spacecraft flight planning procedure. The proposed method is based on decomposition of the flight plan into a set of target fragments. The target fragment concept is connected to the feature of the functioning and executing of the spacecraft targets tasks. Automatic flight control of the spacecraft can be considered as control of its space-time condition [1], which ensures the achievement of the spacecraft targets tasks. Design/methodology/approach
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Zolotov A. A., Nurullaev E. D. The monitoring methods for technical systems reliability. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 72-80. The reliability ensuring problems of space-rocket products are considered. The space-rocket products reliability at various life cycle stages is analyzed with the help of change forecasting models. The analytical model of space-rocket products reliability indicators estimation is presented. Depending on tests the results of analytical model allow to receive different reliability characters corresponded to the stages of tests and operations. It follows that with increasing of workout cycles refusals number the law of «growing old type» corresponded to operational stage is forming and with decreasing of refusals number on workout time the model of «burning out refusals» corresponded to tests stage is forming. The maintenance parameters of numerical evaluating method are presented based on tests results. Against the traditional model the presented method reflects the real units functioning processes more adequately, for example, the real maintenance character of refused elements replacement is considered; the law of «growing old type» units reliability allocating is used; stationary and non-stationary operating units mode are considered.
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Pugachev A. O., Ravikovich Y. A. Application of brush seal technology in modern turbomachines. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 81-89. The paper presents an analysis of brush seal technology applications in modern turbomachinery. The brush seal designs, their advantages and disadvantages are described and discussed. Brush seals show a superior leakage performance comparing with conventional labyrinth seals. However, due to the compliant nature of bristles the behavior of the bristle pack is very complex. The performance characteristics of brush seals can largely depend on the geometric parameters, mechanical and aerodynamic state of the sealing unit. Proper design and application of the brush seals allow constraining the bristle wear. The impact of brush seals on the turbomachine rotordynamics is one of the key considerations with very limited data available. A small number of lab-scale experimental studies have demonstrated overall improved dynamic coefficients in comparison with the labyrinth seals. However, the field experience has shown both positive as well as negative influence of brush seals on rotordynamics. Using aramid fiber with smaller diameter than the metallic wire can further reduce leakage through the brush seal. The main problems with aramid fiber brush seals are limited temperature operating range and structural stiffness. In spite of some problems, the brush seal technology has been successfully applied abroad in air-breathing engines, and also in the industrial gas and steam turbines. Detailed studies are presently carried out for better understanding various phenomena occurring in brush seals and for solving experiencing problems. Several attempts to apply brush seal technology have been taken also in Russia with only limited positive outcome. Therefore, more investigations are needed for faster deployment of this novel sealing technology. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yanovsky L. S., Raznoschikov V. V., Sharov M. S., Kolomentsev P. A., Popova A. B. Effect of solid fueled ramjet forcing on flight vehicle performances. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 90-98. To the supersonic flight vehicle of an atmospheric zone of operation, with impellent installation using as a mid-flight stage the solid fuel ramjet (SFRJ), after the termination of work of a starting stage can be demanded additional acceleration till the speed necessary for steady work of ramjet. Realization of it is possible by means of engine forcing at placing of an additional solid fuel grain in the channel on the case of a starting stage. Characteristics of engine and, accordingly, flight vehicle characteristics change at a variation of forcing degree which is defined by geometrical parameters of an additional solid fuel grain. In this study calculation of characteristics of engine has been performed by an iterative method on the one-dimensional model, based on the conservation equations. As the initial data for modeling the international standard atmosphere, throttle performance of air inlet, characteristics of solid fuel and geometrical parameters of the engine were used. In addition given model has been corrected by results of experiments on connected pipe facility which have been performed at various forcing degrees of solid fuel ramjet. The rate of gasification for main solid fuel grain and combustion efficiency in the mixing chamber have been corrected. Correction was performed by inclusion of corresponding coefficients to model. As a result of calculation dependences of the flow rate of air through the engine, gasification products flow rate dependences, thrust coefficient dependences and dependences of the ratio of thrust coefficient to drag coefficient have been obtained as a functions of flight Mach number for different operating conditions. Calculation of flight vehicle characteristics has been performed using flight vehicle mass center movement mathematical model which includes two dynamic equations, two kinematical equations and the equation of weight change. Effects of different forcing degrees of a solid fueled ramjet on speed and flight range of supersonic flight vehicle have been assessed by results of this calculation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobey V. V., Evstratov S. V. The technology of production the airplanes intake air system by the winding method. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 99-109. The paper is focused on development of manufacturing process for a supersonic aircraft air intake system using a new winding technique. The air intake system is a complex spatial structure with a S-shaped centerline and irregular-shaped cross-sections varying from a parallelogram with rounded corners at the entry of the system to a circle (920 mm at the outlet. Currently there is no practice of manufacturing such systems using the winding technique anywhere in the world. Some parts of the air intake system structure may well be produced using the existing methods but according to the task in hand a single and uniform method should be developed to produce the whole structure. To accomplish this task the following problems have to be considered: Crosswise winding developed byRussian specialists isproposed asmanufacturing technique for the structure. tasks include: The paper shows the key calculation results for the most thin-walled envelope ofthe air intake system manufactured from carbon fiber composite. Calculations have been made for the walls with various thicknesses. These calculations prove the feasibility ofthe air intake system design produced using the proposed method. The paper also gives details about structural design and production technology for the structural components ofthe multi-unit mandrel, properties ofsome materials used, the assembly procedure and removal ofthe mandrel from the wound structure | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chubov P. N., Rumyantsev А. V., Krochak L. Z. Thermal design of the stationary plasma thruster thermothrottle. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 110-117. Efficiency and reliability of products performance much depend on conditions of internal and external heat exchange of products elements. These conditions define the thermal environment and impose certain requirements on the temperature control systems. The combination of computational analysis technique with experimental measurements, both ground-base and actual, appears to be the most effective way for solving the temperature control problem. In this connection, the primary task of the research was to evaluate the temperature field and metering characteristics of Stationary Plasma Thrusters (SPT) flow controllers. The mathematical model was developed for the evaluation of the thermal profile of thermothrottle (SolidWorks application software-based flow controller of Electric Propulsion System). And the heat calculation results for thermothrottle were also presented. The calculations for the thermothrottle were made for different current values in a range from 1А to 4А with 1А step. The results were compared with the experimental data received earlier and the calculations obtained through the SPRUT software. Besides that, gas-dynamic calculations were carried out with the help of SolidWorks application. The data were also received for different current values in a range from 1А to 4А with 1А step. Computed data were compared with the results of the flow controller experimental tests. The application of SolidWorks software package allows quite accurately to define the flow controllers thermal environment with different current values during operation, on one hand, and metering characteristics with different current values in thermothrottle, on the other. Moreover, it helps to make prognosis on thermal environment of thermothrottle in case of any changes in configuration of the capillary or its operation mode without undertaking numerous testing, allowing to reduce the overall expenses during products manufacturing phase. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mirzoyan A. S., Khmarov I. М., Kondrashov N. G., Shakhov S. V. Method of ground-objects isolation against the background of underlying surface in on-board 3d laser channel. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 118-129. Application of aircraft laser optic-electronic channel for 3D ground-objects image acquisition is the perspective direction of automatic recognition system development. For secure ground-objects recognition their qualitative isolation against the background of underlying surface is required. Ground-objects isolation is suggested to realize on the basis of 2D underlying surface approximation of in laser channel coordinate system.
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Samoilenko M. V. Tomography method of complex spectrum restoration by the power measurements at the outputs of the comb of resonators. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 130-135. A new tomography method of spectrum analysis is suggested in the article, which connects an analog filtration with the original digital processing. A number of advantages of the method are a result of such connection. Compared with the methods based on a digital processing of periodogram or an autocorrelation function of the analyzed signals which are suitable only for low-friquency signals, the suggested method is free from such restriction about frequency range and can be applied both for low-frequensy and for high-frequency signals. And thus the tomography method is capable to provide high precision of spectrum analysis comparable with the digital methods precision and far surpassing the possibilities of the analysis spesifically by means of a comb of resonators. The tomography method allows to reach new qualitative result ( to restore complex spectrum by means of power measurements of the signals at the outputs of the comb of resonators. Complex spectrum allows to restore a signal, that is why its definition is quite an actual problem. Tomography method allows to solve this problem with the help of simple power measurements. In the article, there is given the mathematical description of the method as well as the scheme of its realization which was also elaborated by the author. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerko S. A. Performance evaluation of filtering algorithms for new orientation system based on single-band gnss equipment. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 136-145. This paper discusses the perspective for application of the filtering methods for new spatial orientation determining of the high-tech objects by means of global navigation satellite systems (GNSS). The peculiarity of this algorithm is that it uses information about the remaining unchanged lengths of the main and closing base-vector measurers in addition to the second difference of pseudorange and pseudophase measurements. Filter results ship heading angle show that the new algorithm for integer ambiguity resolution, combined with the Kalman filter algorithm, enables high probability of right integer ambiguity resolution using relatively low-cost single-system and single-band equipment meter and a relatively small number of visible satellites. It was found that increased tolerance to the fluctuations of core measurer lengths leads to an increasing in the probability of occurrence of the true as maximum credibility, or in other words, it increases the probability of correct integer ambiguity resolution. The results can be used as algorithmic and practical basis for the implementation of filtering tools onboard moving objects for solving task of orientation by means of GNSS provided computationally efficient software is developed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubenskii A. A., Kovalev L. K., Modestov K. A. The calculation technique of the magnetic circuit of superconducting synchronous electric machines for perspective aircraft. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 146-158. This paper is devoted to development of a generator with high-temperature superconducting (HTS) field windings, claw-like poles and permanent magnets on the rotor for on-board network power supply of fully electrified aircraft.
Application of permanent magnets on the rotor together with field windings is necessary for power supply provision in case of cryogenic system failure. The magnetic flux of permanent magnets creates the basic value of electromotive force (EMF), and the superconducting excitation windings are necessary for voltage regulation during operation of the generator. Magnetomotive force (MMF) of HTS field winding is several times more than MMF of a copper field winding. The saturation of some parts of the generator magnetic circuits is possible. Therefore, decrease of magnetic potential must be taken into consideration not only in the main air gap, but in ferromagnetic elements also. The method of magnetic circuit theory and iteration technique were used for estimated calculation of the magnetic circuit. The distribution of a magnetic flux density is considered to be homogeneous in each element of a magnetic circuit. This allows to investigate the generator with the method of magnetic circuit theory. On the base of the magnetic flux distribution an equivalent scheme of magnetic circuit was developed. The equivalent current was calculated by the method of electric circuit theory (method of nodal potentials). The equivalent scheme of a magnetic circuit becomes simpler if values of some fluxes are small in comparison with the main magnetic flux. In this case their values are considered as equal to zero, and calculation of magnetic circuit can be carried out on the simplified equivalent circuit. In order to take into account the magnetic saturation effect the calculation was carried out by s method of iterations when values of magnetic permeability of each elements of a circuit are specified in accordance with a magnetization curve on each step of iteration. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gordeyev A. V., Sidorov A. S., Khoroshko A. Y. The method of power losses reduction in switching shunt regulator. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 159-167. The paper examines a new method of power loss reduction in switching shunt regulator. The main idea of the method is to recuperate the excess energy accumulated in cable line due to solar array capacitance discharge into load. Recuperation is implemented with the help of shunt switch additional control law that is called in the paper as a nested relay control. The nested relay control assumes that at the moment when solar array capacitance discharge current exceeds the predetermined limit the shunt switch turns off and the current flows through the load. To implement this control law a schematic was proposed. The schematic consists of a current sensor, a comparator and OR logic element. An experimental was developed. The model features the output power of 700 W and operating frequency of 10 kHz. As a power supply for the shunt regulator a solar array simulator with analogous dynamic performance was developed. Experimental studies of the shunt regulator model with the new control law showed that power loss in cable lines that connect the solar array with shunt regulator was reduced at least by 25% while power loss increase in semiconductor switches was negligible. Design procedure of the new schematic solution is proposed. The design procedure allows calculating the comparator thresholds when cable line inductance and solar array capacitance are known. The proposed schematic and the control law are assumed to be utilized in spacecraft power supply systems. The advantage of the proposed schematic as opposed to known solutions is that the schematic doesnt redistribute energy accumulated in the solar array capacitance among shunt regulator components and the components of specially developed devices but transfers the excess energy to the load. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nesterov V. A. Finite element analysis of shells considering transverse shear . Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 168-178. Composite materials are intensively used in different structures, for instance for aerospace technic due to its high strength-to-weight and stiffness-to-weight ratios. At the same time composites have some specificity which should be considered, the main one is the low transverse shear stiffness. Taking into account transverse shear strains increases the order of governing equations.
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Kudimov N. F., Panasenko A. V., Safronov A. V., Tretiyakova O. N. Numerical simulation of multiple turbulent supersonic underexpanded jet. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 179-185. In this paper, the quadruple supersonic turbulent underexpanded jets are numerically simulated. The main goal of the presented research is to provide the numerical simulation for multiple turbulent supersonic underexpanded jets considering their interaction. A mesh of the numerical model consists of 10 million cells providing good modeling of expansion waves, shock wave such as the incident shock, reflected shock, and slip stream line in the supersonic jets. Numerical simulation is based on the three-dimensional Reynolds equations with SST k-? turbulence model being the two- equation eddy-viscosity model. The use of a formulation for the inner parts of the boundary layer makes the model directly usable all the way down to the wall through the viscous sub-layer, hence the SST model can be used as a Low-Re turbulence model without any extra damping functions. The SST formulation also switches to a behaviour in the free- stream and thereby avoids the common problem that the model is too sensitive to the inlet free-stream turbulence properties. Three dimensional compressible Reynolds equations are solved using finite volume method with the Godunov-type TVD scheme of the second order in space discretization. In calculation varied pressure ratio n = pc/pb, where pc is the static pressure at the nozzle exit and pb is the ambient pressure. It is shown that the incident shock has regular reflection from an axis of a block jet for pressure ratio n=1.45. For n=1.2 the incident shock cant pass through the slip stream line. In process of further increase pressure ratio n incident shock has irregular reflection and a strong shock forms around the centerline (Mach disc). Downstream of the Mach disc the flow becomes subsonic and the pressure and density is raised up. Conclusion The complex flow structure of multiple supersonic turbulent jet is simulated numerically; The formation and structure of multiple supersonicturbulent jets is investigated; Influence of the pressure ratio of multiple turbulent supersonic jets is shown (both regular and irregular reflection); The applied method can be recommended for the development of space-rocket technic.
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Girin A. M., Povoljaev S. T. Study on vibration of cylindrical shells of variable stiffness. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 186-190. Purpose A set of shell structures are used in modern motor power plants of aircraft. These shells are often axisymmetric and have variable physical, mechanical (e.g. bending stiffness and tension-compression one), and geometrical (e.g., thickness and diameter) properties and often include some elements of fragile materials (such as ceramics, glass, tungsten etc.). The effect of high frequency vibration loads must be considered at the stage of the preliminary design of the mentioned shell structures. Design / Methodology / Approach The proposed method is based on the solution of the boundary integral equations and allows the quick and accurate determination of the resonance conditions. This method gives the working capacity boundaries of real complex shell structures on the basis of the vibration resistance criteria, or to change the properties of designed structures to ensure their working capacity in the given operating frequencies range. An experimental plant is designed to confirm the theoretical results and can be used for the vibration tests of full-scale objects as well as their models. A method of analysis of the free oscillations of cylindrical shells with variable properties, for instance, material density, elasticity modulus, and the wall thickness, is developed on the basis of the integral equations of the moment shell theory. The hypotheses of the absence of the tension in the circumferential direction and of the shear in the shell midsurface, as well as the Kirchhoff-Love hypothesis have also been used. Findings The eigenfrequencies for the cylindrical shells with variable thickness along the generatrix are computed. An experimental plant permitting the automatic determination of the resonance frequencies, as well as circumferential and longitudinal oscillation modes is constructed. The theoretical values of the eigenfrequencies are in the good agreement with the experimental ones. Originality / Value The details and units of the power plants of modern aircrafts are subjected to the intense high-frequency vibration loads, so the information about the behavior of structural elements is very important at the preliminary design stage. The proposed method allows one to determine the optimum properties of shell structures and avoid any resonance modes in the real operation conditions. The designed experimental plant can be used to test the full-scale parts and structural elements of aircrafts under dynamic loads. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krasilnikov P. S., Amelin R. N. On the destabilization of some equilibriums of nonconservative system with three degrees of freedom. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 191-197. This paper focuses on Zieglers effect. This effect is the destabilization of stable equilibrium of system ’$under the action of small friction forces. This effect exists if and only if the system is subject to the potential forces, the following forces and the linear forces of a viscous friction. The following force is a jet force of jet engine. The following force is a positional force that do not have a potential energy. Therefore the effect of destabilization can prove oneself when the jet engine of launch vehicles works. The destabilization of stable equilibrium of some system of rods, which model a complex engineering structure is considered. It is suppose that the rod system is subject to the potential forces, the following forces and the linear forces of a viscous friction. First approximation equations are obtained. It is shown that these equations fall into two subsystems with one and two degree of freedoms accordingly. The conditions of asymptotic stability and instability as a first approximation, the conditions of the existence of Zieglers effect are obtained. It is shown that Zieglers zone is a narrow band close to a boundary of stability area. By means of theorems of partial asymptotic stability and instability, necessary and sufficient conditions of asymptotic stability in complete equations are obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Doan T. N., Hieu L. T. The update theory calculation of the strain-stress state of cylindrical chells with variable thickness. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 198-211. The closed cylindrical shell with variable thickness being the function of longitudinal coordinate is considered as a three-dimensional body. The governing equations of three-dimensional elasticity theory are used. The components of strain- and stress state for the shell are represented as the polynomial functions of the thickness coordinate. These functions are two orders higher with respect to these of the Kirchhoff-Love theory. The virtual work principle is applied to obtainthe two-dimensional equations and its natural boundaryconditions.
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Agamirov L. V., Agamirov V. L., Vestyak V. A. Umerical methods and algorithms of calculation of exact distributions of non-parametrical criteria statistical hypotheses. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 212-218. One of the important tasks of statistical analysis is calculation of percentage points of hypotheses testing criteria. The peculiarity of this task for nonparametric ranking criteria is the need for accurate calculation of percentage points of distribution as a result of low accuracy of crude approximations at a small scope of survey, while nonparametric criteria are particularly effective when working with a small sampling. Inappropriateness of using for this purpose statistically common normal or other approximations [4-6] is accounted for by the fact that well-known ranking criteria (sign test, Wilcoxon sign rank test, Wilcoxon two-sample test, Kruskal-Wallis test, etc.) refer to the area of nonparametric statistics, while for whatever reasons no assumptions are made about the kind of hypothetical function of distribution of the random variable under study. With technical problems, especially when analyzing the results of mechanical tests, such a situation occurs due to a small amount of tests, considerable scattering of properties due to structural heterogeneity of constructional materials and a large variability of external factors during the tests. Thus distribution approximations of nonparametric criteria statistics, while for the reasons given above these criteria are particularly effective with a small sampling.
Another way of accurate calculation of Wilcoxon distribution statistic is the use of the following recurrent formula [2]: with the following initial conditions: In this paper we suggest several algorithms of calculation of exact distribution of ranking criteria statistics.
Conclusions
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Krotov P. R., Dvornikov I. V., Shmelev S. A. Technique of an estimation of efficiency of the researches actuated in the project of comprehensive plan research works within the limits of developed «the national plan for development of a science and techniques in aircraft manufacturing for the period till 2025 and the subsequent perspective». Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 227-234. The method is designed to assess the priority of the stated researches included in the project of Comprehensive Scientific Research plan as part of working out National plan of science and techniques developments in the aircraft industry for the period till 2025 and the subsequent perspective (further the National plan). Processing methods of the experts opinion engaged in expediency consideration of stated researches in the National plan about the importance of separate types and research directions in the field of air science and techniques development and also methods of forming «utility function» activities at the multicriteria approach of their efficiency assessment are put in the technique basis of the approach (as one of the ways of forming the compromise solutions about the significance of the stated researches). The given technique allows to range proposals on a significance level taking into account the data of the request characterising efficiency, cost and a realizability of offered research, considering the established limits of financing of the National plan. Applied methods of research: decision-making techniques for multicriteria problems, methods of utility theory and systems analysis methods. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volodin S. V. The methodology of the strategic project-management in the aerospace branch. Aerospace MAI Journal, 2013, vol. 20, no 4, pp. 219-226. The aim of this work is to develop a model of strategic project management in the face of uncertainty and taking into account the specifics of the aerospace industry. It was also intended to identify the impact on the efficiency of the projects the intensity of competition and the time factor. The methodology of this paper is based on a common approach to the management of development and change (mainly at the organizational level). Additionally Approaches related to the STEP-and SWOT-analysis, competitive analysis and portfolio current and developing project management strategies. To estimate the discount rate adopted cumulative construction method using probability theory to calculate the random variation of the variable part of the discount rate. As a result of the generated model of the strategic management of the project, which builds on the definition of objectives and the expectations of stakeholders. On the model examples with realistic initial data shows economic costs associated with an increase in the number of competitors in the industry, the benefits of the integration of its members, the impact position of the leader and the follower. In the Stochastic see the effects on investment. Results of the development model of strategic management of projects under uncertainty can be of practical use in the aerospace industry with goal-setting, the feasibility study and development of network planning perspective. This paper proposes new approaches to assessing the impact on the efficiency and effectiveness of projects deviations from nominal conditions for their implementation. It should be noted cyclic model of strategic project management, which takes into account the presence of feedback caused by the need to adjust for the purposes of identifying defects strategy mismatch of needs and available resources of the project. Also are original approaches to the parametric study of the structure of markets and the use of a random number generator to assess possible changes in the efficiency of investment in aerospace design. The results can be useful researchers, graduate students and applicants of the Moscow Aviation Institute, and other institutions that are working in the field of aerospace engineering. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pravidlo M. N., Belyaev A. N., Kosarev A. V. Single stage inboard catapult launching system simulation. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 7-18. The aircraft-carriers (AC) of the fifth generation are characterized by intrafuselage accommodation of aircraft guided missiles (AGM), which is essential for the improved operational and physical characteristics of the aircraft, by maintaining its aerodynamic efficiency and reducing the radio cross section. Moreover, there is the task of providing safety ejecting AGM with the exception of collision AUR and the providing of the AGM spatial stability due to their specific intrafuselage placement. Specific features of ejecting from AC compartment are intrafuselage limited space, complex aerodynamic flow of AGM arising after the opening of the valves and large extent unregulated flight AGM in a confined space deep (with flaps) AC fuselage due to undisclosed control surfaces (CS). This article analyzes the requirements for provided by intrafuselage ejection device (IFED) parameters of linear and angular motion detachable AGM. These requirements are generated using a model of aerodynamic interference AGM and AC, built on the basis of puffs model AGM in the presence of AC model. IFED discussed three types: Short-stroke (ystroke= 0.15 m), average-stroke (ystroke = 0.25 m) and the long-stroke (ystroke = 0.5 m). Developed a model of the kinematics of long-stroke IFED with double acting pneumatic actuator (direct and reverse motion), and the recommendations generated by the geometric characteristics of the kinematic scheme of long-stroke IFED with the dynamic analysis of structures. Model of the dynamics of elastic IFED is developed taking into account the deformation of its rods and using the Lagrange equations of the 2nd kind. As an actuator in the IFED examines the use four-cavity double acting pneumatic and developing pull force is determined by taking into account the adiabatic process. According to the results of numerical simulations on a computer by the Runge-Kutta parameters offices AGM on various modes of the airplane, it was found that during ejection, the vertical velocity of the center of mass AGM (Vy) is monotonically increasing, overload (ny) is practically constant, and the angular velocity (ωz) although it varies, but with a constant sign. Estimation of parameters of ejecting AGM from AC formed by the long-stroke IFED drawn on the basis of motion simulation through AGM (comprising the steps of: moving on AGM IFED; flight AGM since its separation from the IFED to the moment of disclosure control surfaces; flight AGM after the disclosure of CS, stabilization of AGM after the disclosure of CS), showed that the trajectory of the AGM are at a safe distance from the AC in a wide range of conditions of its flight. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brusov V. S., Petruchik V. P., Kuznetsov A. V. Investigation of wing airfoils for low-speed high-altitude unmanned aerial vehicles. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 19-31. High-altitude low-speed unmanned aerial vehicles (UAVs) are designed to fly for many days in the stratosphere (within the range of altitudes from 25 to 30 km). Such UAVs can be considered as an effective alternative to artificial Earth satellites concerning carrying out such missions as Earth surface observation, meteorological service, telecommunications etc. The effectiveness of stratospheric UAVs is heavily influenced by their aerodynamic characteristics, which depend significantly on the properties of the used wing airfoils. Small values of the Reynolds number (Re = 3?104...5?105), which are typical for the operation of stratospheric UAVs, result from the conditions of low-speed high-altitude flight regimes. Such values of Reynolds number cause significant degradation of aerodynamic characteristics of wing airfoils. Thereby the problem of reasonable choice of the UAV wing airfoil becomes a very important part of the UAV design process. It is impossible to fulfill the numerous requirements for the stratospheric UAV, which often contradict each other, without successfully solving this airfoil choice problem. A comparative analysis of characteristics of possible versions of UAV wing airfoil was carried out to support the choice process. The following airfoil versions were considered: FX 63-137, WE 3.55-9.3, S1223 and Liebeсk LA2573А. The analysis, which was based on the previously published data, specified the FX 63-137 and WE 3.55-9.3 airfoils as the most suitable for further research. The appropriate experiments were conducted in the T-1 wind tunnel, which is installed at the MAI. The experiments were aimed at obtaining the following observed relationships for the airfoils: dependencies of the lift, drag and pitching moment coefficients on the values of the angle of attack and Reynolds number. According to the results of the wind tunnel tests, the maximum values of the lift coefficient were recorded for the FX 63-137 airfoil. These values lie within the range from 1.75 to 1.8. The maximum values of lift-to-drag ratio were recorded for the WE 3.5-9.3 airfoil. These values lie within the range from 55 to 60. Besides these investigations some wind tunnel tests were carried out to obtain aerodynamic characteristics of the UAV wing, which is equipped with the FX 63-137 airfoil and streamlined by the additional blowing flow from a rotating propeller. The test results demonstrate that the values of the wing lift coefficient increase by average 10-15% due to the propeller blowing whereas the values of the pitching moment coefficient decrease by approximately 25%. At the same time the drag coefficient values of the UAV wing increase by 10%-15% under the considered conditions. The experimental results, which are presented in the paper, can be used to support the process of aerodynamic design of the low-speed high-altitude unmanned aerial vehicles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krivtsov V. S., Pavlenko V. N., Voronko V. V., Vorobjev Y. A., Shostak I. V. Complex approach to robotic automation of assembly processes in aircraft manufacturing based on fuzzy logic. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 32-39. Subject of research Manufacturing of light jet airplanes for general aviation fleet of both Ukraine and foreign countries is connected with certain problems. These problems are determined by the necessity to manufacture rather large series of airplanes with a huge number of modifications within each series. Further complications are due to the fact that this manufacturing should be of high quality and should be carried out during a limited period of time. Organization of assembly effort is a weak point in manufacturing of light jet airplanes. This is in particular true for the following operations: intercoordinating details and component parts during their installation, fixturing the component parts in a specified position, joining structure elements. Replacement of assembly workers with robotic tools leads to a problem of development of special smart robots, which should emulate the behavior of an assembly worker to a certain degree.The paper aims at describing the complex approach to application of fuzzy logic apparatus for the synthesis of the appropriate adequate models and methods of control of automated robotic line for aircraft structure components assembly, which uses smart robots. Methodology of research The authors used the method of assembly, which is based on virtual datum surfaces, as a methodological basis for organization of manufacturing processes within the automated robotic line for the assembly of light jet airplanes. The work describes a complex approach, which consists of two stages. The first stage consists in the synthesis of a typical fuzzy model, which can be used for the decision-making by smart manipulation robots during estimation of the surfaces of the matched component parts in the process of assembly. The second stage consists in developing a fuzzy model for coordination of actions of a group of smart manipulation robots, which function within an automated robotic section of the aircraft structure component assembly line. Results of research The paper presents a two-stage approach to robotic automation of a section of the airplane structure components assembly line that suggests synthesis of world models for both separate smart robots and a group of robots, which function within an assembly line section, on the basis of fuzzy logic. The work describes a typical fuzzy model of a smart robot, which estimates component parts surfaces on the basis of virtual datum. It also adduces a rough outline of the fuzzy model of coordination of a group of three manipulation robots, which function within a section of airplane structure components assembly line. The functions of these robots include component matching according to the method of virtual datum surfaces. Conclusions Intensification of production of light jet airplanes implies robotic automation of the line assembly of aircraft structure components. Such automation can be carried out, in particular, on the basis of the method of virtual datum surfaces. It is rational to use a two-stage approach to implement robotic automation of the assembly effort in aircraft manufacturing. The first stage consists in gradual development of a typical world model for an individual smart robot. The second stage consists in developing a behavior model for a group of smart robots, which function within an assembly line section. At that fuzzy logic proves to be an efficient mathematical tool for synthesis and implementation of world models of smart manipulation robots during aircraft structure component assembly. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I., Biryukovа M. V. Algorithm for forecasting of radiating influence on microsatellite equipments. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 40-49. For forecasting of reliable work of space vehicles (SV) devices the knowledge of radiating conditions along the flight line of Earth satellite is necessary. The exact calculation of radiation stored doses in electro-radio devices (semi-conductor microcircuit chips, diodes, triodes and other products) as a part of SV instrumental technics in condition of long-term active existence on orbit is impossible. The forecast of solar proton events for a long term and corresponding modeling of magnetic sphere indignations from various influences have not so high probability. In this case the maximum and, sometimes, the overevaluated estimations of stored doses are important for comparison of summarized doses stored by satellite equipments with radiating firmness of its element base for a long time.
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Darnopykh V. V., Malyshev V. V. Formalization of optimization problem for satellite observation and communication systems constellations on the basis of operative planning of their target functioning. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 50-60. The control of target operations is one of the important phases of modern satellite observation and communication systems functioning. Their constellations can include a score of spacecrafts located in different altitudes of planes as well as at several orbital segments, and they are multi-satellite. Efficiency of systems target functioning, for example, film-making information, productivity of SC on-board equipment, operationability of data transmission or another indicator (criterion) should meet the requirements of customers. Optimization of systems constellations is necessary for increasing their efficiency mentioned above. Generally, such optimization is a fundamental problem of modern control theory which is characterized by polynomial complexity. Universal approach for its solving has not been offered till present time. That is why this problem is very relevant now especially for perspective multi-satellite observation and communication constellations.
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Evstratov D. I., Lalabekov V. I., Samsonovich S. L. Comparative calculation of element mass index of energy tract gas-hydraulic drive control aircraft. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 61-66. Minimizing the mass of aircraft systems such as the drive controls is an topical problem, which increases the effectiveness of an unmanned aerial vehicle as a whole. The article describes the solution of the alternative gas generator selection problem with a minimum mass by the example of two types of gas-hydraulic drives with equal capacity, which have in its structure solid-fuel gasifier with axial piston motor-pump and turbo pump assembly as a source of energy. The feature of the joint action of the solid gas generator and converter of the gas energy to the energy of the power fluid is the constant pressure to the axial piston motor-pump unit and the variable pressure for the turbo-pump unit output power converters, depending on the consumption rate of the power fluid in the steering apparatus and the operating temperature of drives in the aircraft. Taking into account these features of the work the expressions that allow to calculate the mass properties of the solid gas generator to ensure equal output power for the observe unit within a specified time work were described by the use of the conservation of mass flow equation of in the gas path of energy sources. Graphical-analytical way shown, that the mass of solid propellant gas generator for axial-piston unit ~ 35% lower the solid mass of the gas generator for the turbo pump assembly assuming equal weight steering engines and power converters. The problem of choosing an energy source gas-hydraulic steering actuator controls the aircraft was solved through a comparative analysis of solid-fuel gas generators mass index for the two power converters: an axial piston motor and turbo-pump units with equal power output. The obtained results and the proposed approach for the comparative analysis of mass characteristics and selecting drive power source may be used to select other types of energy sources: air pressure accumulators, of sealed batteries, liquid and gas generators, etc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pugachev A. O., Ravikovich Y. A. Application of brush seal technology in modern turbomachines. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 67-75. The paper presents an analysis of brush seal technology applications in modern turbomachinery. The brush seal designs, their advantages and disadvantages are described and discussed. Brush seals show a superior leakage performance comparing with conventional labyrinth seals. However, due to the presence of moving elastic elements the brush seal behavior is very complex. The performance characteristics of brush seals can largely depend on the geometric parameters, mechanical and aerodynamic state of the sealing unit. Proper design and application of the brush seals allow to limit the wear of fibers. The impact of brush seals on the rotor dynamics of the turbomachine is one of the key considerations with very limited data available. A small number of lab-scale experimental studies have demonstrated overall improved rotor dynamics coefficients in comparison with the labyrinth seals. However, the field experience has shown both positive as well as negative influence of brush seals on rotor dynamics. Using aramid fiber with smaller diameter than the metallic wire can further reduce leakage through the brush seal. The main problems with aramid fiber brush seals are limited temperature operating range and structural stiffness. In spite of some problems, the brush seal technology has been successfully applied abroad in air-breathing engines, and also in the industrial gas and steam turbines. Detailed studies are presently carried out for better understanding variousphenomena occurring in brush seals and for solving experiencing problems. Several attempts to apply brush seal technology have been taken also in Russia with only limited positive outcome. Therefore, more investigations are needed for faster deployment of this novel sealing technology. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolaenko V. S., Filippov G. S., Jashenko B. Y. Calculation of energy spatial distribution for complicated emitter. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 76-85. The new technique is developed for carrying out calculations of an indicatrix of an infrared radiation of the aircraft propulsion system (PS). It is based on a Monte-Carlo method. It is a numerical method of solution of mathematical tasks by means of model operation of random values. Creation of Mathematical Model The engine represents the composite geometrical figure therefore in calculation a number of simplifications is accepted:
Each geometrical surface is divided breaks into a number of the elementary surfaces with area dSm, n . For each elementary surface temperature dTm, n and blackness degree ⍺m, n are set. The beam direction for a microcell of the radiating surface is set in a random way. The beam leaves the center of this microcell. It is considered that all radiant energy of a microcell is distributed in the specified random direction. Then beam crossing with all geometrical surfaces in the main frame (the equations of a beam and the equation of surface of revolutions are solved in unison) is considered (fig.). The surface is reflecting at realization of conditions of an identical orientation, crossing in limits (|Zmax| >|Zm,n|> |Zmin|). If the surface is reflecting, in a point of their crossing the new casual direction of a reflected beam is defined. If the closest surface is a summation hemisphere, the beam leaves the nozzle, and the coordinates of it intersection with the conditional summation hemisphere are defined. Energy of a reflected beam decreases depending on a surface reflectivity. Coordinates of a cross point of a beam with a summation hemisphere and energy of a beam are recording. The summation hemisphere is divided into sections. Energies of the beams falling on each section are summering. Thus, the radiation indicatrix is calculated. The relative positioning of PS and frame: 1 crossing of a beam with a surface; 2 cross points of the line of a beam with surfaces; 3 point with coordinates of Xc m,n,Ycm,n, Zcm,n ; 4 point with coordinates of X02m,n, Y02m,n, Z02m,n (in a local frame) or Xcnm,n, Ycnm,n, Zcnm,n (in the main frame); 5 vector ⍴m n of the casual direction of a beam; 6 surfaces of the partial platform of dSm,n; 7 vector of a normal of Dnm,n to a surface of the partial platform of dSm,n | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volchkov G. V., Vystavkin A. G., Maksimenko D. V. The development of a transformable space nuclear power system. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 86-94. The article is devoted to one of the stages of forming of a future space nuclear power system, in particular — the development of a transformable design of such a facility. Considering the need for development transformable system, the factors that lead to it are:
Reducing the influence of ionizing radiation fluxes is achieved by solving an optimization problem to minimize the total weight of the radiation protection system with Pushing system and communications. The second factor is the result of the conversion of heat into electric power in the reactor-converte. Therefore, it is necessary to increase the area of the cooler-radiator. It is proposed to increase reliability of the cooler-radiator by using of high-temperature thermal tube in the structure. The basic complexities of creating a transformable system and the requirements for it are shown. This brief analysis of possible ways for structure transformation leads to the selection of the optimal alternative. The selected convertible system, which is called «rope», is represented, principle of its operation at the space nuclear power system is shown. The option of creating a reliable hydraulic connection for the possibility of transfer of the coolant in the chosen system is offered. The need for calculations for ground layout for the tests, which imposes additional conditions in the mathematical description of the process, is indicated. Represented calculations include:
The conclusions indicate the direction of further works on the creation of the transformable systems for the second generation space nuclear power plants. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shcherbakov M. A., Vorobyov D. A., Maslakov S. A., Ravikovich Y. A. Calculation of heat-transfer coefficient on a turbine blade airfoil in abnormal modes. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 95-103. This article comprises results of studies aimed at defining the area of applicability of criterion dependences for obtaining the distribution of the heat-transfer coefficient on a rotor blade airfoil of small-size uncooled turbine. Design and abnormal turbine operating modes have been studied. The value of heat-transfer coefficient on a specific section of the airfoil is calculated using known criterion dependences or by means of simulating the heat flux into the blade using ANSYS CFX. The rotor blade was divided by mid-radius into two major sections in the network of calculating the heat-transfer coefficient using criterion dependences. The parameters of gas flow corresponding to average values of the parameters at these sections have been used for further calculations. Criterion dependences corresponding to the parameters of flow at the specific section were used during calculation for each section. A 3D finite-element model was created in order to сarry out the calculation using ANSYS CFX. The number of elements was 21.8 million. SST turbulence model was used and the following properties of a real gas were specified: composition and dependences of its properties on the temperature. The total pressure and total temperature were set for the inlet boundary condition and the static pressure was set for the outlet condition. The following method was used for defining the local heat-transfer coefficient. Two calculations have been carried out for the model:
Visualization of the flow patterns obtained from three-dimensional calculation in the program ANSYS CFX, revealed a complex system of vortices The obtained flow picture is unusual for turbine blades and this fact also influences significantly on the usage of criterion dependences. Due to the abovementioned «abnormal» factors, in most cases the values of heat-transfer coefficient obtained using criterion dependences are much higher than the ones calculated using ANSYS CFX. The results obtained using ANSYS CFX have higher degree of confidence, because they were obtained using a verified method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. Balance of energy and coefficient of efficiency of aluminium air chemical current sources for aviation and space industries. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 104-109. This paper shows the estimated characteristics of electrochemical system based on oxygen acts as the oxidizer and the various most effective reducers or fuels. This work displays that the oxygen-aluminium system is most effective and promising to developed the electrochemical current sources (CSS) with high energy characteristics. In terms of theoretical value of energy density it trails only oxygen-hydrogen and oxygen- lithium systems. A mechanical rechargeable CCS with the aluminum anode (Aluminum-Air (AA) with an alkaline solution) is purposed for independent power supply for different techniques include aviation and space, for example the emergency power supply and for power supply the objects distant from the electric network. We provide the calculation of the energy characteristics for the AA CSS namely: the energy balance and the coefficient of efficiency. The energy balance is presented in form of the Sankeys diagram. It was accepted that the current forming reaction and the corrosion reaction are simultaneously run on the aluminum anode in alkaline solution and both of these reactions have a staging character. The thermal effects of all of these reactions were calculated and all possible mechanisms of the heat dissipation were shown. With purpose to form the estimated formulae of the coefficient of efficiency we have examined the mechanism of the chemical reactions in AA CSS and have used the polarization curves. This paper is the first to show that the formula for calculation the coefficient of efficiency is substantially different to the traditional one which is used now for CCS. The energy characteristics of AA CSS help to development the constructional characteristics and the optimal parameters of the independent power supply systems for aviation and others technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ahatov R. K., Chien H. V. Selection of reference base points during the determination of locating chart of the assembly unit. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 110-118. Automatization of the selection of the assembly datum surfaces during the design of the assembly tools requires finding an algorithm for searching and selection of reference base points according to the digital mock-up of the assembly unit, which was constructed in a CAD software system. The criterion for choosing the position setting spacing of the reference base points is the stiffness, which is defined by the admissible deformation wдоп. The value of wдоп is defined according to the following criteria: the finished component error; the assembly unit linkage errors; the errors of the base elements of the assembly tool. The work contains the classification, which was developed for the low-stiffness details of the airplane airframe structu re. The universal stiffness characteristic D was defined for each type of details. The value of this characteristic depends on the geometrical, physical and mechanical properties of the standard details. D describes the ability of the structure of the standard components to withstand the external loads. For example, the stiffness characteristic of the structure of a plate-type detail is defined by the following formula: This allows to determine the maximum deflection of the plate under its own weight The comparison of the maximum allowable deflection wmax with the admissible deformation wдоп allows to define the maximum spacing of position settingof the reference base points or the installation pitch of base fixing members via the following formula: The problem of definition of lmax for other standard components is solved in a similar way. These components include the following:
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Rusyaev N. N., Spiridonov S. V. Nanowires defects, investigation of opportunity of early detection. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 119-124. This paper is devoted to investigation of possibility of defect detection in nanoconductors based on their transport property changes. The detection of nanodefects is a significant challenge, because it requires studying each individual sample along all stages of the engineering process. For effective checkout of the produced devices parameters there is a need for more fast, simple, and productive means for the defect detection. In this paper we investigate the possibility of detecting nanodefects according to their manifestation in the transport properties of a conductor. One of the possible types of such defects is the «conductor-defect-conductor» transition where the defect represents a suspended one- dimensional chain of atoms. The reason for studying defects of this type is rather high probability of emergence of such defects during operation under the mechanical or thermal impacts, and the possibility of occurrence of such defects in various manufacturing processes. The investigation was performed by mathematical modeling under Atomistix Virtual Nano Lab software. For the calculations we used two theoretical methods: EHT (Extended Huckel) and the method of Classic Potential. Based on these methods the models of defect-free and defective conductors were developed. The defect in these models was considered as an approximation to the model of a partial break of a conductor. The parameters for the comparative analysis included following characteristics: the difference of electron density, the difference of electrostatic potentials, molecular spectra, current-voltage curves. The measurements were performed on the two-electrode scheme with external voltage varying in the range from −2 to 2 V. Comparative analysis of the electronic structures and transport properties showed that there were differences sufficient enough for defect detection based on current-voltage characteristic changes. Nevertheless, it is necessary to keep in mind that we have investigated only one type of such nanodefects. In our case the defect conductive chain was considered to be perpendicular to main conductor side, and to have only methods for studying other types of defects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Busurin V. I., Korobkov V. V., Zheglov M. A., Akhlamov P. S. Research of the influence of acceleration on the pressure sensors based on optical tunneling effect. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 125-133. Purpose Measurement of pressure and force in aggressive eenvironment and high temperature conditions typical for aviation and space power plant operation, in particular aviation engines, can be implemented by quartz transducer based on optical tunneling effect (OTE). Design/methodology/approach Typical quartz pressure transducer based on OTE consists of reflecting quartz prism, quartz sensor element (membrane), source of light emission, light receiver and processor. Measuring the value of the gap between quartz prism and quartz membrane provides information about pressure in the environment under control. Beam fixed at one end or beam fixed at both ends can be used as a sensor elements in quartz force transducer based on OTE, which consists of the same elements as the quartz pressure transducer and has the same method of measurement. Findings Some aspects of acceleration influence on the sensor elements of quartz pressure transducer based on OTE are considered in this article. It was shown that the reflectivity of the sensor element of quartz pressure transducer and its output parameters depend on the measurement range, design parameters of the sensor element, and the initial value of the gap between the quartz prism and quartz membrane. In particular the bigger the initial gap is, the smaller the influence of acceleration on the output parameters of quartz pressure transducer based on OTE. On the other hand a big initial gap has negative influence on pressure sensitivity. The graphs of correlation between the size of the gap and the value of acceleration were drawn. The gap calculation formula includes the quartz parameters such as Youngs modulus and Poissons ratio. Originality/value The additional error due to impact of acceleration on the quartz pressure transducer based on OTE was calculated and its value was about 0,01%. The calculations were performed for different design parameters of sensor elements and measurement ranges. According to the results obtained it can be concluded that such transducers can be used in aviation engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khayrnasov K. Z. Modeling and thermal analysis of electronic devices on board space vehicles. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 134-138. Purpose In this paper, the methodology of thermal calculation of the electronic devices forspacecrafts operating in a vacuum is developed. Thermal analysis of real electronic devices was produced and the effect of the thickness of the intermediate copper layers of multilayer printed circuit boards (ML PCB)was examined for the removal of extra heat from electronic components. Design/methodology/approach An electronic device was modeled by means CAD-system CATIA and was solved with finite element method (FEM) and compared with solution obtained via analytical methods. Findings The study and mathematical modeling of thermal modes of electronic modules, operating in compartments of the spacecraft, performed by FEM, showed that the addition in the ML PCBextra layers of copper provides required temperatures of the electronic devices. The dependence of electronic devices temperature from the thickness of the intermediate copper layer was determined and the optimum thickness of intermediate layers was received. Reliability of the results obtained in CATIA was repeatedly tested on the test examples. In the present study, the accuracy of the calculations was checked by thickening the finite element mesh. Practical implications Mathematical models and the results of modeling of heat transfer processes obtained in this paper can be used as a practical guide for thermal design of new equipment. Originality/value Optimal value can be accepted for thickness of the intermediate copper layers of ML PCB.The value of this work lies in the practical application of research results to the design of equipment used in the space | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voronina L. N. Analysis of parameters disorders influence on operating mode of multimodular inverters. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 139-144. The parallel work of single-phase current-controlled inverters and the way for maintenance the uniform current distribution between them is considered in the paper. The purpose of work consists in the elimination of disorders influence of inverters components while they perform in-parallel. Structural, functional and technical decisions for maintenance the uniform current distribution in inverters have been developed while some methods of electric circuit theory, theories automatic operation, differential and integrated calculations and the concept of multichannel transformation of a power stream were used. Mathematical research of working processes in inverters working in-parallel was spent by means of imitating computer modeling in OrCAD environment. The computer model of in parallel connected current-controlled inverters has been developed and nominal and emergency modes of their work are considered. On the basis of computer modeling, the analysis and check of working capacity of the offered method for maintenance the uniform current distribution are led; its comparative efficiency is described. The results received during work have practical value. The developed computer models of single-phase converters allow to reduce time for research and analysis of working processes taken place in the devices. The offered way solves one of the basic problems arising at designing of multimodular inverters — uniform current distribution to loading simultaneously with the safety of converters work in emergency operation raises. The given method could raise quality of the electric power acting to the consumer. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsov D. A., Turchenko I. S. Single-winding saturable inductors in airborne secondary power supplies. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 145-153. During last decade foreign manufacturers were displaying an increasing interest in application of modern soft magnetic materials for saturable inductors, used as components of airborne electrical equipment, that was demonstrated in scientific-technical publications. Nowadays, amorphous and nanocrystalline alloys have such advantages as very narrow hysteresis loop and reduced eddy current losses, lower weight and volume, enhanced stability of magnetic properties, extended operational temperature range in comparison with conventional crystalline materials that make it possible to design saturable inductors with higher operational characteristics. This fact allows for combining in modern converting devices based on saturable inductors the merits of their traditional magnetic controlled predecessors, such as easy fabrication and high reliability, low level of interferences radiated, and improved weight, size and energy characteristics. The principle of saturable inductor operation is based on switching between unsaturated and saturated states of a magnetic core. When the core is saturated and the inductor is conducting electric current as the magnetic switch, which is «on». When the core is unsaturated, the inductor is «off». The single-winding saturable inductor contains only one winding, which is used as an operating one in the first half-cycle of the supply voltage, and as a controlling one in the second half-cycle of the supply voltage. The application of such inductors enables to improve the manufacturability, reliability of the items, and decreases the cost of devices, based on them. Authors have proposed new circuitries of regulated single-phase rectifying devices, in which the output voltage is controlled by two single-winding saturable inductors, operating in both DC and AC circuits of the rectifier. The features of the proposed circuitries are as follows:
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Grumondz V. T., Polishcuk M. A. The algorithm of generation of the initial states set for the launch of the gliding unmanned aerial vehicle in the problem of attainability of the given set of navigation points. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 154-159. The paper considers a gliding unmanned aerial vehicle (UAV), which is equipped with a high-aspect- ratio wing and pneumatic control actuators. These elements make the long-range flight of the UAV possible. The UAV is the newest aircraft type with improved efficiency. The paper considers the problem of selection of aerodynamic and dynamic configuration of the gliding UAV. This selection should provide a substantial improvement of the flight performance and dynamic characteristics of the analyzed gliding UAV. The task is solved by the usage of the configuration elements, which can be regarded as new for the UAV design practice. These elements include a high-aspect-ratio wing and pneumatic control actuators. The mathematical model of the UAV motion and the problem solution algorithm for all path segments were created. The aerodynamic characteristics of the wing were chosen. Together with the control algorithm these characteristics provide maximization of the projected length of the UAV flight path onto a horizontal plane (in particular case, maximization of the actual flight range). The parameters of the angle stabilization and target guidance system were chosen as well. The algorithm for the solution of the mentioned above problems under additional conditions was created. These additional conditions include the following: the requirement for flying over the arbitrarily assigned set of navigation points on the earths surface; the task of maximization of the absolute values of the flight path angle at the end of the trajectory (target approach). Such research is topical for many practical problems of UAV target guidance. The results show that the maximum flight range can be increased by at least 75% compared to that of the existing modern Russian analogues. The paper considers the problem of construction of the algorithm for generation of the initial state set for the launch of gliding UAV from the carrier. This problem is considered as a part of a task of providing attainability of the given set of navigation points for the designed UAV. One of the points of this set is the target point. The above mentioned task takes into account the constraint of the maximum value of the total energy of the UAV, which is transferred to it at the moment of launch. The paper also shows the dependency of the parameters of the initial state set on the number of navigation points and their location on the earths surface. The complexity of this problem is rather high due to the given set of navigation points. This complexity is the main difference between the presented algorithm and algorithms that were used in the standard situations. This paper serves as a continuation of papers [1] and [4]. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Barabin G. V., Gusev V. Y., Zaitsev V. E., Yurov N. N. Combined methods of radiometric correction of typical artifacts on satellite images. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 160-165.. Purpose The aim is to create new methods for correcting brightness distortions in the satellite images. The distortions caused by non-uniformity of the sensitivity of photo detectors, or faulty settings. This is shown in the image in the form of vertical stripes. This method needs to be robust to work with images with very high natural changes in brightness caused by different types of terrain and clouds. Design/methodology/approach Proposed two-stage correction methods that take into consideration local characteristics of the image. First stage provides good local correction by taking into consideration local characteristics of image. Second stage provides global control of a general change in brightness across the whole image. Findings The methods of removing the vertical stripes on the images with higher reliability due to additional compensation after the first stage of processing. Methods take into consideration the local statistical characteristics of the columns, which allows for smooth adjustment and reduce the impact on the determination of the quantities of natural changes in brightness adjustments due to the terrain. Additional control using moving average of the average brightness of the columns to match the original and the corrected image eliminates the possibility of incorrect correction on a global scale. Another advantage of the proposed methods for processing satellite images of large size is their low time complexity that is linearly dependent on the number of columns. Research limitations/implications The methods can be applied at the stage of initial processing of satellite images for automatic correction of vertical stripes. Methods belong to the level of processing 1B according to international classification, which includes radiometric correction and geometric correction of systematic errors of CCD sensors scanning system. Originality/value Many existing methods for brightness adjustment on the columns are not ideal, and not always able to take into account the strong natural variations in the brightness of the image because of the terrain or clouds. Suggested methods, thanks to the local image analysis, image processing make it possible to significantly dissimilar in texture and brightness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eskin V. I., Sudakov V. A. Hybrid method of forming preferences function in computerized decision support systems. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 166-172. The main purpose of this work is the construction of the preference functions formation method that allows to take into account the dependence of preferences that does not require a significant investment of time to build a user preference functions, working with vector criterion of arbitrary dimension. The original method for hybrid functions preferences formation is proposed. The user selects disjoint regions in the space of criteria. For each of these areas the user sets a preference value of the level in the scale of preferences, which set strict preference relation. Then a set of convex criteria space subregions is constructed in automatic mode according the next conditions: they do not overlap with the areas specified, and the union of all subdomains formed with source areas provides a complete criteria space. Next, using the concept of Pareto dominance and a number of other methods of determining dominance we can define a preference relation between the areas specified by the user, and the areas identified automatically. The next step is to build a directed graph whose vertices correspond to the regions and the edges are the preference relation for vertices. Next, the user needs to disassemble the graph similar to that suggested in Larichev ZAPROS method. In some practical problems of ranking alternatives several non-dominated alternatives often fall into one area, so that a their relation must be defined. In this case the user should either divide this area into smaller ones, or use the formal (quantitative) method of comparing alternatives within a given area. A function to compute the total value of preferences is called a hybrid function of preferences (HFP). Currently, we implement the interface for specified HFP method in C # and ASP.NET. Initial data are stored and processed in DSS database under control of MS SQL. The above method of constructing hybrid preference functions allows one to take into account the dependence on the preferences, provides the required accuracy of decision support, contains a fast iterative procedure for entering and editing preferences. The method is invariant with respect to the subject area, it is planned to use in tasks ranging applications for scientific and applied research on the Russian segment of the International Space Station. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nerubailo B. V., Vu X. D. Differential equations for physically orthotropic and isotropic cylindrical shells under action of longitudinal. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 173-185. The article is devoted to an actual problem from the field of strength of aviation and rocket-cosmic thin- walled constructions such as solution to the boundary problems for definition of their stress-deformed state on the basis of high definition of differential equations in the partial derivatives. An object for investigations is the circle cylindrical shells made from a material which has different elastic properties in the three mutually perpendicular directions, videlicet the physically orthotropic cylindrical shells. Under action of arbitrarily changing on shell surface longitudinal load the high defining differential equations in the partial derivatives of general theory for the physically orthotropic shells which are most often meeting among anisotropic thin-walled constructions were obtained for the first time in this article. From sufficiently great varieties of initial equalities of shells theory the Vlassovs version was sel ected by the authors as the most consistent fr om the viewpoint of energy- static principles observance. In particular, the Bettis equalities for reciprocity of work are exactly executed and it causes the symmetry of three equations system in displacements for the theory of shells. Thus, in the article the Vlassovs general theory of isotropic cylindrical shells is firstly generalized for the case of the physically orthotropic shells and the new differential equations are obtained. Since the integration of the eight defining differential equations in the partial derivatives of the general theory for the physically orthotropic shells is a great problem the simplification was made in the article on the basis of variability confrontation principle of stress-deformed states in axis and circle directions (Novogilovs criterion). As a result, there were obtained the new differential equations in the partial derivatives such as «gently sloping shells type» of equations passing into the Vlassov-Donnells equations in the case of isotropic shells, «semimomentless theory type» of equations passing into the widely well-known Vlassovs equations in the case of isotropic shells, as well as the equations for the tangential stress-deformed state with very high variability — plane problem analogue of elasticity theory. On the basis of asymptotic errors for the mentioned here approximate equations three methods of asymptotic synthesis of the shells stress state were formulated for the concrete problem considering in the article and two of their give possibility to make the asymptotically exact solutions. On the basis of the obtained differential equations the boundary problems for the infinite long closed cylindrical shells under action of axial local loads are considering. The differential equations of the general theory and approximate theories of shells are applying for solution to these problems by Fouriers integral method. In the equations case of the semimomentless theory and tangential stress state the analytical solutions and simple formulae for important unknown quantities were obtained as results of improper integrals taking. Some results of calculating represented in the graphic form showing the influence of loading kind and orthotropic parameter on the stress-deformed state of shells. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Blinkova A. Y., Blinkov Y. A., Mogilevich L. I. Non-linear waves in cylinder shells with viscous incompressible liquid inside, in consideration of energy dissipation. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 186-195. An equation for nonlinear waves propagating in cylindrical shells containing viscous liquids is derived. Both the geometrical and physical nonlinearity for the shell as well as the energy dissipation are taken into account. The viscous liquid model is used. The nonlinear boundary value problem of coupled hydroelasti city is formulated and solved on the basis of the asymptotic approach. The models of structural damping in the material of the shell and of the viscoelastic material of the shell were considered. It is shown that both of them lead to one and the same equation which generalizes the well-known modified Korteweg-de Vries-Burgers equation. The new term describing the liquid impact inside the shell is introduced. The equations of viscous incompressible liquid are asymptotically reduced to the classical equation of hydrodynamic lubrication theory. This simplification becomes possible when the radius of the shell midsurface is significantly smaller than the deformation wavelength. In the absence of liquid the equation has a known exact solution, which can be considered as an initial condition for the numerical solution of the equation described above. This paper describes the numerical solution of the Cauchy problem for the shells dynamic equation considering the effect of the liquid. This approach to the formulation of the finite-difference schema is based on the construction of the predetermined system of differential equations derived from the integral approximation of conservation laws and the integral relations between the unknown functions and their derivatives. As a result, the finite-difference schema is defined as a condition for the compatibility for the system and the resulting difference schema automatically secures the fulfillment of the integral conservation laws in the areas compounded from the basic finite volumes. The presence of liquid inside the shell leads to a substantial change of the longitudinal deformation waves propagation. In the abscence of the liquid in the shell a solitary wave (kink-antikink) moves retaining its original shape and velocity. The presence of fluid in shells made from the materials with Poisson ratio less than 0.5 results the exponential increasing of the wave amplitude under small time magnitudes and the absence of wave oscillations at the forefront, which is due to the energy dissipation. In the absence of energy dissipation the oscillations at the leading wave front occur. It can be stated that the fluid contributes to a constant extra «feeding» energy from the original excitation source that provides the growth of amplitudes. Consequently, the use of the proposed models increases the possibilities of experimental data analysis during the investigation of various systems like the fuel supply, the cooling, the blood and lymph stream pulsating waves and etc. which dynamics can be only by nonlinear models described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bogdanov V. R., Sulym G. T. A modelling of plastic deformations growth under impact, based on a numerical solution of the plane stress state problem. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 196-204. A new finite-difference method of numerical solution for dynamic plane problems of elastic-plasticity theory taking into account unloading processes is proposed. A plane stress state for the three-point bar bending is considered and some solutions for the bars with rectangular cross-sections and the middle notch modeling the crack have been obtained. The plastic strain areas around the crack tips in different alloys are compared. The considered specimen is loaded by the impact of the absolutely rigid striker. Due to the short interaction time the dynamic load can be approximated by the pressure at the contact area varying in time as a linear function. Both the contact and bearing areas are constant. The theory of non-isothermal flow of strengthening plastic media, the Huber-Mizes yield criteria, and the hypothesis of short-term creep are used. We also suppose that the material is strengthening during the elastic-plastic deformation process. The successive approximation approach is used for the physically nonlinear problems solution together with the variable- step finite difference schema. The numerical solutions are computed for compact specimens made of RPV steel 15Х2НМФА, aluminum, titanium and silver. The areas of plastic deformations at the top of the notch-crack for the alloys with different shear and bulk modulus are compared. It is shown that rising of the ratio between the shear and bulk modulus results rising of plastic zones at the top of crack-notches. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reviznikov D. L., Sposobin A. V. Computation of the polydisperse supersonic flow around bodies. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 205-211. The improvement of the method of the numerical simulation of dust-loaded supersonic flows around bodies is presented. The polydisperse supersonic flows are considered. The effect of the interaction of different-size particles to mass and energy flows in disperse phases to streamlined bodies surfaces is analyzed.
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Khromatov V. E., Golubeva T. N. Vibrations and stability of a ferromagnetic cylindrical shell in a magnetic field. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 212-219. Purpose Vibrations of closed ferromagnetic cylindrical shells in magnetic fields produced by direct currents flowing along shells axes of rotation were investigated. Design/methodology/approach Using the basic assumptions of the classical theory of cylindrical shells and the theory of magnetoelasticity the natural frequencies of the magnetically soft ferromagnetic cylindrical shell in the magnetic field were computed. The effect of the magnetic field to shells natural frequencies was investigated numerically on the basis of Mathcad software. Findings The main results of investigations of the effect of magnetic fields to natural frequencies of diamagnetic, paramagnetic and ferromagnetic thin plates and shells are reviewed. The governing equations of vibrations ofcylindrical shells in azimuthal magnetic fields of the direct axial current are derived. The main relationships for natural frequencies of circular cylindrical shells in magnetic fields and the ratio of external magnetic field resulting to static stability loss of the shell are obtained. It is shown that magnetic fields decrease ferromagnetic and nonmagnetic shells natural frequencies. Practical implications Structural design of aircrafts requires the information about natural frequencies needed to tune out from resonance and to estimate the influence of magnetic fields on the vibration and stability of cylindrical shells. Originality/value On the basis of mathematical models of magnetoelastic vibrations of thin-walled structural elements and Borland Delphi 7.0 software, universal software for the computation of natural frequencies of plates and shells in magnetic fields was constructed | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golubev S. I. Some peculiarities of the market environment of the military-industrial complex for the russian aircraft manufacturers. Aerospace MAI Journal, 2013, vol. 20, no 3, pp. 220-228. The article is touching the theoretical foundations of strategic management, suitable concept of competitive strategy of the military-industrial complex (MIC) of the Russian Federation and the practical basis for its implementation. The most preferred core competitive strategy for the MIC of the Russian Federation should considered differentiation. The defining feature of the defense industry products competitiveness is innovation, which, in turn, relies on the ability of the productive forces to implement in the product develop improvements, including, above all, technical innovations related to the technical level of the product. The concept of differentiation is supported by the whole design process, which is targeted to the ability of the aircraft (AC) to perform exclusive operational needs. This ability is the core competitiveness of the AC. The competitiveness of a manufacture in the article is understood as an ability to produce products and services that better meet demands and needs of potential and existing customers compared to competitors offerings. Strategy of manufactures working in the area of MIC is considered within framework of Porters models of Five competitive forces and Base strategies that are leadership in costs and expenses, differentiation and focus on narrow segment of the market. The differentiation should be considered most appropriate based strategy for aircraft manufactures of Russian MIC. Supporting this idea the article suggests several practical steps in the areas of integration of science, education and manufacturing companies improving competitiveness of new aircrafts; social influence; and tasks of strategic management at MIC enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goriachev O. V., Efromeev A. G., Minchuk S. V. Mechatronic module design methods for the correction systems of the aerial vehicle rotating about its longitudinal axis. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 7-15. Purpose The main goal of missile modernization is to increase their efficiency. Design/Methodology/Approach Novel flight trajectory correction system design techniques of ground-launched and air-launched unguided missiles are described. The proposed approaches are based on mathematical BLDC motor models which obtained with magnetic field calculation by the finite element method. Findings The developed control system of the air-launched missiles includes the correction filter with the algorithm based on current and temperature of the motor windings. The created control system of the ground-launched missiles includes the observer and the non-linear correction filter for compensation of the influence of the transport delay in the navigation system. Originality Mechatronic units design techniques for trajectory correction systems for ground-based and air-based rotating unguided missiles are offered. The forced operating mode of the drive and delays of feedback signals are considered in these techniques. Restrictions The offered techniques dont allow to design long operating mode systems and systems with actuator other than BLDC motor. Also these techniques dont allow to design drive for trajectory correction systems for roll-stabilized missiles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nemoudryi K. V. Research on the problem of regional aircraft shortage in Russian civil aviation. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 16-20. Purpose The paper aims at exploring the problem of regional aircraft shortage, which airline companies face in their professional activity. Design/methodology/approach The appropriate information on the topic was collected, summarized and structured to analyze the problem. This analysis was supplemented with the opinion of the author and experts. Conclusions and remarks were made on the basis of the collected data. Findings Today there are basically no alternative means of transportation besides airline service within the territories of Far North, Republic of Sakha (Yakutia), Khanty-Mansiisk Autonomous Region, Yamalo-Nenets Autonomous Region, Nenets Autonomous Region, Kamchatka Krai and other territories of the North-Western, Ural, Siberian and Far Eastern Federal Districts. Russian airline companies actively used USSR- and Russian-produced aircraft during the last twenty years. However, there is a huge negative impact from stagnation in aircraft industry, which was caused by political and economic crises as well as prohibition on operation of certain aircraft after flight accidents in 2010-2011. This situation caused a massive reduction of aircraft and rotorcraft fleet. Russian aircraft companies lost their expertise and professional personnel during the last twenty years. The equipment and technologies became obsolete and functionally deteriorated. According to the forecasts of State Research Institute of Civil Aviation (GOSNII GA) and Saint-Petersburg University of Civil Aviation, the demand for new types of passenger aircraft with the capacity of 10-85 seats and flight range 500-1500 km will exceed 250 items by 2016. Thus the demand will amount up to 2,8 billion USD in monetary terms. Joint-production with foreign producing partners might become one of the effective ways of eliminating the regional aircraft shortage. It will offer the possibility of starting planning and producing as soon as possible as well as allow involving modern world-class technologies. The optimal characteristics of a regional aircraft for Russian airline companies are the following:
The problem of regional aircraft shortage is one of the most relevant transportation issues of today. It is impossible to organize transportation without the appropriate means. Failure to take effective measures can lead to serious irreversible consequences. These include discontinuation of operation of regional and commuter airline companies as well as serious negative socio-economic impacts on the regions themselves. The paper aspires to emphasize the importance of the abovementioned problems as well as offer ways of solving them. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sypalo K. I., Podogova A. A. On-line high speed flying vehicle aerodynamics performance identification. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 21-32. Purpose It is known, that the statistical uncertainty of the high speed vehicle aerodynamic coefficients due to wind-tunnel test complexity can be significant. In fact this uncertainty can reach value of 40 percents from nominal one. As the result there is necessity to identify these coefficients during the flight, i.e. on-line. Practically, such opportunity is arising only at the passive flight stage. High speed vehicle basic aerodynamics performance on-line identification algorithm is under consideration. Approach This identification algorithm is utilized at vehicle passive flight stage and it is operating simultaneously with onboard navigation system, which generates extended phase vector components estimations The main specific feature of suggested onboard integrated system architecture consists in so called series-parallel operation of both navigation and identification algorithms. More detail, estimation of extended phase vector one considers as prior data for identification algorithm, which processes data of inertial sensors, attack angle sensor, as well as air speed sensor. The output of identification algorithm is estimation of the vehicle aerodynamic coefficients vector, which is used later on for both trajectory and attitude control systems operation. Brief overview of the research procedure Mathematical simulation is used for suggested algorithms accuracy estimation. The specific software complex has been developed for such simulation performing. Measurement errors, as well as prior aerodynamic coefficients uncertainty have been considered as uncontrollable factors. Findings Analysis of the simulation results demonstrates the opportunity to reduce prior coefficient uncertainty from 30 percents till to 10-12 percents, applying to both drug and lift forces coefficients, and from 30 percents till to 20 percents applying to aerodynamic moment coefficients. Practical implications Result obtained can be utilized by high speed vehicle onboard integrated navigation & control system design and development. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komissarenko A. I. Determination of rockets angular position in relation to engine thrust misalignment during the rotation depending on random law. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 33-40. It is known that engine misalignment takes a special place in missile distribution. The rocket is twisted around longitudinal axis in order to avoid a significant dispersion. Since stability of missiles is achieved by means of aerodynamics, the twist around longitudinal axis is known as rotational movement along the axis. Rocket rotation is implemented with the help of skewed blades while missile is moving in the transport-launch container and with the help of stabilizers (wings) angled to the longitudinal axis. Rocket rotation significantly reduces the dispersion. This article presents issues connected with analytical determination of missile angular position such as velocity vector angle and slide angle depending on the value of angular spinning velocity. Rotation in this article is replaced by sinusoidal disturbance, because of the fact that in general it is not possible to determine the missile angular position in closed form by means of summarized rotation from the skewed blades while the missile is moving inside the transport-launch container and from skewed stabilizers, wings. The solution to this problem is divided into separate stages which are multiple of sinusoidal influence half-periods. The disturbance from half-periods is replaced by an average integral value. As result, a general solution to the task of the velocity vector angular position and slide angle determination is obtained. The results are used in the theoretical and experimental research. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panchukov A. A. The use of approximate motion models for solving boundary value problems in astrodynamics. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 41-48. The feature that characterizes boundary value problems in astrodynamics is the absence of an analytical relation between arguments and terminal functions. Such relation can only be obtained through numerical integration of a system of differential motion equations, which makes it difficult to determine an initial approximation guaranteeing convergence of the iterative process of the search for solution to a system of non-linear equations, and the process becomes very time-consuming. That is the reason for widespread use of this method, which is based on approximate motion models being used for searching an initial approximation of the arguments vector and its subsequent updating. The use of method proposed in this paper does not require a numerical calculation of partial derivatives matrix of terminal conditions vector with respect to arguments of boundary value problem, while the search for and correction of the initial approximation can be performed using the same algorithm. Algorithms for approximate motion models are systematically used for solving the flight profile synthesis problems in this method. The universally used method for solving boundary value problems in maneuvering in their precise statement is the method of searching for a vector of arguments and correcting it in order to minimize boundary condition errors on the basis of relations for approximate model of motion. It is justified to use the spectral radius value of the iteration process matrix in order to evaluate conditions for the method convergence. The paper analyses the factors affecting to the method convergence. Numerical estimates have been obtained for the applicability of the model of motion along orbits that are close to circular orbits for correction of misses when solving maneuvering problems for low-flying SC. To solve the problems of maneuvering in open intermediate orbits the ballistic coefficient was used as parameters of the precise computational model and the value reciprocal to the thrust vector modulus, because the approximate model has pulsed approximation of the trajectory powered portions in addition to the fact that the atmospheric drag was not taken into account. The described technique had turned out to be effective up to conditions where solution didnt exist because of physical constraints. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shklyarchuk F. N., Rei Juhnbum . . Calculation of non-axisymmetric vibrations of shells of revolution with liquid by finite element method. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 49-58. The new variant of finite element method (FEM) is developed for calculation of arbitrary orthotropic elastic shells of revolution partially filled with ideal incompressible liquid. The compound shells are connected with ring ribs. The preliminary axisymmetirc stress-strain state of the shells is taken into account. The displacements of the shell and liquid are considered in the form of the n-th harmonic in the circumferential direction. The shell is divided on narrow conical belts which together with the contained in them lays of the liquid are considered as finite elements (FE). The tangential displacements of a FE shell are approximated by linear functions of the meridional coordinate and the normal displacement — by a full cubic polynomial. The axial displacement of a thin FE lay of the liquid is approximated by a power function multiplied by a linear function of the axial coordinate x. The radial and circumferential displacements of the liquid are obtained from the exact solution to the equation of continuity with the kinematic boundary condition on the shell surface and expressed in terms of the elastic shell normal displacement and the axial displacement of the liquid. The axial displacements of the liquid are excluded as cyclic coordinates and the liquid is represented by matrix of apparent masses. The shell pole is replaced by a rigid plate or orifice of rather small radius. Examples of calculations of the non-axisymmetric mode frequencies of the truncated conical shell and hemispherical shell filled with liquid are considered. The obtained results are in good agreement with the knownanalytical and experimental results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Usovik I. V., Grishin V. M. Method of active loaded reservation structure synthesis based on optimization of increments of multiplicative faultlessness criteria. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 59-71. This paper is devoted to the increase of system reliability in aerospace field. It is focused on the search of new methods for synthesis of reservation systems structures, which consist of a large number of elements. The new method for finding optimal structure of active loaded block reservation of space-aviation systems and their subsystems, which provide maximum reliability, is considered in this paper. Both active and passive (constant) reservations consume resources of backup elements. The application of active loaded reservation is often explained by the fact that parameters of the system do not change in case of failure. For example, in cases when parameters of space control systems exceed acceptable values this may cause not only unacceptable changes of time and frequency characteristics, but also a loss of their stability. Moreover the loaded active reservation provides a constant readiness for the work of reserve elements, which is very important for aviation. The basis of this method is the creation of branches of the solution-search tree for synthesis task with the help of optimal structure from the previous step. At each step the branches of the tree are formed in such a way, that they keep properties of structures from previous branches and partially properties of adjacent ones. This method allows to develop a tree only in direction of the true solution and not to consider the other branches. The choice of optimal reservation structure of current step is made only from the scope of branches, which were obtained from optimal structure at the previous step. This paper considers properties of the proposed method, evaluates its computational complexity in comparison with the wave method and enumerating technique. The method is easy to use and it does not require creation of cumbersome model of graphs such as Deijkstra and wave method. Computational complexity of the method does not increase the polynomial of degree two of the system size. The number of elements in the main junction of unreserved system is used as the size of the system. Sizes of all blocks and the number of blocks in the reserved system are the optimized parameters. The given parameters of the system are: size (the number of elements in the system), reliability factors of elements in the system, reliability factor of switches, multiplication factor. Application examples of method for finding optimal structures of systems reservation with various characteristics are given in this paper. The method can be used for increase of large systems reliability and their large-size subsystems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I., Pronin O. Y., Radshenko A. V. Prediction algorithm for aviation products and space-rocket technics reliability at the design stage. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 72-79. Prototype models reliability of space-rocket products and aviation technics is characterized by probability of non-failure operation which is defined by the product of non-failure operation probabilities of all product components. The work purpose is the representation of some techniques for calculation of reliability indicators of elements and systems as available data on intensity refusals or with their absence. The high value of non-failure operation probability for certain service life is established in the development requirements specification for such products. For example, Р = 0,995 at confidential probability 0,8. The probability of sample non-failure operation should be proved by calculations and results of land tests. The actions providing reliability of elements with raised criticality should be developed. Predicted reliability of a product includes the probability estimations of non-failure operation of elements and systems during the operation modes with certain loading including mechanical (static, dynamic i.e. charges vibration with different frequencies, blow and another), electrical, thermal, radiating and other influences. In addition it is necessary to define reliability of elements and product systems in storage modes. Storage modes consider action of some various factors in both terrestrial and flight conditions. Elements of space-rocket technics in the majority are non-recoverable. One of requirements to the prototype models is application of typical and standardized knots and completing elements. Dimensional and mass characteristics restrictions or the best functional indicators force to use the foreign element base in certain cases. Approaches for definition of non-failure operation probability of some elements and systems are based on a design procedure for elements with known parameters of reliability. For example, purchased accessories contain data on failure rate either from elements passports, or THAT, or reliability directories. Definition of non-failure operation probability P is carried out with reference to exponential distribution law for great amount of non-recoverable elements of radio-electronic equipment. For the elements which do not have the official data on reliability definition of non-failure operation probability is carried out with the help of quantile — the representative parameter depending on a firmness stock of critical factor for the given element and also on possible variation of strength and other loading characteristics. The elements with knots produced by the developer of a prototype model, for example by МАI, are related to this type of elements. Calculation of some elements reliability can be performed by the third technique based on analogy to the elements, which have known parameters of reliability. The transformers in chains of the electrical discharge initiation, produced by МАI, can be related to these elements, like an ablaze pulse plasma propulsion (АPPP) given as example in this article. The standard variant of serially made transformers which reliability parameters are given in directories can be accepted for transformers as analogue. However they are different from ignition system transformers because they are not calculated for high-voltage impulsive loading. Therefore the parameter of reliability P for such transformers is defined with the help of both analogue according to the directories data and quantile by reference to the settlement stock of electric isolation firmness. The calculated value of non-failure operation probability is compared with the value given in product development requirements specification. In the further the elements making the greatest impact on reliability decrease are got out. The specified elements can be related to a category of critical ones. It is possible to improve the reliability parameters of elements having low values due to elements reservation and components duplication. Those elements which have no sufficient reliability data and elements which function as a part of engine in the modes different from passport should be marked as critical elements also. The chosen critical elements should pass through necessary volume of experimental lifelength. Created as a result of skilled design works the demanded high work reliability of aviation and space-rocket technics products can be provided by calculations of non-failure operation probability of all components and products, by analysis of critical elements and carrying out of actions for reliability increase at all stages of life cycle: designing, manufacturing and experimental operational development of prototype models. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveev Y. A., Kovalevskaya O. V. The analysis of negotiation process of design decisions during the parameters optimization of aircraft modification and replaceable subsystems. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 80-89. This article considers the problem of two-level conformity optimization for aircraft parameters and its subsystems. The method and algorithm for coherent optimization search of modification parameters of aircraft with solid propellant engine and replacement subsystems are presented in this article. The issues of design solutions harmonization are considered. The statistical method of conformity optimization for parameters search includes the following three main challenges. They are given below:
Results of design research on the top i-th level determine the areas of solutions to lower i+1-th level. The condition of consistency of design decisions: | miРБЗ(iП) − mi+1РБЗ(i+1П) | ≤ ∆m, where miРБЗ(iП) estimation of upper third stage mass obtained from the design model of the top (i +1-th) control level (with the task of parameters solving of aircraft modification optimization iП); mi+1РБЗ(i+1П) − mass estimation of upper third stage obtained on the based project of the lower (i +1-st) control level (at optimization parameter of upper third stage with restrictions); ∆m − defined small. It allows to carry out a process analysis of the based project harmonization for optimization of aircraft modification parameters and replaced subsystems. It is shown that the implementation of a coherent statistical method of optimization search allows to investigate the aircraft characteristics with taking into account peculiarities of design and technological solutions to interchangeable subsystems without the based project (without increasing the number of control parameters), while the estimates accuracy of mass characteristics modified by directed adaptation of the design model is increasing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y. Numerical simulation of chemically non-equilibrium flow in the nozzle of the liquid-propellant rocket engine. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 90-97. The object of research Chemically reacting flows in rocket nozzles. Theme Computational and theoretical study of chemical equilibrium and nonequilibrium flow in the nozzle of a liquid rocket engine Purpose The article aims are development of physical and mathematical models, computational algorithms and software system for the solution of the direct problem of the theory of the nozzle for the case chemically reacting flows and calculation of the parameters of chemical equilibrium and non-equilibrium flows, determination of the loss of specific impulse of the nozzle due to the chemical non-equilibrium, the concentration of toxic components. Method of investigation Mathematic modeling. Results Physical and mathematical models, computational algorithms and software package for solving the direct problem of the theory of the nozzle in the presence of non-equilibrium chemical reactions in the quasi stationary setting are obtained. Computational algorithm passing the singular point, which includes three stages and ensures that the condition of non-decreasing entropy is received. In the first stage the flow rate corresponding to the non-equilibrium flows in the nozzle where the regime «lock» the current was implemented (curve 1) and Mach number of the flow was, as close to one in subsonic flow (curve 2) was determined. In this case, all parameters of the flow along the curves 1 and 2 were almost identical up to a small neighborhood of the transition through the speed of sound. In the second stage, instead of the equation of conservation of momentum the constancy of the velocity Dependence of the speed (1-3) and the speed of sound (4) of the products of combustion from the longitudinal coordinates (1 mode «lock» the flow 2 subsonic flow regime, 3 passing the singular point) gradient was used, the calculation with which provided the condition of non-decreasing entropy. The appropriate starting point was taken on the curve 2. The solution was carried out to achieve supersonic flow and the condition of positivity of the velocity gradient, obtained from the conservation momentum equation of. In the third phase the direct problem for supersonic flow was solved. Numerical simulation of combustion unsymmetrical dimethyl hydrazine with nitrogen tetroxide in range of oxidant-fuel ratio 0.8 — 1.2, and the pressure in the combustion chamber 2 MPa - 20 MPa. Obtained The difference «non-equilibrium» flow rate from the «equilibrium», the value of specific impulse loss and the coordinates of the transonic at «non-equilibrium» flow are obtained. Field of application of the results and conclusions. Developed computational algorithms and computer programs can be used for designing advanced propulsion systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kotel'nikov V. A., Kotelnikov M. V., Morozov A. V. Mathematical modeling turning of a plasma stream expiring from the plasma thruster, in cross magnetic field. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 98-105. Research of turning plasma stream, expiring from electric propulsion, by cross magnetic field is discussed. The geometrical shape of a nozzle looks like an elongated rectangle. Thus the task in a phase space is four-dimensional, nonstationary and can be solved with use of mean power desktop computers. The mathematical model of a task corresponding to this physical model, includes the kinetic equations for ions and electrons (Vlasov equation) which are supplemented with a Poissons equation for a self-consistent electric field. The set of equations of Vlasov Poisson given to the dimensionless type was solved by method of serial iterations on time. For the numerical solution of the Vlasov kinetic equations the explicit scheme of Yu.M. Davidov method of large particle was used combined with a method of matrix prorace for solution of a Poisson equation on each time layer. The error of the chosen method of solution does not exceed several percent. Process model operation consisted of two stages. At the first stage it was simulated the kinetics of the stream which at the second stage got to a transversal magnetic field. The developed program code and the made numerous computing experiments allowed:
As a result of modeling, the cumulative distribution functions of the charged particles, fields of speeds, concentration of self-consistent electric fields in a plasma stream, depending on the parameters of a task (such as induction of a magnetic field; plasma flow rate on a nozzle cut; concentration of the charged particles; geometrical sizes of a nozzle; relations of temperatures of ions and electrons) were received. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gabrielyan D. A., Semenov V. V. Three-dimensional stationary magnetic field calculation of permanent magnet systems designed for thermomagnetic engine. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 106-113. Purpose The article aims are development recommendations for choosing the optimal magnetic systems (MS) used in thermomagnetic engines (TME) and solving the problem of its designing by computer simulation.Design/methodology/approach All calculations were performed by the finite element method (FEM) using the certified ANSYS Multiphysics 13.0 software package. Calculations are made both in two-dimensional and three-dimensional geometries. Considering magnetostatic calculation results of simplest magnetic system and operation principles of TME, that are based on magnetic phase transitions occurring in some ferromagnetic materials under the influence of the thermal impulse, authors develop recommendations for designing of the optimal magnetic systems. The set of calculations were performed to define a magnetic system that would satisfy these recommendations. Such magnetic system is presented and analyzed in the work.Findings Firstly, the calculation data show that the magnetostatic problem can be solved at a qualitative level quite well in the ANSYS software package. Secondly,the choice of permanent magnet (PM) should be guided by, at least, three factors: efficiency (would be good to create the most powerful MS), cost (the cost of the magnet increases with its size and power) and compactness. Thirdly, for performing effective operation of rotary thermomagnetic engine magnetic system have to provide the high values of magnetic induction in the working volume of the magnetic system and distribution of magnetic field has to obtain prolonged and continuous growth of the magnetic induction at the MS entrance and reduce action of magnetic force on the ferromagnetic working substance at the MS output. Such magnetic system was defined (fig.1).Fig.1. Defined model of magnetic system It satisfies all recommendations that were developed by authors of the work and has distribution of magnetic induction along the interpolar gap of MS as shown on a figure 2.Also, the optimizations of the opening angle and of the straight area length of this system were made. It was defined that optimal magnetic system for rotary TME is a system with opening angle α = 24 ÷ 34° and with straight area length l = 10 ÷ 15 mm.Research limitations/implications This research provides development of non-traditional methods of mechanical or electrical energy production based on thermomagnetic effects.Originality/value There is a lack of magnetic system designing data for thermomagnetic energy devices in literature. In descriptions of such devices simplest magnetic systems are used that have non-appropriate distributions of magnetic field in the working area. So, in recent work, using the computations with ANSYS software, the magnetic system models were optimized and recommendations for it designing were established. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bondareva N. V., Koroteev A. A., Samsonov A. B. Comparative analysis for the general operational properties of advanced actuating media for open systems of low-temperature heat release in space. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 114-120. The aim of this paper is to make comparative analysis for the basic performance characteristics of advanced working media potentially applicable for the open systems of low-temperature heat release in space. Primary requirements to such heat-transfer media include:
High-temperature LDRs are characterized by the top («hot») temperature of droplets near the generator of about 1000К. Liquid metals, tin in particular, may be used as a working medium in them due to the low saturated vapor pressure. Advantages of high-temperature radiators include: a possibility to reach high density for the released heat flow at the compact shroud sizes; practically total absence of the outer solar or planetary radiation influence on the efficiency of radiational cooling of droplets. And still the liquid-metal coolant application requires attacking many complicated problems related to the necessity for the structure thermostatting, chilled coolant transfer, development and operation of sophisticated shutoff and control equipment, etc. Operating temperature range of the low-temperature radiators is 300430К. The organosilicon fluids may be used as coolants in them. Such substances are characterized by the specific set of properties that can not be attributed to any other organic compound: low temperatures of glass-transition and slump loss meshed with the high thermal and thermo-oxidative stability (up to 250 °С and higher), very low saturated vapor pressure, low fugacity, and high resistance to radiation. As compared to the high-temperature radiators, the influence of outer solar radiation on the radiator performance appears to be rather high. This results in the necessity for some radiating area increase or proper consideration for the problem of optimum shroud orientation. Medium temperature range is characterized by operational temperatures from 450 K up to 650 К. Within this range it is possible to manage work process of relatively compact LDR with the heat output of 25 MW. The potentialities to use ion liquids for such radiators are being considered currently. Their basic advantages include practically total lack of evaporability in vacuum and capacity for increasing operational temperature up to 650 К. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A., Barykin I. Y. How shroud presence/absence at turbine rotary influences onto its appearance and efficiency loss. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 121-131. The way for calculating of how gaps and several parameters influence on to an efficiency loss of shroud-free turbine is presented. The mean diameter of the turbine is varied by (20 times, blades height by (36 times, profile chord by (5 times, other parameters are varied in a wide range. Graphical and mathematical relationships between efficiency loss and reduced complex parameter are presented for the shroud-free rotary. We try to apply the relationship obtained for shroud-free rotary to the rotary with the shroud, but our attempt is failed. We analyze works performed by K.M. Popov, M.Kh. Mukhtarov, et al., (CIAM) where it is examined of how reduced radial gap influences onto efficiency loss under shroud presence/absence at turbine rotary. It is shown that such approach describes improperly the picture for flows and efficiency loss in the turbines. By using the results of experiment-calculated investigations for turbines rotary with/without the shroud we develop the procedure for considering of how shroud presence/absence influences onto stage appearance and efficiency losses in it. The procedure is based on the existed generalized relationships according to two parameters: efficiency loss and complex reduced parameters, if admission is equal to 1. By means of the presented procedure it is shown that shroud presence/absence at the turbine rotary varies efficiency loss and complex reduced parameter. On the base of the regression equations generated for the blade of constant height, we reveal the relationships for efficiency loss in the turbine stage for a rotary with/without shroud. It is shown that during calculations the limit (choking) gap should be considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Misyutin R. Y., Levin A. V., Zhuravlev S. V., Zechikhin B. S. Automated engineering aircraft electric generator with permanent magnet excitation. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 132-139. In connection with increase of the electric-power systems capacity of the modern aircrafts the output power of aviation generators reaches several hundreds of kW. Their weight and size are considerably increased. In the article new effective constructive schemes of powerful electrical machines are considered. The analysis and modeling of powerful generators are more complicated. In this respect design automation based on modern computer technology has an important meaning. It provides better quality and reduces the design time through using of more exact computer models and numerical experiments. The algorithm of the design automation generators with permanent magnets is discussed. The algorithm is based on electromagnetic calculation of the synchronous generator active zone with taking into account of functional limit on mechanical strength and heating. The algorithm includes choosing generator geometry, electromagnetic loads and cooling system, structure of rotor permanent magnets (radial or tangential) and way of fixing of the magnets. The algorithm includes active zone dimensions based on preliminary electromagnetic simulation with taking into account mechanical strength and heating limit based on circuit theory. The calculations are carried out taking into account mechanical strength, deflection, rotor critical speed considering magnetic attraction force and heating of constructional details. Choice of electromagnetic loads and analysis of the stator active zone are based on experience of the design of traditional aviation generators. The rational type of rotor magnetic system and way of fixing magnets, providing the essential mechanical strength is determined on the basis of comparative computation according to the criterion of the generator minimum weight. Based on finite-element method the results of the generator preliminary computation are refined and the research of the sleeve mechanical strength and other parts of magnets fixing, deflection and critical speed, heating of generator certain parts are made and generator dimensions are specified. Algorithm and programs of finite-element modeling are based on the program complexes and materials database and typical constructional details of aviation generators with permanent magnets and they are part of the permanent magnets generators automation system design. The results of finite-element modeling of the rotors critical speeds, the calculations of strength characteristics of various types of sleeves and design, the estimation of the increase of the rotor and stator magnetic attraction force due to the presence of eccentricity, and other electromagnetic, mechanical and heat calculations are presented in the article. It is shown that computer technologies based on the proposed algorithm allow to create the basis of the design automation method of aviation generators with permanent magnets. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlova N. V., Vidov K. S., Gusev D. I., Kharchenko D. N. Source data processing for safety provision of aircrafts in formation flight. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 140-148. This paper is focused on a problem of air collision prevention during rendezvous and join phases of formation flight by means of formation flight informational support and automation. A possible air collision problem solution consists of three main stages:
To perform leader and wingman aircrafts pilots informational support during rendezvous and join phases of formation flight possible variants of indication are suggested. Both pilots have an opportunity to watch multifunctional displays determined wingman aircraft rendezvous flight paths and correct them. Determination of rendezvous flight path is based on use of combination of modified pursuit-course and pure collision guidance methods. They perform efficient and reliable solution of rendezvous task. Collision prevention is under control algorithm that performs estimation of collision prerequisites and computation of control commands to avoid intersections with safety zones of one or more aircrafts considering boundary conditions for control parameters. Simulation results validate the acceptability of the presented in this paper solution of air collision prevention problem during rendezvous and join phases of formation flight. The results presented in this paper are the foundation for further research and development. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Konstantinov G. S., Kuvshinov V. M., Kuznetsov I. P., Parshin A. A., Redko P. G., Steblinkin A. I., Khaletsky L. V. Power-by-wire flight control actuators development prospects and issues. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 149-160. Object and purpose of the study Object of the study is flight control actuation systems (FCAS) for next-generation aircrafts based on energy-saving technologies that are potentially able to provide flight quality and safety ratings significant increase as well as aircraft operation and exploitation overall cost savings and its ecological environment improvement. Electro-mechanical (EMA) and electro-hydrostatic (EHA) actuation are well known among these technologies. Meanwhile the use of such technologies on modern aircrafts is limited despite of their profits.Electrical actuation technology implementation in modern FCAS influence on overall aircraft safety is the purposes of the study. Methodology The common requirements to the traditional electrohydraulic actuator characteristics were used to confront them with characteristics achievable with the present electric actuation technologies (EMA and EHA of different types). These technologies were observed with regard to its safety ratings and dynamic characteristics especially at low input signals (Uin<0,2%Umax).New type of EHA with combined control of rod velocity was developed by specialists of Voskhod, Moscow aviation institute, Sukhoi and TsAGI. Developed EHA was tested on special testbench for actuators external loading in TsAGI. Mathematical modelling of closed control loop «Aircraft — Flight control system - Electric actuator» was done to examine developed EHA for primary flight surface deflecting in comparison with traditional electrohydraulic actuator and traditional EHA (motor control). The modelling process was done in MATLAB/Simulink software both for maneuverable and non-maneuverable aircrafts with applying wing disturbances of different velocity (W<4 m/s and W>4 m/s) obtaining aircraft stability margins and flight qualities. Findings EMA can only be used at present time in FCAS for deflecting secondary flight surfaces (spoilers, air brakes, interceptors) which failure will not cause the catastrophic situation because of its unproven safety ratings. At the same time, implementing of EHA in FCAS for deflecting primary flight surfaces looks more attractive but is still limited mainly because of its poor dynamic characteristics at low input signals which causes stability margins decrease: 15° of phase margins decrease and 2,5 dB of amplitude margin decrease.Originality/value Developed EHA with combined control of rod velocity is original technical solution, which combines high energy efficiency of traditional EHA and good control qualities at low input signals of traditional electrohydraulic actuators and thus can be potentially suitable for primary flight control deflecting. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ermakov S. A., Karev V. I., Konstantinov S. V., Obolensky Y. G., Selivanov A. M., Sukhorukov R. V. Fly-by-wire control systems and servo actuators design and development. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 161-171. This article considers the design principles of fly-by-wire systems of modern military aircraft and passenger airplane, principle design schemes of servoactuators with higher reliability, as well as application of heterogeneous redundancy in actuators systems of the critical control surfaces. It is shown that development of the modern aircraft control system dictates transition to the integrated digital complex control systems that ensure manual and automatic flight control with specified stability and controllability characteristics. The modern combat aircraft have unstable aerodynamic configuration, and the new passenger aircraft have low-stable configuration. That allows considerable enhance of the aircraft performance, however requires artificial improvement of the aircraft stability and development of new, more reliable automatic control systems. As an example, we consider a combat aircraft control system that performs functions of all piloting systems at the same time. The system design features a single control complex that combines both the aerodynamic surface control actuators and the control actuators of the exhaust nozzles of cruise engines with variable thrust vector. Also the article considers a redundant design of the aircraft power system, in which a failure of an engine, hydraulic system or power generation channel does not result in the control system failure. The combat aircraft design features electro-hydraulic servo actuators with the direct control valve. Airlines are interested in increase of power efficiency of servo actuators and decrease of aircraft maintenance costs, so they are keen to minimize the number of hydraulic systems. That leads to development of new servo actuator types — electrohydrostatic actuators. Such actuators allow to minimize the number of onboard centralized hydraulic systems on the aircraft. The actuators have following advantages: lower energy consumption, a higher efficiency factor, a possibility to boost the maximum pressure. The work provides a scheme of the new type servo actuator suggested by MAI specialists, in order to enhance dynamics in the low signal area. This is the servo actuator with combined control of the output link speed. On the aircraft that feature the power electric system along with one or two centralized hydraulic systems, it is expedient to use hybrid servo actuators with heterogeneous redundancy, where one channel is powered by the centralized hydraulic system and the other channel is powered by the electrical system. Such architecture of fly-by-wire control system allows additional enhance of failure safety of the aircraft servoactuators. This article considers the ways how to ensure flight control of a passenger aircraft even in case of failure of all regular electric power systems and/or electronic control units along with electric sensor, due to lightning strike, static electricity exposure, high radio radiation, radiation or other similar disturbance exposure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abrosimov V. K., Goncharenko V. I. Multiagent approach for aerospace attack scenarios description. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 171-181. The article is dedicated to potential enemy possibilities evaluation, when one develops aerospace defense system. It is considered the new hypothesis, which supposes an opportunity of data exchange between attacking flying vehicles. As the result the main core of controlled aerospace attack is distributed intellectual control system. It is suggested to use so called «multi agent approach» for described above event simulation. The set of agent states at each simulation level is represented as finite automaton, which has corresponding transfer functions. So, one receives the new opportunities to manage attacking vehicles maneuvers in order to create an additional complexity to aerospace defense system operation. Attacking flying vehicles are represented as interacting intellectual agents with Ai state vector, where Ai =<Bi, Gi, Si, Ni, UiEij, > ,i=1, n, here are: Bi is knowledge base of i-agent; Gi is set of i-agent targets; Si is set of i-agent strategies; Ni is set of i-agent intentions; Ui is set of i-agent obligations; E is multidimantional matrix, which defines «i» and «j» agents mutual interconnections, considering agents state, targets, intentions etc. The set of i-agent targets is defined by given agent set of tasks. The set of i-agent strategies defines the set of given agent program trajectories. The set of i-agent intentions is defined by set of targets, sel ected fr om the point of view given agent efficiency. The set of i-agent obligations is generated as the result of data exchange between different attacking flying vehicles. In particular, these obligations have to include the readiness to attack target, which can not be attacked by others agents. So, the main innovative performance of such aerospace attack is collective intellectual behavior of attacking flying vehicles. The basic concept of aerospace attack scenarios description is developed. The simulation of aerospace attack scenarios is provided by neural network utilization, because such approach gives an opportunity to implement simultaneous computation of various attacking vehicles trajectories. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chernomorskii A. I., Maximov V. N., Plekhanov V. E. Matrix form of motion model for uniaxial wheeled measuring module. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 182-188. The uniaxial wheeled module (UWM) presented in the paper is intended for automatization of measurements of runway detailed geometrical parameters (inclination angles, roughness, etc.). While measuring UMW should be balanced in such a way that allows its inverted pendulous platform to stay in horizontal plane when moving along a predetermined trajectory on the runway surface. This balancing is provided by accelerating UWM motion in the direction of platform inclination. The task of UWM trajectory motion guidance is being solved by forming required forward speed and track rate. There is an effective approach to such control problems called partial feedback linearization. Certain elements of the system state vector are chosen and non-linear transformation is carried out so that in the new (transformed) system with non-linear state feedback chosen elements would linearly depend on new control inputs. This approach assumes that dynamic motion model of the system under control is represented in special matrix form. In this paper authors present the derivation of the required motion model for the non-holonomic UWM with no wheel-surface friction taken into account. The method of Lagrange multipliers is used to derive the equations, while non-holonomic constraints which define subspace of valid velocities of the UWM are applied to get rid of unknown multipliers. Derived matrix-form model was tested by simulation together with partial feedback linearization control system, and it was shown that the accuracy of UWM balancing stabilization had been achieved of about 0.1 degree, what is quite enough to meet the measurement requirements. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharova N. G., Yurishcheva A. A., Karandin V. I., Rozhkov A. G., Kydralieva K. A. On the usage prospects of nanosorbents and fractionation methods in the space live support systems. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 189-197. This study was aimed to selection of beneficial methods for the systems of live support for long-term expeditions and subsequent rehabilitation, in particularly, for purification of biological liquids. A set of approaches was used for the lymph purification: centrifugation (g-factors made 1500, 1600, 11300, accordingly), micro- and ultrafiltration (0.22 micron and 67 kD, accordingly), and functionalized magnetite nanoparticles as biocompatible sorbents towards lymph components of sick patient. The latters were formulated using polymer-assisted method of synthesis, which proposed in situ chemical coprecipitation of chlorides of iron (II) and (III) valencies into the matrix of humic and pectin acids, accordingly. Some data on the nanoparticles formulated structure using scanning electronic microscopy and XRD analysis are given. The average size of nanoparticles calculated using Sherrer equation made ~16 nm for Fe3O4/HA and ~14 nm for Fe3O4/Pec. These results were agreed with SEM data. As the controlled sorption criteria, we have used the concentration of biochemical indicators for basic constant lymph ingredients, which determine cell, organ and general homeostasis at various diseases. Mechanical treatment using centrifugation and membrane filtration was shown sufficient decrease several times in the content of protein and lipid ingredients of lymph, in particularly, for alanineaminotransferase — twenty-fold, aspartateaminotransferase - three-fold, total cholesterol - eight-fold, creatinine -six-fold, total protein - four- fold, albumin - tenfold. But, glucose content was unvaried after treatment using indicated methods. Sorption study of the biocompatible functionalized magnetite nanoparticles towards lymph ingredients had demonstrated clearly beneficial potential of nanocomposites used towards all ingredients with exception of bilirubin. Decrease of lymph ingredients in comparison with initial sample made 50% and more. Our findings indicated that humic-based nanocomposite was found to be the more effective as a sorbent as compared with pectin-based one. Future experiments are planned under various conditions of liquid separation, extended sampling to confirm effectiveness of methods tested. In addition, screening of toxicity and stability of nanocomposite used, which is of special interest, will be our immediate goal. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhuk A. Z., Ilyukhin A. S., Okorokova N. S., Sevruk S. D., Farmakovskaya A. A. The research of the influence of the anode production technology for air-aluminium chemical current sources made of aluminium-indium alloys on their power and corrosive characteristics. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 198-208. The aim of the paper is the investigation of the effect of composition and production technology of anodes of air-aluminium electrochemical cells made of Al-In alloy on their energy, polarization and corrosion characteristics. We have examined the alloys produced by UIHT RAS and LLC «Scientific technical center «Metalcomposit» based on various technical processes restricted by specifications. The analysis of the alloys microstructures was made using the metallographic inverted microscope Axiovert 40 MAT. For various alloy samples the potential against standard silver-chloride reference electrode, discharge and corrosion current density were determined. The dependence of polarization and corrosion characteristics on the temperature and alkali concentration for the basic Al-In alloy containing 0,6 mass. % were also investigated. It was shown that the original aluminium type has no effect on the alloys energy characteristics and that the amount of indium introduced into the alloy have an effect on the corrosion characteristics only when the concentration is over 0,6 mass.%. Statistically the difference between the alloys with various production technologies is of no importance. The study of the effect of temperature and alkali concentration on the polarization characteristics (PC) of aluminium anodes made of the alloy of A95+ aluminium and 0,6 mass.% In in 4M and 8M solution of NaOH at a temperature of 298 K and 333 K has shown that the anode in the electrolyte with a higher concentration has more negative initial potential, but in current-carrying conditions becomes strongly polarized, moreover the PC inclination angle in 8M solution is bigger and at 298K the notable passivation of Al-In anode takes place at a current density of ~500А/м2. The research of the anode corrosion behaviour in 4M and 8M alkali solutions allows to conclude that despite a lower corrosion rate in a more concentrated electrolyte the use of the 8M alkali as electrolyte of the electrochemical cell is possible only with the addition of the inhibitors, because a negative difference effect takes place in the 8M solution. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ziatdinov R. A., Nabiyev R. I., Miura K. T. On some families of planar curves with monotonic curvature function, their aesthetic measures and applications in industrial design. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 209-218. The article deals with some of the families of planar curves with monotone curvature functions and their application in the geometric modeling and aesthetic design. The curves of this type include pseudospirals, aesthetic curves and superspirals, the curvature of which is given by the Gaussian hypergeometric function satisfying strict monotonicity under certain restrictions imposed on the parameters, as well as Class A Bezier curves, the function of curvature of which is monotone, and a detailed analysis of which has shown that with the degree of the polynomial increased, the curve converges to a logarithmic spiral. It is noted that controlling of the monotonicity of curvature function of Bezier curves and B-splines of n> 2 order requires a more in-depth analysis and development of appropriate algorithms. The descriptive part of this article provides an example of modeling the surface of the car body with a help of aesthetic splines. For the first time in the area of geometric modeling there is performed an aesthetic analysis and evaluation of the structure and plastic properties of curves with monotone curvature function from the standpoint of the laws of technical aesthetics. This analysis is based on the theoretical and methodological principles of aesthetic appraisal of form through art in the historical dynamics of its origin, formation and development in different cultures. The paper sets forth the idea of consciousness dependence on the psychological content of the formal signs of perceived reality and the possibility of their direct impact on human being to model the world-view and mould the certain personality type. In this regard, the objective character of the results represented in this paper and objectified in the formulas and visualizations is based on the integrative principle of «Dialectical Unity of Science and Art» as the two forms of social consciousness inseparably integrated into the system of public, spiritual and material production. In addition to the above, we make a conclusion that the union of science and art creates the conditions for formation of humanistic way of thinking of man supporting the unity of beauty and benefit of form in the spiritual and material space of his life as a leading ethical principle. Appraisal part of this paper includes a provision of design as an activity designed to unite the benefit and beauty in the harmonious form embodied in design rules and which for the individual are objective criteria for comfortable object perception of all its constituent features as a whole. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Smerchinskaya S. O., Yashina N. P. Aggregation of preferences in multi-criteria problems. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 219-225. Traditional algorithms of multicriterion search of optimal solutions use the numerical evaluation of alternatives based on various criteria so that reduce to difficulties in accurately estimating using the criteria such as usability, reliability etc. On the other hand the representation of all the criteria on the basis of the unified scale is a difficult problem. Here a method allowing making the best choice based on the aggregation of information about the preferences on the set of alternatives without specifying their quantitative estimates of the criteria is proposed. For all of the algorithms the software is developed. Let us consider a set of alternatives A = {a1, a2,..., an} and a set of criteria K = {K1, K2,...,Km} . For each criteria Ki (i = 1, m) an arbitrary binary relation characterizing the decision maker preferences is on the set of alternatives A defined. Let us denote these relations as p1, p2,..., pm. We need to construct a transitive and reflexive aggregation quasiorder; the choice of optimal solutions will be based on it. Let us define the preference relations by two ways.If the first one is used the preferences matrix Rt=|| rijt || of the order n where n is a number of alternatives having the elements defined as follows: if i ≠ j . Here riit=1 (i = 1,..., n) if pt is a reflexive relation, otherwise riit=0. The second approach consists in the representation of the graphs G1, G2,..., Gm corresponding to the relations p1, p2,..., pm by its adjacency matrix. The aggregate relation denoted by ^p must be non-contradictory and be in keeping with the preferences for each used criteria. The non-contradictory of the relation ^p consists in absence contradictory contours containing the alternatives being not equal; also this relation must be transitive. Minimum sum of distances between the aggregate relation of ñ and the relations p1, p2,...,pm allows taking into account the preferences for each criterion. Let us impose the next condition: where the distance between the relations is introduced by the following formula: To find the aggregated preference relation a weighted majority graph introduced in [3] is proposed. A weight defined below is assigned to each arc of this graph: The algorithm of constructing of the aggregate relation consists in two stages: the destruction of the contradictory contours in the majority graph by removing arcs having the smallest positive weight and construction of the desired quasiorder that can be found on the basis of the transitive closure of the relation p that contains no contradictory contours: identity relation e provides reflexivity. The proposed algorithm allows to introduce coefficients of importance k1, k2,...,km for each quality criterion K1, K2,...,Km. All algorithms have polynomial complexity. The proposed method can be used to create an aggregate preference relation for the problems of group choice. In this case the relations p1, p2,...,pm are the individual preferences of experts. Conclusions The proposed algorithm allows to construct a noncontradictory aggregated preference relation which is a quasiorder and takes maximum consideration of preferences for each criterion. Based on the aggregated preferences a choice the best alternatives can be made. It can be also noted that making of preferences based on criteria does not require evaluations of alternatives based on the scale of the criteria. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goykhburg D. M., Zemskov A. V., Tarlakovsky D. V. The one-dimensional transient perturbation of the bi-component elastic diffusion layer. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 226-237. The stress-strain state of a bicomponent layer is considered taking into account the structural variations caused by diffusion flows. The effect of diffusion to stress-strain state of materials is modeled by use of the locally equilibrium state model of elastic diffusion including the dynamic equations for elastic body and equations of mass transfer. The geometrically linear model of elasticity with diffusion is used. The bi-component homogeneous elastic layer (an alloy) with the surfaces parallel to the plane x1Ox2 of Cartesian coordinate system is considered. It is assumed that at the surfaces x3= 0,L the displacements, the heat transfer to the environment and diffusion flows are known. The mathematical model can be formulated with respect to Cartesian coordinates as follows: where t is time, xi are Cartesian coordinates, ui are displacements vectors components, L is the thickness of the layer, n(q) =n(q) ̶ n0(q) is the concentrations variation, n(q) is the concentration, n0(q) is the initial concentration of the q-th component, q in the composition of an two-component solid solution (medium), Cijkl are components of elastic constants tensor, αij(q) are the components of tensor defined by crystal structure type, Dij(q) are the components of self-diffusion tensor; g(q) is Darken thermodynamic constant, R is the universal gas constant, T0 is temperature. The coefficients Ʌ3333(q) are defined by the following formulae: It is assumed that at the surfaces of the layer the displacement and diffusion flows are set: where diffusion flows. The initial terms are assumed zero: The solution is based on the integral representation of the unknown functions. The right-hand sides of the equations are assumed as delta functions and the problem can be solved using Fourier expansions and Laplace integral transform in time domain. The received Laplace representations are rational functions depending on the transform parameter. Expanding of these functions into common fractions the inverse transforms are found and the fundamental solution of the problem is constructed. The final solution can be obtained as an integral convolution. The constant and exponentially decreasing diffusion flows at the surfaces are investigated as the examples. The numerical calculations have been made in the Maple 13 software. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ershov D. M. Optimization of resource allocation in strategic performance management process. Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 238-250. M. Hell, S. Vidacic and Z. Garaca (2009) developed the quantitative model of strategic performance (QMSP). They formulated linear optimization problem in which the criterion function was the total level of main strategic objectives accomplishment while constraints of the problem were dictated by the structure of cause-effect relationships between strategic objectives and limitations on resource amounts. One of the main issues concerning usage of QMSP in practice is a problem of assessment of cause-effect relationship coefficients. There are two approaches for solving it: the first one is coefficients evaluation with expert assessments (e.g. with method of pairwise comparisons proposed by T. Saaty) and the second one is the usage of statistical procedures. In our study we examined another approach to weight coefficients determination which involves interval estimation. According to our method, weight coefficients (all or some of them) are specified not precisely, but in the form of intervals. Its assumed that each coefficient belongs to some interval but it isnt known what value from the interval the coefficient will possess. Thereby the obtained problem belongs to the «problems with uncertainty» class and special criteria of optimality must be used to solve it. The first criterion which can be used is based upon extreme optimism (maximax criterion). It assumes an optimal allocation of resources under the assumption that «behavior» of uncertain coefficients will be the most favorable. So its usage gives an opportunity to evaluate the maximum potential of the developed strategy (considering that resource amounts are fixed). If decision maker isnt satisfied with it, then the strategy must be revised (or resource amounts for its realization must be increased). The second criterion which can be used is based upon extreme pessimism (maximin criterion). It assumes that «behavior» of weight coefficients will be the most unfavorable. Usage of this criterion thereby gives an opportunity to understand what result can guarantee strategy developed (considering that resource amounts are fixed). Algorithm for finding the maximax, the maximin and the set of compromise solutions involves formulation and solving mixed 0-1 linear programming problem. Usage of the method proposed is appeared to be particularly actual for aerospace enterprises because of high cost which company will have to pay in case if a wrong decision is made. The approach was applied within strategic planning process of a small-scale enterprise which was in United Aircraft Corporation and demonstrated its usefulness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Manturov D. V. Methodical approach to the assessment of efficiency of the russian federation state program realization «Development of the aviation industry for 2013-2025». Aerospace MAI Journal, 2013, vol. 20, no 2, pp. 251-260. Conservation status for Russia in world aviation power requires a change of strategic planning development of the aviation industry for the long term. In this context, the year 2013 is implemented by the Russian Federation State program «development of the aeronautical industry to 2013-2025 years.» The main objectives of the programme are: to upgrade civil aviation aircraft fleet to ensure transport availability throughout the country; maintaining research, industrial-technolo Maintaining the status of the world aviation power for Russia requires a change of strategic planning development of the aviation industry in a long term perspective. The Russian Federation State program «Development of the aeronautical industry in 2013-2025 years» was first implemented in 2013. The main objectives of the program are: to upgrade civil aviation aircraft fleet in order to ensure transport availability throughout the country; to maintain research, industrial-technological and human capacities, quality of domestic aviation at the level of its competitiveness on the world market; development of international cooperation and increased presence of domestic aviation organizations in aeronautical engineering and aviation services. The main objective of achieving these goals is to address the following organizational-economic tasks: to include the establishment of the world-class corporations in key segments of the aviation industry; establishment of science and technology stock that provides global leadership in aviation technology; promotion of domestic aircraft on domestic and foreign markets, the localization of production of aviation products of leading foreign companies and import substitution, get access to advanced foreign technologies. Effective realization of the State program is only possible when the economic mechanism of the program activities are generated, which will provide a concentration of financial resources on the most important areas of the aircraft, its engines, their parts, components and devices, avionics equipment, air traffic control systems. The efficiency of use of financial resources should be determined by the results of the systematic monitoring of specific indicators and indicators of program implementation as a whole as well as its subprograms. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Starostin K. I., Shustrov Y. M. Research on functioning of high-pressure water separation loop scheme during humid air processing. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 7-15. Purpose Environmental Control Systems (ECS) of most modern aircraft include loop schemes of high-pressure water separation (Fig. 1). Fig. 1. Loop scheme of high-pressure water separation: C,R are the heat exchangers (C is the condenser, R is the reheater); Т1, Т2 are the first and second cooling stages of multi-stage turbo-machine; MS-1, MS-2 are the moisture separators (dryer dehumidifiers); 08 sections of air parameters calculations The functioning of this loop during humid air processing is characterized by a number of specific features, which significantly influence the workability of separate units and the system as a whole. It is necessary to identify and analyze these features at the preliminary stage of ECS design. Thus the purpose of this paper is to compose the appropriate mathematical model of water separation loop scheme and create a program on its basis. Final goal is to perform calculations (numerical studies) to identify the specific features of system functioning during humid air processing for various combinations of initial data. Design/methodology/approach Mathematical model of the considered system includes the general equation of humid air enthalpy and a system of equations for calculation of air parameters at each unit outlet in the loop scheme duct. Enthalpy equation was solved with the usage of modified chord method developed with taking into account the specific features of the enthalpy function, which are connected with the physics of liquid evaporation and freezing. The numerical method for the equation system solution consists in successive iterations of enthalpy values in the loop scheme cross-sections towards their final values. This algorithm is similar to a checking calculation, which allows it to obtain the results on the particular modes of loop scheme functioning and model the transition modes. If it is taken into account that each of the iterations takes some time, it is possible to say that the calculation actually simulates the functioning of the system from the starting mode to the final. A method of evaluation of workability of separate system units, which includes tests and criteria for each unit, was developed and applied to analyze system functioning during numerical experiment. A series of numerical experiments was carried out with the help of the developed program. In this series the parameters of one or several units were changed with certain steps. Findings The distributions of air temperature along the duct for various initial data combinations were obtained. Comparative analysis of program calculation results with the results from similar programs and full-scale tests has shown that the model is highly reliable and the air temperature values along the duct differ by no more than 5 degrees from the reference results. It was also discovered that certain combination of unit characteristics leads to unstable modes of system operation. Failures due to condenser and reheater icing are the most critical for the ECS system with three-stage cooling turbo-machine (one-stage turbine). Usage of four-stage cooling turbo-machine (two-stage turbine) within the loop scheme allows to significantly reduce the probability of icing of the heat exchanger components. However, it also creates additional problems with moisture in the output section of the system. The research has shown that workability of the systems with high-pressure water separation scheme can only be achieved via precise and proper combination of unit characteristics and air parameters in the inlet section. Unsteady operating modes and icing possibility significantly affect workability and efficiency of modern aircraft ECS. This results in more stiff requirements to the ECS subsystem of preliminary thermal air processing and subsystem of automatic adjustment of ECS operational parameters. Research limitations/implications An assumption was made that air-flow rate does not change within the allocated ECS section and system functioning mode is considered to be stationary. Originality/value Application of the proposed chord method reduces the required iteration number by 1.5...2 times compared to a «normal» chord method and provides two-sided convergence. This method also helps to absolutely exclude the emergence of iterates out of the allocated interval bounds, which in turn increases the convergence robustness. Application of proposed numerical methods for modeling of aviation ECS functioning at the early design stage can undoubtedly be useful and serve a practical purpose for organizations connected with manufacturing and operation of these systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Soloshenko V. N., Popov Y. I. Conceptual design of composite wing box structures for a medium-range passenger airplane. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 16-30. Purpose To give a review of the main requirements, which should be taken into the account during the design of a composite wing of a trunk-route airplane. To analyze the main concepts and structural layouts of composite wing box structures and wing root joints (wing box splice joints) of the new passenger airplanes. To determine the particular features of the allowable stress selection for the design of composite airframe structure of a trunk-route airplane. The object of research is a wing of a passenger aircraft with take-off weight m0= 65000 kg and the following geometry parameters: aspect ratio λ = 11,5, 1/4 chord sweep angle Χ =25° and wingspan of 35 m. Design/methodology/approach Several basic design concepts and structural layouts of composite wing box and wing root splice joints of the new passenger trunk-route airplanes are shown and analyzed in the paper: multi-rib structure with stringer stiffened skin panels, multi-spar structure with flat skin panels without stringers, honeycomb sandwich panel structure. Advantages and disadvantages of each design and structural layout are emphasized and analyzed. The paper also shows several variants of wing box root splice joints for different composite wing designs and discusses the problems associated with each splice design. Findings It is shown that the majority of airframe manufactures use traditional structural layouts for composite wings that were used for metal wing design for many decades. Such decision is based on a rational desire to reduce the technical risk and widen the field of application of the well-known procedures of wing certification onto the cases when the wing is made of composite materials. As shown in the paper the allowable stress for wing design depends on a multitude of factors besides the composite materials characteristics, among those are: mechanical and thermal loading, design of irregular structure zones, certification requirements and damage scenarios during manufacturing and operation. All of these factors must be taken into account at all design stages. Also all of these factors significantly decrease the advantage of utilization of composite materials over metal down to the level when it becomes rather small. The following can be proposed to increase the potential weight reduction effect: to increase the impact resistance of composite structures by using matrix systems with higher interlaminar fracture toughness; to introduce the fiberglass crack stoppers into the wing design. Research limitations/implications The present study provides a review of the existing designs, identifies the potential problems of their application to the research case and offers several solutions to these problems, which require further elaboration. Originality/value The design of composite structures for trunk-route passenger airplanes is a highly important and popular topic of today. However, the available information is still somewhat limited due to the small number of actual projects that would fully utilize the appropriate technology. This paper tries to generalize and extend the available knowledge based both on the available data about actually implemented projects as well as the theoretical systematic approach to extending this data and applying it to a given case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Govorkov A. S. Method of quantitative assessment of the airframe element manufacturability. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 31-37. Purpose Nowadays element design is carried out with the help of CAD/CAM/CAE/PDM systems. Thus it is rational to estimate the manufacturability of element structure at early stages of product launch during element design and manufacturing. The goal of this paper is to provide a method for such evaluation. The paper considers a method of manufacturability calculation and estimation, which allows formalizing the process of airframe element manufacturability evaluation and altering characteristics and parameters of individual indicators. Design/methodology/approach While refining the airframe element design with the purpose of increasing the airframe manufacturability, one must take into account the manufacturing type and specific features of the manufacturer (manufacturing plant) so that structure of individual elements could be produced with taking the aforementioned factors into account. The paper proposes a method of quantitative estimation of airframe element structure manufacturability based on interaction of individual indicators with taking into account their weight-coefficients. Also an algorithm for manufacturability control of the element based on its 3D-model is suggested. Final assessment of industrial manufacturability is carried out according to single individual indicators by comparing the variants of the proposed element with analogues, which are already manufactured at the considered plant. The aggregated indicator value is determined under the conditions of an extremely unfavorable combination of individual indicators based on expert estimates. The quantitative assessment of element manufacturability during its design is carried out with the help of an aggregated indicator: where ki is the value of individual element manufacturability indicator i; ϕi is the weight-coefficient of individual element manufacturability indicator i; n is the number of adopted indicators, which is defined by the expert and must be no less than 5. Weight-coefficients of the manufacturability indicators are determined by experts. Part of the indicators can be used again to evaluate other airframe elements while their weight-coefficients should be reidentified based on new expert estimates. Findings It is difficult and often impossible to fully estimate manufacturability level at early stages of manufacturing process design because of insufficient information. To ensure the structure manufacturability it is possible to make a qualitative assessment via manufacturability properties and carry out the quantified evaluation using individual indicators. The proposed method was tested on the example of structure design of sheet pressed airframe elements. It was discovered that this method does reflect the real conditions of structure design and manufacturing processes. Research limitations/implications The proposed method is based on expert estimations. Thus additional work is required for selecting the appropriate groups of experts to make these estimations less influenced by subjectivity of particular personalities. Originality/value Proposed methodology of refining the element structure manufacturability can be successfully applied in practice for calculation of manufacturability and estimation of the quality of the new developed airframe elements. This is especially important since it might be hard and/or impossible to carry out the manufacturability estimation for such elements according to the main indicators of the standards at the early stages of pre-production planning due to the lack of information, while the ability to carry out the estimation according to additional indicators is limited since such estimation would only reflect the structural design aspect. Technologies and methods of manufacturing design change over time. The proposed system of manufacturability analysis aspires to «isolate» the designer from such changes while still taking them into account during the creation of the model of the element manufacturing process. Application of structure manufacturability analysis provides for adaptation of the method to the specific manufacturing by accumulating knowledge about its technological basis. This ensures adaptability of the method as a whole and takes into account general and particular characteristic features of manufacturing. The recognition method works with structure models, which are based on solid-body primitives, thus ensuring the invariability of the manufacturability analysis method towards the way the model was built. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bezruchko K. V., Davidov A. O., Katorgina J. G., Logvin V. M., Stolyarov J. A., Kharchenko A. A., Shirinsky S. V. Development and testing of mathematical model for behaviors prediction of power plant electrochemical batteries of space-rocket objects. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 38-49. Purpose The main aim of the work is to develop a mathematical model of electrochemical battery. This model makes possible to predict the value of the main parameters and features of the batteries during the longperiod of operation with degradation processes in them. Development/methodology/approach The methods of systems engineering and fundamental equations of thermodynamics and electrochemistry were used in the process of mathematical model development. These methods are specified with the help of experimental data. The output vector of the mathematical model for electrochemical battery contains residual capacity and open-circuit voltage. The operation time is used as the initial parameter. The equation for open-circuit voltage calculation is based on Nernst equation. The residual capacity equation was obtained by means of Erofeev equation modification. Findings Testing of mathematical model was carried out at Nickel-Cadmium cells НК-125, НКГ-160 and 3НК-125. By means of experiment the current state of cells and battery were defined. The coefficients of the mathematical model were calculated; continuous prediction of open-circuit voltage and residual capacity of cells and battery for a long operation period have been carried out. The maximum meaning of average absolute deviation of capacity, which have been obtained experimentally and calculated by means of the model, is less than 0.86 A·h. The maximum of average error is less than 9,7%. The absolute error of the capacity after 20 years of operating is less than 1,1 A·h, and approximation error after 20 years of operating is less than 12%. The confidence interval of relevant parameter after 30 years of operating with the probability of 0,95 is 18A·h for capacity and 0,03 V for voltage. Research limitations/resume The present research is the start for the further investigations in the field of electrochemical batteries life-time prolongation of rocket-space objects power plants. Originality/value The mentioned researches have made possible to predict the value of the main parameters and electrochemical batteries characteristics both for long-operating power plants of space-rocket hardware and other power plants with electrochemical batteries. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panchukov A. A. Integral criteria of injection accuracy. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 50-56. The injection accuracy is one of the main characteristics defining the perfection and competitiveness of the space-mission vehicle (SMV). The data of the modern SMV injection accuracy is published in the International User Manual, which is devoted to launch vehicles [1], for 24 versions of thebase target orbits, in which amount the circular or close-to-circular orbit is included. The list of controlled parameters is specified by each developer of SMV in the useful for him form and, as a rule, with a reference to an orbit inclination, which complicates a comparison and tradeoff analysis of the injection accuracy values acceptable for customers and assured by developers.
The paper describes and analyzes universal criteria of the injection accuracy for close-to-circular orbits. The requirements for spacecraft injection accuracy in the orbit plane are set by one or another combination of inequalities given below: Here, are deviations of radii of the perigee rπ , the apogee rα; , radius rв at the insertion point, of T period; index * marks their maximum allowable absolute values. During the requirements development for the near-circular orbits injection accuracy of the Energia launch vehicle a universal and capacious criterion was proposed: (1)
for any argument of latitude u ∈ (0-360°), i.e. the altitude of the real orbit has to deviate fr om the design one at any point of a circuit by a value not exceeding Δr*.
Let ∆r0, ∆νn0, ∆νr0 be distance, transversal and radial components of the velocity vector at some argument of latitude u0. It is shown that (1) defines a convex three-dimensional region in the space of deviations ∆r0, ∆νn0, ∆νr0. If these deviations at any point of a circuit are so that their values belong to the indicated three-dimensional region, the radial deviation throughout the motion process will not exceed the set value ∆r*. For near-circular orbits condition (1) is equivalent to the unique set of conditions set by it, namely
and it can be recommended as a universal criterion of the injection accuracy.
The angular position of the injection orbit plane inspace is usually set by orbital inclination i and longitude of the ascending node Ω . Allowable errors of the orbit plane position are set by limiting deviations of ∆i and ∆Ω of the mentioned parameters, respectively, fr om the design ones. It is known that the same errors of the injection orbit plane shaping (specifically a targeting error) lead to the different deviations ∆i, ∆Ω depending on the inclination and latitude of the start point. Therefore, to assess the injection accuracy in lateral direction, it is also advisable to use the integral criterion
|z(u)| ≤ z* (2)
for any argument of latitude u ∈ (0-360°), wh ere z is a deviation along the normal to the orbit plane. The terms of (1) and (2) lim it the tube of disturbed trajectories by a torus. In this case, the areas of allowable deviations of kinematic parameters are convex set, which makes possible the geometrical visual comparison of these parameters with characteristics of scattering correlation matrices (ellipsoids of equal probabilities).
Integral criteria |∆r(u)| ≤ ∆r* , |z(u)|≤ z* are connected with deviations of kinematic parameters at any point of a circuit and can be useful during the comparative characteristics analysis of the insertion accuracies for different SMV. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Magerramova L. A. Increasing resource ofthe aviation gas turbine blades by calculation methods. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 58-70. The growing competitive requirements to improve parameters of gas turbine engines (GTE) lead to more accurate calculations, the use of new materials and designs. Besides the possibilities of mathematical modeling for design and strength calculations have considerably increased to take into account the particular load and behavior of materials. The turbine wheels are among the main components of the gas turbine engine that largely determine engine basic parameters. The turbine parts operate at high temperatures at stationary and transient regimes under cyclic loading during aircraft evolutions. In addition, the turbine blades are exposed to aggressive environment, high temperature gradients, centrifugal and gas loads. The calculation methods of turbine blade life time increase are based on:
High temperature single crystal nickel alloys widely used in aviation turbine blades have anisotropic properties. The commercial computer complexes used in the world practice for complicated calculations by 3-dimensional element models allow to take into consideration only elastic properties of cube symmetry of single crystal blade. There are no material models that have cube symmetry properties of plasticity and creep in these complexes. Based on the conducted investigations a model of material behavior has been selected and a method of SSS calculations for single crystal turbine blades has been suggested. The investigations of crystallographic orientation influence on SSS and static strength of single crystal blades for high temperature gas turbines have been conducted to determine the optimal location of the single crystal in the blades. It is not possible to calculate turbine blade strength without taking into consideration stress relaxation during long-term operation at stationary regimes. It is necessary to know characteristics of alloy creep in the wide range of operating temperatures and time. However the volume of experimental data on creep resistance is limited. There is a set of equations to describe creep strain in the commercial computer complexes with 3-dementional element modeling. The algorithm has been developed to establish coefficients of the selected creep equation and (or) creep strain rate according to available experimental data. The investigations on stress relaxation using different methods have been conducted. The method of establishing blade allowable life time has been suggested. It is expedient to conduct calculations of SSS using several flight cycles including transient regimes. The stress and strain rages can exceed the corresponding parameters of a zero-to-maximal cycle during loading, operation at different regimes, deceleration and shut-down. One of the important trends of ensuring blade life time for advanced high temperature aviation gas turbine is the application of effective durable coatings. Specific problems connected with the ensuring of strength and durability for blades and coatings at thermal and mechanical loads. The examples of numerical analysis of constructions are given, the actions on improvements that ensure durability are shown. The recommendations on turbine blade life time designing are given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ageenko Y. I., Pegin I. V., Shalamov E. A., Ilyin R. V. Experimental study of the possibilities of increasing the effectiveness the liquid rocket engine thrusters 400 newtons with deflector centrifugal mixing scheme. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 71-78. The purpose of the experimentally-scientific work is possibility increase of efficiency Liquid rocket thruster 400 newtons by optimization of a supply and mixture of components of fuel on a wall of combustor. In Isaev Chemical Machinery Design Bureau four liquid rocket thruster (25...200 N) with deflector centrifugal liquid phase mixing scheme of propellant components on combustor are developed. All this liquid rocket thruster provide a high specific impulse, working capacity at the large resources and the high reliability caused by a considerable stock on temperature of engine elements. Application of deflector centrifugal mixing scheme for liquid rocket thruster, for example 400 N, has been limited now, as in the mixing element one centrifugal injector of fuel and set of jet injector of an oxidizer that is required to minimization of volumes of bunging channels and support of the maximum uniformity of distribution of oxidizer film and fuel on a surface of the combustor is used only. For increase of efficiency by again developed liquid rocket thruster with deflector centrifugal mixing scheme work by definition of the optimum form and reduction volumes of bringing fuel channels of a mixing head has been spent. The bringing collector in the area giving of an oxidizer with a direct supply of an oxidizer to each jet injector, providing the maximum uniformity of a stream has been with that end in view developed at an input in jet injectors. Also the form of high-precision apertures of jet injector of the oxidizer has been developed for support of optimum distribution oxidizer film on deflector and surfaces of the combustor, providing minimum «blooming» effect of streams profile and also the new method of three dimensional electro erosive manufacturing profile micro apertures is applied. The received results have been experimentally tested and confirmed in the engine that has allowed to received comprehensible speed, high power characteristics and steady work of the engine in wide changes range pressure of components of fuel on its inputs. In the given work tests results of experimental engine 400 N with achievement of a specific impulse to 3030 m\s are represented also. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishin Y. A., Bakulin V. N., Zenkin V. A. Numerical modeling of inlet ports testing of two-strokes engines. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 79-87. Two-stroke piston engine is the most economical for usage in structure of power plant of pilotless vehicle of different purpose. For the vehicles of light class two-stroke engines with simplified system of interchange of gases through intake and exhaust ports are used. Gas-dynamic characteristics of intake (scavenging) ports are the main parameters for calculating and experimental optimization of working process of the engine and, as a consequence for definition and getting the power and other required measures of the engine. Under gas-dynamic characteristics, at the first place are understood the dependence of discharge coefficient and spatial field of velocity of incoming air charge into cylinder from opening stroke, inclinations of walls and structural implementation of intake part of the port. In the present work the numerical investigations of the above mentioned characteristics were made with the help of created in MSTU by Bauman software complex of calculating gas-dynamics NFS based on the new implicit version of the method of large particles, providing second degree of accuracy by time and space. At that the representation of inclined secants inside orthogonal regular calculating grid is being used. Version provides higher accuracy and reduces the time of calculation by major increasing the grid number of Courant. Also different physical models of gases are implemented, including polytropic and isothermal. Application of different models of viscosity is provided. As the result of calculations, the necessary dependences for discharge coefficient were received, which matches well with given experiments. The influence of degree of port opening and configuration of intake receiver and performance of intake part of the intake port to discharge coefficient examined. Fields of velocity, defining the peculiarities of entering of charge into cylinder of the engine at scavenging- through the ports are received and analysed. Results of work will be used at calculating-experimental investigations and finishing the engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kudimov N. F., Panasenko A. V., Safronov A. V., Tretiyakova O. N. Calculation of turbulent supersonic jet on modes specific to launch rockets. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 88-94. The primary goal of the current research was to provide numerical simulation for the analysis turbulent supersonic jets such as isobaric cold, non-isobaric cold and hot jets specific to launch rockets. Also numerical simulation is used to investigate supersonic turbulent hot jet impinging on the wall at angle to the jet centerline axis. In calculating the jet stream at the start of the propulsion and launch rocket the is very important accurate simulation of shock, rarefaction areas, viscous-inviscid interaction in turbulent mixing layer. Numerical simulation based on the three-dimentional Reynolds equations with various turbulent model (Spalart-Allmaras and SST). Spalart-Allmaras model is a one equation model which solves a transport equation for a viscosity-like variable. The SST k- ω turbulence model is a two-equation eddy-viscosity model which has become very popular. The use of a k- ω formulation in the inner parts of the boundary layer makes the model directly usable all the way down to the wall through the viscous sub-layer, hence the SST k- ù model can be used as a Low-Re turbulence model without any extra damping functions. The SST formulation also switches to a k- ω behaviour in the free-stream and thereby avoids the common k- ω problem that the model is too sensitive to the inlet free-stream turbulence properties. For each of the condition studied in this investigation, it was observed that the velocity and pressure along axis provided the satisfactory prediction to the experimental data. Experimental and numerical wall surface pressure distribution satisfactory agreed with each other. Conclusion
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Leontiev M. K., Snetkova E. I., Degtiarev S. A. Dynamics of unbalanced rotor mounted on roller bearings. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 95-105. Object and purpose of the study The dynamic characteristics of an unbalanced rotor system with roller radial bearing in the nonlinear statement were investigated. The algorithm to simulate the radial roller bearing in tasks of rotor dynamics was developed. It was programmed as a module in the software system Dynamics R4 intended for modeling and analysis rotor dynamics of turbomachinery. Methodology The rotor system consisting of the point «case» with mount, the point «rotor» and the nonlinear bearing was investigated. Mathematical model of the nonlinear bearing is based on the theory of Hertz and considers bearing clearance, the number and inertia of rolling elements, the weight of the rotor and unbalanced force. Findings During start up from 0 to 30000 rpm and following shut down to zero rpm several transition stages can be identified: the area of chaotic motion in the initial phase of the motion (rotor is on the ring of bearing), the area at which the rotor becomes a stable near-circular motion under the action of the unbalance force, the area on which there is a transition through resonance and the subsequent behavior of the rotor is accompanied by slight unbalance forced oscillations and the intense chaotic traffic with following passing in parametric oscillations. Study the chaotic motions of the rotor noted that for the normal operation of the bearing should be a balance between the forces acting on the bearing (weight, unbalanced forces, the forces of inertia) and the clearance in the bearing. Originality/value The results show the need for the preliminary study of any dynamic rotor systems in nonlinear statement in order to make a correct choice of bearing type, size, clearance, minimum rotor unbalance ets. That is, the parameters determining the stable and reliable operation of the rotor system and eventually, bearings durability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grigoriev V. A., Kalabuhov D. S., Radko V. M. Investigation of the regime and geometric parameters influence on single-stage ultralow power axial turbine volume and mass. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 106-113. Object and purpose of the study A promising way is to increase the efficiency of the turbine drives the optimization of geometrical and operational parameters of ultralow power turbines (ULPT) by solving the optimization problem. Optimization problem have to be solved in multi-criteria setting, with the turbine drive mass as one of the most important criteria for evaluating the turbine drive effectiveness. In the open scientific literature any information on the mathematical model of ULPT mass is absent. In this paper, as the object of study a single-stage axial ultralow power turbine (AULPT) is considered. Methodology The authors of this article in their work showed the need to build models of the mass as a function of the main influencing factors non-dimensional geometrical and operational parameters of ULPT. The proposed mathematical mass model is based on the preliminary determination of the turbine volume. In this case, for the turbine model the schematic image of the turbine, which is an assumption by numerical and analytical methods is taken. The model is only partially analytical, because the expressions for the determination of areas blade profile data are compiled by computer simulation. Findings Mathematical model of the mass was used in the analysis of the influence of geometrical and operational Scheme of single-stage AULPT parameters on the axial turbine mass, the details of which are made of steel D-16T with density = 2800 kg/m3. The analysis revealed that the most significant effect on the mass factors are the scale factor the relative diameter ̄DM= Dm/ 0,05 [m] , aspect ratio of nozzle vanes to the average diameter hN/Dm and elongation of the blade (s/h)N. For example, increases of ̄DM with the value of 0.6 to 2 can lead to an increase in mass of 15, while the increase of hN/Dm from 0.01 to 0.05 increases the mass by about 3 times. Specified mathematical models of volume and mass are not very convenient to analyze the simultaneously influence of several turbine parameters and for further optimization of these parameters according to the criteria of volume and mass. Therefore, by statistical analysis of volume of 100 experiments specially developed experiment plan the regression expressions in the form of quadratic polynomials were obtained. Statistically significant coefficients of the model were only factors hN/Dm , (s/h)N , ̄DM and the degree of partiality ε. Within the range of variation of other factors mass varies by no more than 5%, which allows the designer to be more free to choose the parameters of blade rims. Originality/value The developed mathematical model of mass can be used for solving the multi-criteria optimization of AULPT parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Simonov E. L. Verification of a technique of non-contact blade vibration stress measurement by discrete-phase method. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 114-123. This paper deals with technique verification of turbomachine blade tip-timing (BTT) measurement by discrete-phase method. The article touches upon the issue of dynamic loading as one of the most dangerous forces exerted on gas turbine engine (GTE) wheel blades. Alongside with a conventional method of GTE rotor blade vibration stress measurement using slip-ring devices the technique of non-contact blade vibration measurement (discrete-phase method) is intensively developing. Discrete-phase method (DPM) enables researchers to receive full strain distribution pattern simultaneously on all wheel blades, to measure blade vibrations of a two-shaft GTE. DPM is applied by experts in gas-turbine machines in Russia («CIAM», «LMZ»), Germany («MTU»), Great Britain («Rolls-Royce»), France («Fogalenanotech», «Snecma»), USA («General Electric») and others. The purpose of this paper is to implement experimental computation optimization of BTT with CAE systems technology application. The above method includes measurement and comparison of the actual time of rotor passing by sensor with expected time (time of an absolutely rigid blade passing). In certain time frames at known frequency of rotor rotation, the deviation of circumferential blade cross-section and its turn by centrifugal and gas forces relative to equilibrium position is determined. If the blade vibrates with frequency not aliquot to rotation frequency, time frames at each turn will be different. Registering them by DPM devices it is possible to determine blade vibration amplitude. The test bench for BTT technique optimization has been designed and manufactured in OJSC «Aviadvigatel» (Perm). Fifth-stage rotor blade vibration stress measurement of high pressure compressor of GTE PS-90A is carried out by BTT at the same time with strain-gauge measurement of rotor compressor on the test bench of OJSC «Aviadvigtel». To define blade vibration parameters by DPM devices the turbomachine preparation is performed particularly in the circumferential direction some impulse (capacitive) sensors having no mechanical contact with turbomachine rotating parts are located on the compressor stator. Capacitive sensors type HPC-30-62-200-04 of SPE «Mera» (Mytischi) production are placed on the test bench. For identification of a blade and initial rotor position parallel to test bench rotation axis the induction sensor DCHV-2500 used to define phase and produsing one impulse per a turn is installed. Methodology. The computational analysis of rotor blades stress-strain behavior (SSB). To convert circumferential cross-section movement into blade vibration stress the data of blade movement are required. For this purpose we will perform dynamic stress distribution calculation for every vibration mode investigated. For mathematical model verification of DPM the relation of blade vibration stress in the strain-gauge installation sites to circumferential blade cross-section displacement has been defined. Circumferential cross-section movement in the capacitive sensors installation sites above the blade and the movement relationship with vibration sites have been calculated by finite-elements method. In order to build a mathematical model of BTT measurement by DP technique, the blade vibration stress relation to circumferential cross-section movement has been defined by an analytical analysis as well as experimentally. Natural frequencies obtained by an experiment appeared to be lower than estimated ones, which can be explained by more rigid boundary conditions, taken into consideration (fixing all contact surfaces units in all directions). Conclusions The following convergence of test results with estimation has been received: natural frequency lapse does not exceed 1,6 %, vibrations amplitude lapse 7,3%. The comparative results analysis of rotor blades vibration measurement received by strain-gauge and BTT measurement is carried out. The received lapse ranged from 8,7 % to 19,0 %, which is acceptable at the present stage of researche. At the moment in OJSC «Aviadvigatel» conducted to decrease the lapse to the levels which do not exceed 10 %. Calculation of rotor blades vibration stress is executed at vibrations on the lowest vibration modes (for example on the 5-th stage of GTE high pressure compressor PS-90A). SSB calculation and modal characteristics of high pressure compressor rotor blades is carried out in finite elements analysis package ANSYS. The mathematical model connecting the dynamic SSB with blade circumferential cross-section movement is built. Further research trend involves implantation algorithm formation of natural vibration modes definition and operational vibrations stress in tempo of tests. Furthermore geometry dispersion of the profile part and the lock consideration as well as natural blade frequency is planned to include in the computation. The received results at the moment are used by investigation of the perspective fifth generation engine on the benches of OJSC «Aviadvigatel». | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Potapov S. D., Perepelitsa D. D. Research of characteristics of cyclic growth rate of cracks in materials of the critical parts of aviation gas-turbine engines. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 124-139. The research aimed to establish the possibility of using the results of sample tests for evaluation of fracture in real detail. The effect on the rate of crack growth in standard samples of different factors: temperature, sample thickness, loading frequency, the asymmetry of loading cycle, the influence of plane stress on the sides of the specimen, crack growth under high stress intensity factor, and so on are determined. The stability of the geometry of the crack front in the standard samples with the development of cracks are investigated. Stability boundaries of the site and the coefficients of Paris for the test results of standard samples using the method developed by the authors are determined. The studies were conducted for aircraft materials: nickel and titanium alloys and steels at the operating temperature range. Based on the results the linear relationship between the coefficients of the equation of Paris and the focal point of presence on the kinetic diagram for all the materials are established. The presence of a focal point confirms the fractographic studies fracture surfaces of samples. The presence of a focal point allows you to set: one value of the exponent of the Paris equation there, and only one, the coefficient of the equation Paris, average coefficients Paris should ensure passage of the averaged characteristics of crack growth rate in the focal point, the average values of the coefficients of Paris can be determined using linear relationship between the coefficients of the equation Paris. For nickel alloys a decreasing dependence of the degree of the equation Paris on temperature was received. For titanium alloys, this dependence is absent. Developed a special model allows us to investigate the development of semi-elliptical surface cracks. Comparative tests of cross-cutting and surface (semi-elliptical) cracks in standard and special samples were made. These results suggest the influence of fracture type (pass-through or semi-elliptical surface) on the characteristics of the crack growth rate. The results suggest the need to study the development of cracks in the evaluation of different types of longevity of critical aircraft engine parts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Davydov A. V., Degtiarev S. A., Kutakov M. N., Leontiev M. K. Dynamics of electric machines rotors with unbalanced magnetic pull. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 140-151. Object and purpose of the study Object of the study is Unbalanced Magnetic Pull (UMP) which arises in electric motors and generators and must be taken into account in rotor dynamics tasks. Review of existing methods of UMP determination noted its nonlinear nature. The algorithm to solve the task of rotor dynamics behavior with UMP in nonlinear transient analysis was created. Hydraulic turbine generator with UMP was analyzed. Methodology UMP value in electric machines depends on the eccentricity of rotor, the geometric size of the machine, the value of magnetic field in the air gap, the magnetic properties of rotor material, presence of the stator winding parallel turns. In nonlinear definition the matrix equation describing the nonlinear dynamic model of the rotor system is given by: [M]{ü}+ [C]{ù}+ [K]{u} {F(t)}+{R}, where [M] inertial matrix; [C] damping matrix; [K] stiffness matrix; {ü} {ù} {u} respectively columns of vibration acceleration, velocity and displacement; {F(t)} dynamic loading of any types internal or external; {R} the nonlinear reaction, taking into account a magnetic force between rotor and stator. The equation can be integrated in accordance with the scheme shown in figure. Findings It is shown that the UMP has a major influence on the rotors vibrations of electric machines. It reduces the critical speed, changes the position of resonances and vibration amplitudes. The main advantage provided by the method and developed algorithm is its relative simplicity and minimum of input data. Application UMP model to the studied rotor showed that the significant difference between linear and nonlinear statements appears when the air gap is more than 40%. Originality/value The presented method and the algorithm was implemented in the software system Dynamics R4 which allows you to carry out quickly and accurately the design and analysis dynamical structures of electrical machines in nonlinear statement with the UMP, as well as other nonlinear properties. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlova N. V., Zagrebin D. A., Adaskin A. V., Sergeychik V. V. Multichannel twenty-four hour diagnostic system for civil aviation flight personnel cardio-vascular pathology examination. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 152-162. In this paper authors present the results of development of Multiholt a new portable twenty-four hour recording diagnostic system for flight and control staff examination in process of preflight preparation, certification, and rehabilitation. Authors present technical characteristics of hardware and functional capabilities of software. Multiholt can simultaneously measure and record parameters of breathing activity, heart functioning, pulse oximetry and blood pressure that provides data for cardiovascular system dysfunctions analysis. Also shown how the usage of multidimensional diagnosis helps to increase performance and quality of examination of flight staff. Database of multichannel twenty-four hour recording results has unique characteristics and allows storing, viewing, analyzing, postprocessing and printing recorded signals. The main reasons to use the Multiholt in medical practice:
Multiholt is based on modern microprocessors with cutting-edge programming technologies that provide unique operational characteristics for high-quality cardiovascular diagnosis of flight personnel on all stages of medical examination. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitin D. P., Gerko S. A. Using delta phase measurements in the global navigation satellite systems receivers for machine control applications. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 163-174. Purpose This paper provides a reader with an overview of modern methods for improving the characteristics of navigation solutions for some machine control tasks by using the pseudo-phase measurements in the global navigation satellite systems (GNSS). Design/methodology/approach The development of the algorithms for navigation data processing is based on the filtering of primary estimated receiver position. It allows one to perform machine control tasks when an unexpected change of GNSS receiver operating mode takes place. Performing a relative coordinate determination for a moving object one has to take into account unexpected difficult conditions, e.g. a small number of visible satellites. The proposed approach to overcome such difficulties consists in the processing of delta phase measurements formed at different time intervals. Findings The processing of delta pseudo-phase measurements showed the relevance of phase measurements for machine and aircraft control tasks by means of GNSS. Proposed methods used in the combined filtering and initial position estimates of a navigation receiver will processed in one filter with delta pseudo-phase measurements. As a result this filtering procedure leads to the improvement of the positioning accuracy (in the RMS sense) in the case of an accidental change of the operating mode of a navigation receiver. The discussed algorithm for evaluation of the relative coordinates of moving objects can increase the probability of the correct ambiguity resolution of pseudo-phase measurements in 3-5 times in comparison with the known algorithm RTK when a receiver has 4-6 satellites in view. This will increase the reliability of the estimates of the coordinates. Thus, the safety level of aircraft movement could be increased by usage of systems based on the GNSS or integration with GNSS systems. Originality/value The application of advanced methods for improving the performance of navigation solutions can significantly increase the user value of navigation equipment. The developed methods is planned to expand the functionality of navigation receivers in industry, e.g., in the controlling of construction, agricultural, mining and manufacturing equipment, and in both automatic and semi-automatic aircraft control. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilin A. N., Karandin V. I., Rabinsky L. N., Rozhkov A. G. On the prospect of using of sorbents based on carbon nanotubes in life support and rehabilitation systems. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 175-182. Purpose Carbon nanotubes (CNTs) sorption properties and prospects for their use as biocompatible sorbents for life support and rehabilitation systems are investigated. Design/methodology/approach CNTs has been synthesized using technologies of chemical vapor deposition method on the catalyst systems of Fe/Al2O3 and Co/Al2O3. The sorption efficiency of sorbents is demonstrated in experiments with blood plasma and lymph of 12 donors. Biochemical content indices of the main blood and lymph ingredients are used for controlled criteria of the sorption capacity. Those indices determine the ingredient concentrations that characterize the state of the cell, organ, and general homeostasis in various diseases. Findings Sorption efficiency of CNTs was demonstrated in relation to a number of ingredients of the plasma of blood and lymph. It allows considering CNTs as selective sorbents, which is of great interest for medical applications. CNTs have high sorption activity against a number of substances. The sorption efficiency of CNTs depends on the catalyst on the basis of which they were received. Microscopic comparative analysis of CNTs (Co) and CNTs (Fe) revealed significant differences in the structure of the agglomerates. Agglomerates of CNTs (Co) as against of agglomerates of CNTs (Fe) have a more compact structure and smaller size which seems to affect the sorption properties. Research limitations/implications Further studies involve the study of the toxic properties of carbon nanotubes and development of technologies for the chemical modifications for biocompatibility and improvement of the sorption properties. Originality/value The results may be of interest to the efferent medicine associated with extracorporeal detoxification of the blood and lymph, and life support systems. Sorbent specificity manifested most clearly with respect to bilirubin (BiliT). The average percentage of BiliT-elimination (removal) reaches more than 60% for plasma and 50% for lymph when using a CNTs (Fe). This result is of great importance, as is rarely to reduce BiliT-level by more than 30% using modern coal sorbents. High sorption specificity found also for Gluc, TR, and AlbG. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybaulin A. G., Sidorenko A. S. Stress state of an aircraft equipment structure with discrete welded connections at random kinematic loading. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 183-193. Spot welding method is widely used in load-carrying structures of flight vehicles. An essential disadvantage of spot welding is the stress concentration higher than the concentration in similar rivet connections. To estimate the structures durability the local stress state near the welding point must be computed. Some results of the mathematical of stress state of the load-carrying structures of aircrafts containing spot welded connections are presented. Stress state in the welding spots of the structures subjected to the random kinematic excitation is computed. The thin-walled cylindrical shell containing filling material that simulates the mass parameters of the structure are considered. The X-shaped wing and two attachment points are connected to the shell by means of spot welding. To simulate the dynamics of the considered structure with the discrete welded connections Solid Works software is used. Welded points are simulated by allocation of adjacent circular areas on the wing and the shell with constrained relative displacement. Each welded spot is subdivided to 40 finite elements. Dynamic computation of the structure is using the modal analysis for random processes. The dynamic stress state is defined for the kinematic loading by steady random acceleration. The spectral density of acceleration is set in a suspension point in the form of truncated «white noise». As a result of simulation the distribution root-mean-square values of equivalent stresses in the structure points is obtained. The greatest level of stresses is observed in suspension points. The basic part of vibration stresses dispersion is located near the frequencies corresponding to natural modes of the structure. Equivalent stresses fields along the seams are constructed. It is shown that the endpoints of seams are most loaded. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bugay I. V. Calculation of joint thermal and mechanical radiations action of on the orthotropic shell. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 194-199. A model and a numerical method are proposed to investigate both thermal and mechanical effects of radiation fluxes of various physical natures to thin-walled multilayered composite aircraft constructions. It is supposed that these actions can be reduced to non-uniform heating of construction, thickness change and formation of a non-stationary pressure profile on a surface. Applicability conditions of these assumptions are discussed. Computations of parameters of thermal and mechanical actions are carried out in quasi- one-dimensional approach (it is considered that thickness ofconstructions and spall sizes are significantly less than the radiation effects spot sizes). Earlier models of thermal and mechanical effects of radiation and uniform numerical code were used for carrying out these computations. The database focused in this problem is a part of a code. It significantly facilitates carrying out computing of thin-walled aircraft constructions. Deformation of thin-walled aircraft constructions damaged by radiation is considered on the basis of two-dimensional shell models. The dynamic equations are formulated for orthotropic uniformly heated shell of variable thickness and the constitutive equations proposed by Yu. N. Rabotnov for orthotropic materials are used. To solve the formulated initial-boundary value problem the finite difference schema is used. The general case of non-uniform spatial quadrangular grid is considered. Shear and tangential forces are defined in the middle of cells and both the displacements and the moments are defined in nodes. The schema has the second order of accuracy on temporary and spatial variables if the grid is uniform. Practical criteria of stability of the used schema are formulated using Neumanns criteria. Using the obtained numerical results the applicability of the developed approach, algorithm and software to estimate the performance of thin-walled laminated orthotropic composite structures of flying vehicles subjected to the combined thermal and mechanical effects of radiations fluxes is shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sidelnikov Y. V., Kalmykov N. S., Shevyrenkov M. Y. Using the method of control questions in marketing. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 200-207. Both the subject and the purpose of the articles research «Using the method of control questions in marketing (CQM)» are stated in its title. In our research, the authors demonstrated that the application of the CQM as one of the marketing tools could help to reduce the time and financial losses in R&D department of the company. Also, CQM together with kaidzen could establish a great source of new ideas and proposals for the modernization of the company. Until recently the description of using the CQM has been uncommon in the Russian marketing projects. In this work, we present the identification of the CQM. As a result, we showed that the principles of including the method to the list of CQM are the following: mutual purpose of study, specific form of description of the method text structure and, of course, the historical tradition. The possibility of using one of the options of the CQM (Parnes general-purpose list) for development of recommendations to reduce the negative effect of the crisis of ship-building market to the Board of these companies was demonstrated in this article. In our research, we presented and justified the use of not only the universal but also the specific lists of control questions in marketing. The full description of one of these methods can be found in the article. Also, we suppose that using different lists of CQM will greatly assist in solving economic problems related to the development of the new product. In our research, we establish the new hypothesis of the possibility of the joint use of the CQM and kaidzen. In our opinion, such combination could be very useful in various cases. Thus CQM in terms of kaidzen plays the following roles:
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Kindinova V. V., Shebeko Y. A. Simulation modeling of business process management product flow multinomenclature aviation spare warehouse. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 208-219. Purpose Develop a simulation model, reflecting the processing of commodity flow aviation spare. Use a simulation model to assess organizational measures aimed at improving the efficiency of the warehouse. Design/methodology/approach System analysis, statistical analysis and forecasting, simulation modeling, software engineering, technology of business process modeling, decision theory, planning theory of computational experiment. Findings The simulation model is implemented using the capabilities of the conceptual paradigm of System Dynamics in the operating environment software package Anylogic. System Dynamics approach was chosen, because it is rather adapted for modeling large-scale systems. System Dynamics approach allows to investigate the properties and structure of the system at a high level of abstraction, not modeling the whole set parameters of the system, but approach can quickly evaluate the work of the system. Simulation model models the flow of goods movement through all three stages of warehouse processing: stage I the acceptance; stage II sorting and placement; stage III completion and shipment. Simulation model consists of ten patterns, each of which implements the processing of flow of goods at one of the stages of warehouse processing. Each of the patterns is a graphical diagram causal relationships and global influence of some parameters on the other parameters over time. For each graphic diagram AnyLogic software environment automatically generates a system of differential equations, then the global system. Global system of differential equations is solved automatically by a given numerical method when running the simulation model for execution. In the simulations with the simulation model the balanced amount of human resources needed to ensure the processing of cargo traffic a given intensity in operating areas of the warehouse are calculated. Research limitations/implications Using the simulation model a number of practical problems for analysis and re-engineering processes of logistics companies has been solved. Originality/value The perspective technology modeling and analysis of business process management product flow aviation spare parts warehouse based simulation was presented. Simulation model can be used as an independent software module, as well as the software component of the complex simulation models. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golubev S. I. Market characteristics of a military-industrial complex aircraft. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 220-227. Market characteristics of an aircraft manufactured by military-industrial complex (MIC) are formed by two forces acting in opposite directions. The first force the cost of production is determined in accordance with the classical labor theory. The second force is utility; it characterizes how well the goods satisfy human needs. According to the utility theory, product gets its value through individual assessment of specific consumers. In the analysis the total utility is distinguished from the marginal utility, which is equal to the increment of the total utility when the consumption of goods is increased by one unit. The ideas and approach of the utility theory can be used for evaluating of the aircraft design options. Utility of the aircraft is the purpose and one of the design characteristics of the whole project development process, which is implemented in two stages process: transporting payloads to the area of the target and destroying of the target. During design process the goal is to develop a new version of exiting aircraft or create completely new previously unavailable vehicle. Concept of technical specifications and basic idea of the project are defined by the knowledge (the human capital). Implementation of the knowledge results in the aircraft new characteristics. It is proposed to consider the combat effectiveness as the utility function of the aircraft and use it to evaluate technical level of design options and range of possible market prices. Assessment of the aircraft utility is based on analysis of its target payoff. It is assumed that during the development stage of the new technology project the feasibility study is based on the hypothesis of proportionality of utility and price. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fomkina V. I., Shatlovskaya K. V. Assessment of influence of receivables volumes on the operational and financial risk level of the aircraft repair enterprises. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 228-233. The biggest part of financial assets of the aircraft repair enterprises is concentrated in receivables which represent the immobilized part of its own current assets, also they are distracted from a turnover of the enterprise and accumulated at clients. Researchers showed that with growth of a share of receivables in assets of the aircraft repair enterprise, level of the production lever grows. But even at the insignificant size of receivables in value terms, the size of the production lever will increase with a growth of a share of debt in enterprise revenue. For ensuring economic activity of the enterprises with financial resources it is necessary to minimize negative consequences from a big share of receivables in the amount of current assets. For expansion of market sales of the enterprise needs investment in the main production. During such investments the share of constant expenses, that leads to growth of operational risk, grows. Investment in the main production also increases financial risk which is caused by attraction of large volume of financial resources. The increase in volume of borrowed funds leads to growth of a financial leverage. Level of a financial leverage shows how many percent the net profit will change at change of operating profit for one percent. Net profit is influenced by revenue size from sales and rendering services which depends on receivables size. The volume of net profit, which the organization for satisfaction of the needs has, depends on volume and a maturity date of debt. Outstanding receivables can have catastrophic consequences for activity of the air enterprises. At high level of a financial leverage any delays in its payment involve serious consequences. Therefore management of receivables, its volumes and sources of emergence is an important task of the enterprises of the aviation industry. The assessment of operational and financial risk allows to avoid essential losses for the enterprise, and in certain cases to warn irreversible negative consequences. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Melik-Aslanova N. O. The analysis of the capital structure in the aviation industry. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 234-241. Change in equity is difficult and key task that enterprise faces. In order to analyze trends in the development of aviation enterprises in Russia, the equity capital structure and financing sources of enterprises with retained earnings, non-current and current borrowings as well as those with positive financial results and investment activity were considered. Thus, the «Irkut» Corporation has been developing successfully over the past three years and is involved in investments, in particular in manufacture of MS-21 short- and medium-range aircraft. Total project investments equal RUB 190 billion, RUB 70 billion of which shall be invested by the state. The project shall be completed by 2020. Therefore, the corporation is reducing financing of day-to-day operations and increasing the amount of long-term investment in the production of the MS-21. Considering the commercial credits, borrowings from enterprises and loan bonds, e.g. an interest-free loan of RUB 11,600 million with a payback period up to 2020 was received from the parent company OAO «OAK», whereby debt on loans and interest-free borrowings from OAO «OAK» equaled RUB 27,019,803 thousand. When calculating the effectiveness of raising the funds, we use a formula to determine the effect of financial leverage. By the financial leverage effect formula we can determine the influence of bank credit and bond on return on equity. A comparison of two options shows the need to justify the structure of all capital. Thus, return on equity can be increased by 1.9% through the issue of bonds. An increase in the share of loan bonds in borrowings or a reduction in the interest rate on bank loans will ensure a further increase in return on equity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Babenko E. A. Creation of the SaaS-application for competitive analysis in the aviation sector. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 242-254. The purpose of this research to develop mathematical models and algorithms for competitive analysis that would help to investigate the dynamics of inter-firm interactions (B2B) in the aviation industry (AI), and create software to use these models and algorithms, and design competitive strategy for the aircraft companies. Competition in the sector of aviation facilities (SAF) is a complex system, which includes not only aircraft manufacturers, but also certain types of aircraft (fighters of the 5th generation, unmanned aircrafts, etc), because their functions are often the same and /or overlap. Its subsystems are major manufacturers of aircraft, new entrants, substitute products, suppliers, customers and complementors (implicit market participants, which increase or decrease the attractiveness of certain products in the market). Elements of the system are intelligent agents that correspond to each of the considered subsystems. The structure of the system is a multi-layered fractal graph Г(Fik), where k — type of force (the main competitors, suppliers, etc.), i - level of the hierarchy, whose vertices are the elements of the system, and edges the relationship between them. This representation of the SAF or all aicraft market enables companies to analyze the situation in the market in its entirety and with the maximum number of relationships, which in turn provides the optimal production strategies. The mathematical model were created to describe the interaction of agents based on the theory of compromise gaming and algorithms initiation model of competitive analysis (CA), and the method of calculating the results of the CA, allowing decision-makers from the manufacturer of aircraft to make strategic decisions. It was also designed and developed the software in the form of SaaS-application CA (API, architecture, database design, etc. have been developed by). Results of SaaS-applications are profits schedule as a recommendation for decision-makers in the allocation of market shares of its main players and recommendations for choosing of competitive strategy. Thus, we have shown that a systematic analysis of competition in the airline industry is highly relevant, and it requires the development of new models and methods. Competition in the SAF is presented as a complex system whose elements are the agents-companies. To describe the interaction of agents, a set of mathematical models and algorithms was created, as well as methods of calculating the results of the SC. For the application of mathematical models software was developed and tested as SaaS-applications for spacecraft manufacturers OAT to develop a marketing strategy of one of the manufacturers of the aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorontsova V. L. Analysis of the behavior of cycles limit under the increase of the orbit eccentricity and under the change of aerodynamic parameters. Aerospace MAI Journal, 2013, vol. 20, no 1, pp. 255-258. Orbit is considered as «a bunch of bodies» two material points connected by flexible massless inextensible thread as a system with the released bond. The equation of associated motion with the forces of gravity gradient, aerodynamic pressure gradient and aerodynamic drag of friction are used [1, 2]. In this article were taken into consideration the behavior of the limit cycle for the equation of the relative motion of the gravitational effects of aerodynamic pressure, aerogradient and dissipative factors [2], depending on the growth of the eccentricity e and aerodynamic parameter a. The effect of the ellipticity of the orbit of a possible chaotization movement is considered. The known methods of nonlinear mechanics are used for research: the method of Lagrange equations of the first kind, the method of phase plane, numerical implementation of the method of point mappings, theory of stability of motion. A comparative analysis of the phase portraits of the orbit with a very small ellipticity e 0.001= (case 1) and with the increase of eccentricity to e = 0.01 (case 2) are carried out. If the eccentricity of the orbit is increased by an order for the same values of aerodynamic parameters a and values and the density gradient along the dumbbells k and aerodynamic dissipation b (k = 1; b = 0.01), the location of the limit cycle will be much higher. As a result of comparative analysis, as well as in [4], we can conclude that values of the angular velocity α' in turn we can consider as a result of the growth of the values of parameter. When approaching the maximum value a achieved, the values α' are differ more than one unit. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubov Y. B., Zhelonkin V. I., Khrabrov A. N. Research of manoeuvrable aircraft Wing Rock oscillations at high angles of attack . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 5-13. Self induced wing rock oscillations of a maneuverable aircraft model in wind tunnel are considered. Self sustained oscillations are connected with the time delay in unsymmetrical part of roll moment coefficient. The results of mathematical simulations are compared with corresponding experimental data, obtained with one degree of freedom in roll dynamic rig. Mathematical modeling of aircraft full dynamics with automatic control system are considered also. The possibilities of deflected thrust vectors for suppression of self induced oscillations are investigated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Ivanov N. A., Kolesnikov V. A. Methodology and algorithm determining the temperature dependence of thermal and physical characteristics for anisotropic materials basing on an inverse problem solution. Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 14-20. Developed a methodical approach, algorithm and computer program for determining thermal characteristics are widely used in aviation and space technology anisotropic materials. Methodical approach is based on a solution of inverse heat conductivity problem stated as an extremal one. The effectiveness of the use of the recommended approach is illustrated by the example of recovery of the thermal conductivity tensor and volumetric heat capacity of the composite perspective on the results of physical experiments with a sample of this material. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhigastova O. K., Pochukayev V. N. Command constructions. Using command constructions during automated planning of automatic spacecraft mission . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 21-31. In this article we consider command constructions created for making of mission plan in automated way. There are five different kinds of command constructions. We consider their structure, set of elements and connections between them. There is an example of using command constructions during the planning of automatic spacecraft mission. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Oleynikov I. I., Pavlov V. P., Kovaleva M. V. Methods of identifying and estimating the parameters of dangerous situations, while ensuring the security ofspacecraft flight security in the near earth space . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 32-37. Methods and algorithms for monitoring of hazardous situations for spacecrafts,which are controlled from MCC FSUE TSNIIMASH, were developed. These methods are universal and can be used for any type of orbits and any set of measurement tools. These algorithms are the basis for the software package which is used for prevention of dangerous situations in the near-Earth space. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Elnikov R. V. The analysis of a transfer Earth Mars with a lunar gravity assist maneuver and use of a small thrust . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 38-44. This paper describes а main results of analysis of the interplanetary trajectories «Earth-Mars» which use a lunar gravity assist maneuver. The space transportation system, which consists of the launch vehicle «Soyuz 2-1b», the upper stage «Fregat» and a space vehicle with two electric propulsions «SPT-140D» is considered in the article. The comparison of flight schemes to Mars with and without the use of lunar gravity assist is presented. The winning final spacecraft mass from the effects of lunar gravity assist maneuver is assessed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N., Kokushkin V. V., Borzykh S. V., Voronin V. V. Dynamics of process of landing of the spacecraft winh an landing gear consisting of arm and cord . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 45-50. Dynamics of landing of the spacecraft equipped of original landing gear consisting of arm and cord at interaction with a landing surface is considered. The mathematical model of process is developed, motion stability research is executed. Comparison with a case of use of a conventional landing gear consisting of spring and damper is conducted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molchanov A. M., Bykov L. V., Donskikh V. V. Simulation of high-altitude rocket engine jet with vibrational relaxation . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 51-60. The work is devoted to the study of energy exchange and relaxation processes occurring in the gas jet exhausting from a model rocket engine. It is shown that at high altitudes, temperatures of different vibrational energy modes differ significantly from each other, as well as from the translational-rotational temperature. Vibrational temperature fields depend strongly on the spontaneous radiative deactivation. The paper presents the results of calculations obtained by using various data on the kinetics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shirokov I. N., Abashev V. M. The simulation of the working process in the mixing chamber through the tree-section burner with forced air supply . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 61-64. A general principle of operation and a brief history of the multicircuit direct-flow combustion chambers on solid fuels are revealed. The design of an adjustable model mixing chamber is proposed, in which instead of a solid fuel charge three-section burner with forced air supply is used. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. The modeling of physical and chemical processes in the current sources with an aluminum anode of the power plants for aerospace systems . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 65-71. This research presents a physical-chemical model of the work processes proceeding in the mechanically rechargeable air-aluminium (AAC) and hydronic (with aluminium anode) electrochemical cells (EC) which allow to create new highly efficient independent power supply sources for aerospace systems and other technical fields. The work reviews two electrolyte types: the alkaline and the neutral salt ones. The model has been developed on the basis of the experimental data obtained by us. The work contains the equations of cathode and anode processes and also of the processes running in the near-electrode areas and electrolytic solution. It offers the stage behavior schemes of the electrode reactions and explains the influence of the discharge rate on the processes of aluminium cathode corrosion. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demskaya I. A., Raznoschikov V. V. Technique for determination new structures of the alternative fuels . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 72-80. The paper represents the computer code for computation of the thermo-physicals properties of the alternative fuels and obtained results of optimization researches of the best compositions of the studied fuels. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Medyakov O. E. The use of mathematical model of an experienced engine the bench tests in the real-time mode . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 81-88. Sets out the principles for high-speed mathematical model (MM) designed for bench tests of experimental gas turbine engines. Gives the analysis of the characteristics of the development of one of the MM prototype engines. Methodology provides a practical application of the MM. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Magerramova L. A., Vasilyev B. E. The influence of crystal orientation on the stress-strain state and strength of a turbine blade . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 89-97. This paper discusses the influence of the crystallographic orientation on the stress-strain state and the static strength of single crystal nickel-based blades of high-temperature gas turbines using finite element analysis. A calculation method of static safety factor is provided. This method was used to estimate the optimal crystallographic position in two single crystal blades. The scatter of static safety factor in tolerance on the crystallographic orientation of the casting is analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A., Mitin S. P., Barykin I. Y. The analysis and specification of formulas of calculation of losses of efficiency of turbines with a bandage at a partial supply . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 98-102. Methods of calculation of losses of efficiency of the axial turbine with the driving wheel with a bandage are analysed at a partial supply, results of a complex pilot study of axial turbines are presented at change of gaps and a number of parameters, settlement research and on the received results is carried out them formulas for turbines with a working wheel with a bandage are corrected. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yudin V. N. Counteraction of radar station in a mode of search in a corner hindrances with the operated capacity . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 103 -107. The article deals with anti-aircraft radar direction finding for the protection of this aircraft, which can be achieved by setting up radio direction finder active noises of various types. Determine the desired output noise control law of self-defense, and to obtain quantitative estimates of the size of zones of uncertainty of the angular position of the protected aircraft suppressed radar (SAR) provided when creating noises with controlled power. Consider the case of the formation of a relay type of noise, which is typical for modern technology of electronic warfare. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bokhin D. L. Features of construction of the digital receiver modules array . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 108-113. Presented an overview of development associated with the digital antenna systems over the past few years and the methods of reducing the hardware requirements of such systems. A circuit model of digital receiver module array was achived. There was also a method of digital beamforming using digital fractional delay filters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsov D. A., Voronina L. N. A new method of providing of parallel inverters operation . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 114-130. The paper considers a method of parallel inverters operation, consists in inphase synchronization of setting generators. One of main lacks of this method is using of a mode «leader-conducted», which sharply reduces reliability of system. In this connection the new method of synchronization is offered. It based on independent mode of generators operation. Thus the information bonds, entered between generators, allows to synchronize generators not only on a phase, but also on frequency and amplitude. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitushkin A. M. The method of parameterized data collaborative distribution in multi-agent system based on dynamic constraints . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 131-137. In this paper the author developed a method of distribution parameterized data in multi-agent system through the collaboration of agents, based on the approach to the problem of distributed constraints satisfaction. Author proposed a formal model of data distribution. Furthermore, introduced dynamic constraints, modified algorithm of asynchronous backtracking. Author formulated and approved theorems concerning the process of solving the problem of distribution parameterized data. The experimental results of distribution of data about available resources in a multi-agent system, show its effectiveness. The proposed method allows to solve the problem of detecting multiple targets by a group of autonomous unmanned aircraft by reducing this problem to find the states of agents in multi-agent system satisfying the imposed constraints and allows it to formalize the task, and takes into account both distributed and dynamic aspects of this problem. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brekhov O. M., Mew T. . Optimization of query processing in a multi-database . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 138-146. In this paper is proposed a plan for optimizing the query execution time while accessing the database based on ordering the conjunctions of elementary queries, forming the entire or part of the request what is relevant for aerospace systems. An expression is given for the minimum request execution time for an ordered set of elementary requests in accordance with the required system of inequalities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brekhov O. M., Nguyen Q. T., Pham X. T. Optimization techniqueof risk control for the safe operation of aircraft . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 147-151. In this paper the problem of risk control solutions for security systems is proposed based on the optimality of such tasks as comparative evaluation of object protection, the impact of various system parameters and conditions to achieve the desired level of security, identify the weak parts of aircraft systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gruzdev A. I., Kulikov N. I., Makarenko A. V., Sorokin A. E. Specialized power supplies on the basis of lity-ionnykh storage batteries . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 152-157. On the basis of a comprehensive approach the current state of development and a scope lithium-ion accumulators is considered. Their competitiveness in comparison with alkaline and acid accumulators is shown. System approaches and the skhemo-technical solutions used at design lithium-ion storage batteries with microprocessor monitoring systems and managements are analysed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Tran N. D., Le T. H. Research stress strain state of cylindrical shell under the refined theory . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 158-171. Under the refined theory is considered axisymmetric cylindrical shell for two cases sought displacement approximation by polynomials in the normal coordinate. The basic equation of the displacement and the boundary conditions, obtained by minimizing the energy functional of Lagrange. Two variants of a refined theory of determining the stress strain state conventionally called «K = 2» and «K = 3». In the case of K = 2 tangential displacements are represented as squares of polynomials, and deflection linear polynomial in the normal coordinates. In the version of K = 3 approximation movements made ??by one degree higher than in the case of K = 2. The analytical solution of the boundary problem for the option of a refined theory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov K. M., Vinnik P. M., Ivanov V. N. Mechanical properties of materials under compound loading . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 172-181. This article contains the examination of variants of univocal definiteness of deformation process. Here are defined necessary and sufficient conditions of fulfillment the first deformation monotony condition. These conditions are applied to deformation analysis in different situations. It determines conditions of unambiguitys existence and its character in these situations. This article shows possibility of practical application of these conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Svetushkov N. N. The geometric integrals method in modeling the processes of heat conduction with phase transformations . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 182-186. To solve the problem of heat conduction in the media with temperature depended characteristics were applied approach, which generalizes the previously developed method, named «geometric integrals», for solving problems of heat transfer in heterogeneous media. This approach allows to arise the chained system of integral equations for solving 2D tasks with complex geometry. A distinctive feature of these equations is that the integral operator kernel has no singularities, and therefore the numerical solution derived no additional complexities associated with the need in some way to consider the special points (the points of discontinuity). This problem formulation allows one to perform uniform calculations over the entire solution area, including the near the boundary regions for geometrically complex objects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuprikov M. Y., Martynova . . Expert system of automated design mock-up FORMOS . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 187-191. The expert system FORMOS for automation the design mock-up facilities of aircraft was considered. The structure of the system was considered, the mechanisms of interaction between the blocks were described. The individual fragments of the system and a set of rules were detailed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tumashik G. A., Frumen A. I. Examination static and dynamic strength of a cylindrical shell, contacting with a circular diaphragm . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 192-196. The stability and strength of a cylindrical shell with unilateral contact with internal circular diaphragms are investigated using finite element method in nonlinear problem statement. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shklyarchuk F. N., Rei J. . Calculation of axisymmetric vibrations of shells of revolution with liquid by finite element method . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 197-204. New variant of the finite element method is developed for calculation of axisymmetric vibrations of elastic orthotropic shells of revolution partially filled with liquid taking into account ring ribs and the preliminary stress-strain condition. The compatible finite elements are narrow ring strips of the shell with the internal liquid lays. The axial displacement of liquid in the cross section is represented as a sum of plane displacement and distortion in shape of parabola. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Girin A. M., Povoljaev S. T. Settlement and experimental study of the sustainability of multilayer cylindrical shell . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 205-209. The article describes the method of calculation of cylindrical shell the complex structure of the walls, under the influence of uneven ambient pressure and compressive load. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilin A. N., Karandin V. I., Kuznetsova E. L., Rabinsky L. N., Rozhkov A. G., Yanovsky Y. G. Synthesis of carbon nanotubes based on CVD continuous technology . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 210-215. This paper presents a comparative analysis of a few modern technologies for the synthesis of carbon nanotubes (CNTs). The most cost-effective and promising CVD-method (Catalytic Vapor Deposition) is considered. Under this method, CNTs are formed by vapor transmission carbonaceous feed over a heated catalyst. There is a number of disadvantages of this method, one of which is its frequency (the impossibility of continuous technology) and inefficient consumption of carbon-containing raw materials and related inert gases. A modification of the CVD-method is suggested allowing significantly improving its efficiency and achieving greater productivity in the continuity of the process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuznetsov E. B., Ananyev R. Y., Guljaev D. A. Limit state of the elastoplastic aircraft constructions . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 216-221. An algorithm of a numerical solution to a static problem, modeling large displasements and deformation of bodies, produced of elastoplastic materials, is suggested. The finite element method and the method of continuation with respect to the best parameter are used. After discretization the problem transformed to solution of initial-value problem for a system of ordinary differential equations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Borodin A. I., Streltsova E. D., Kovalyova A. V. Economic-mathematical model of the assessment of strategic risk . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 222-232. In article the complex of the economic-mathematical models, allowing to estimate size of strategic risks is constructed at a choice of strategy of development of the industrial enterprise on the basis of imitation of processes of change of the current profits and losses of the industrial enterprise in the conditions of the uncertainty, including models of an assessment of laws of distributions of profits and losses, both at existence, and in the absence of retrospective statistical data. On the basis of the created economic-mathematical models the software product of STRATEG is developed for decision-making process support at a choice of strategy of development of the enterprise taking into account strategic risks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mikhailova E. A., Sbitnev S. N. Pull mechanism of the production management at the aeroengine venture . Aerospace MAI Journal, 2012, vol. 19, no 5, pp. 233-242. The authors propose a business-processes classification of production planning and recording at the enterprise, which activity is manufacturing the aircraft engines, developed a pull system, organizational control mechanism, described the algorithm for implementation of an automatized control system of production planning and recording. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grumondz V. T., Polishcuk M. A., Chertorizhskaya S. S. The choice of the pilotless plane vehicle dynamic image. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 5-12. The problem of the aerodynamic and dynamic choice of the pilotless plane vehicle (PPV) is considered. This choice provides the improvement of the flying and dynamic characteristics. The task is solved by the involvement of the new elements for the design of PPV. These elements are wing of high aspect ratio and air-dynamical drive. The mathematical model of the PPV motion and the solution algorithm of the task were created. The aerodynamic characteristics allied with this algorithm and parameters of the angle stabilizing and guidance system were chosen to provide the flying range maximization. The algorithm for these tasks allied with the task of flying around determined navigation points and the task of maximization of the pitch angle at the end of the trajectory was designed. This work is urgent for the most of the PPV guidance tasks. The results show that the maximum flying range can be increased at least at 75% in comparison with the modern units of this technical class in Russia. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lebedev G. N., Aung M. T., Dao N. T. Estimation of conditions of steady preservation of efficiency of industrial production of aviation technics in crisis situations due to perfection of technology of its manufacturing. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 13-19. The problem of preservation of a production efficiency of aviation technics in crisis situations due to optimum control of processes of reproduction and perfection of manufacturing techniques of production Is formulated. The expediency of initial expansion of manufacture and fast perfection of technology during the favorable period is shown to keep a demanded level of development of the enterprise during recession. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Poltavets G. A. Estimate of efficiency of distinct types of space systems. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 20-31. Broad spectrum of performance criteriaof principal, supply andauxiliary systems is represented in the study. It is necessary to take into account that distinct types of systems influence the efficiency of major task solution. Suggested methodology of the accounting is based on the correlation between performance criteria and qualitative and quantitative evaluations. Stated systemic criteria of optimality and decomposition allow to widen capabilitiesto use dynamic programming methods. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bondareva N. V., Koroteev A. A., Lebedev A. V., Sheludyakov V. D. Development of linear α, ω-bis(methyldiphenylsilyl)oligodiorganosiloxanes synthesis process. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 32-39. Describes the methods of synthesis of pentafenyltrimethyltrisiloxan basic chemical compounds for use as a working body of frameless drainage systems low-potential heat in microgravity conditions and deep vacuum. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komissarenko A. I. Determination of missile angular position in relation to wind speed changing as per power law. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 40-43. The article relates to determination of the missile angular position under the action of wind velocity which changes according to the power law of altitude function. The missile moves vertically. The analytic dependences of the attack angle, the velocity vector angle of the altitude function and the wind velocity degree which features atmosphere stratification were obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kulkov V. M. Creation of a complex of design models for the parametrical analysis of small spacecrafts with electric propulsion thrusters. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 44-55. The complex of models of design researches of the unified space platforms (USP) of small spacecrafts (SSC) with electric propulsion units (EPU) for the analysis of their design aspect on the basis of scale transformations is presented. The actual problem of modeling of design parameters of the USP of various dimensions proceeding from known similar development is considered. Influence of scale on characteristics of EPU and its subsystems is investigated. In the methodical plan the approach to a solution of the problem of creation of family of small space platforms of different purpose is created. Mathematical models for design researches and the analysis of characteristics of SSC with electric propulsion thrusters (EPT) on the basis of stationary plasma thrusters (SPT) are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev V. V., Starkov A. V., Fedorov A. V. Methology of actualizing of electronic data bank for space purposed objects. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 56-64. For space sphere new technology of data bases is needed, which could allow reliably and effectively manage big amount of heterogeneous data. This technology should support not only numeric data, simple tables, which are used in control, but complicated objects. Program architectures problem, models of data and means of organization crossplatform interaction of system of information provision for space purposed objects are considered in article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovalenko A. I., Petrash V. Y. Formation of design solutions of unmanned aerial vehicles in the program-information environment of the knowledge base. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 65-72. Methods, mathematical models and the program- information means of the object-oriented knowledge base intended for formation of design solutions of alternative options of unmanned aerial vehicles are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kravchenko L. L., Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. Evaluating the effectiveness of controlled hydrogen generator for the oxygen - hydrogen fuel cells. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 73-80. We considered the concepts of combined power plant (PP) for the aviation and space rocket technology consisting of an oxygen- hydrogen (O2/H2) electrochemical generator (ECG) and a controlled hydrogen generator based on hydronic chemical current source (CCS) with an aluminum anode. Their advantages and disadvantages are shown. The theoretical calculations of power and current- voltage characteristics of PP are executed. A preliminary estimation of parameters of controlled hydrogen generator based on the hydronic CCS for O2/H2 ECG with nominal power of 1 kW is developed. The calculation showed that on the basis of hydronic CCS with an aluminum anode it is possible to create a hydrogen generator with electrochemical control of its escape rate in a wide range. It was first shown that the application of a combined PP is safe and effective solution of the problem of hydrogen storage for autonomous PP as space and terrestrial applications. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yanovsky L. S., Ezhov V. M., Molokanov A. А. Standart requirements of national and foreign lubricants for aircraft gas turbine engines. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 81-85. Because of necessity of developing a new system of aviation oil approvement for use on aircraft this article describes normative requirements to domestic lubricants in comparison with foreign specifications (MIL-PRF-7808, MIL-PRF-23699 and SAE AS5780). The article identified the differences between the existing domestic and foreign requirements to aircraft turbine oils. In order to harmonize the domestic methodology of aviation oil approvement for use on aircraft with foreign practices proposed to develope national specifications for aviation oil. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Medyakov O. E. Control conditional measurements in bench tests of gas-turbine engine using the information-measuring system. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 86-93. The control methods of conditional measurements were considered at bench tests of gas-turbine engines with use of information-measuring system (IMS). It was given the characteristic of the developed program complexes providing this control at rate of experiment and entering into the development of IMS. The methodology of practical application of this IMS was described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yampol'skii S. M., Rubinov V. I., Golovin V. Y. Management of maintenance service and repair of aviation technics during carrying out of the analysis logistical support. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 94-99. The problem of calculation of periodicity of performance of works in maintenance service and repair of a product of aviation technics in view of his reliability, depending on characteristics of his completing elements and from the location of elements in the block diagram-logic of reliability is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilyev B. E., Magerramova L. A. Creep equations forming of alloys for calculations of stress-strain state kinetics of high temperature gas turbine blades. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 100-108. The blades of high-temperature gas turbines working in conditions of prolonged loading nonuniform temperature field and the external forces. The properties of alloys of the blades are changing over time due to the phenomenon of creep. A method of determining equations coefficients for calculating the stress-strain state kinetics of turbine blades using the finite element of ANSYS on the example of a modern blade alloys is provided. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A., Mitin S. P., Barykin I. Y. The analysis and specification of formulas of calculation of losses of efficiency of turbines with a bandage at a full supply. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 109-114. Methods of calculation of losses of efficiency of a axial turbine stage with the driving wheel with a bandage and without a bandage are analyzed, settlement research is carried out them and known formulas for turbines with the driving wheel with a bandage are corrected. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dunaev V. V., Gromov V. F., Eryomin M. V. Influence of stresses in mechanical joints on the high-strength alloy d16t corrosion resistance. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 115-119. There are given results of experimental research influence on the corrosion distruction of aluminum alloy D16T structure elements under the action of radial tension tensile stresses in mechanical joints. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aleshin B. S., Maximov V. N., Chernomorskii A. I., Plekhanov V. E. Integrated measurement navigation system for uniaxial wheeled module. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 120-128. Algorithms for integrated measurement navigation system based on EKF and UKF and installed on uniaxial wheeled module were reviewed. Comparative analysis of two approaches conducted. A navigation system primary sensor set includes micromechanical accelerometers and gyroscopes, odometer, global navigation system receiver. While developing correction scheme for the system, nonholonomic nature of wheel-surface interaction taken into account. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Busurin V. I., Kazaryan A. V., Zheglov M. A., Zwe N. Z. Simulation of the pressure transducer based on optical tunneling effect with adjustable measuring range. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 129-134. This article describes pressure transducer based on optical tunneling effect, which is used in the construction of piezo actuator controlled by feedback loop. Produced by modeling of the static and dynamic characteristics of the transducer with adjustable measuring range. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stepaniants G. A. Structure of control of unstable object, which provide minimum of the integral of aquare of control. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 135-140. This article considers control of unstable linear object. The control algorithm provides the minimum of the integral of square of control signal. It is shown, that such algorithm is symmetrically moving the characteristic values by right to left of complex plane. The characteristic values, which were in left half of complex plane dont change its positions. The proof and example are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goryashin N. N., Lukyanenko M. V., Solomatova A. A., Khoroshko A. Y. Analysis of parallel operated zero-voltage transition converters. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 141-146. The advantages of zero-voltage transition converters in comparison with conventional PWM power converters under parallel operating for common load of space craft power system are shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krasilnikov P. S. On the non-predicative concepts in classical mechanics. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 147-155. The non-predicativity of some fundamental concepts of classical mechanics is investigated. The non-predicativity leads to closed circles of reasonings and, as a consequence, to weak concepts and proofs. It is shown that the non-predicative judgments contain in a classical method which use dAlemberts principle for the calculation of constraint forces, in the concepts of force, in well-known proofs of dAlembert-Lagrange principle, in some methods of the theory of oscillations. In many cases it is possible to find and remove a reason of the non-predicativity and, as a consequence, to get rigorous proofs of theorems. After removal of the non- predicativity, a traditional method of the calculation of constraint forces is substituted by the calculations of constraint forces which are considered as the functions of co-ordinates and velocities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikulina E. N., Trubina A. V. Information support of valuation activity through the example of aviation enterprise. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 156-162. The Article shows actual problems of searching of information necessary for enterprise valuation, as a tool of the company (and its capital) effective and competent management. Authors of article focuses attention on existing disadvantages of the regulatory and legal framework imposing restrictions on supplying and distribution of information for valuation. The article discloses information sources, useful for valuation of various industries enterprises and offers a ways of optimization of information search by creation a valuation uniform national database to be posted on the Internet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Burdina A. A. Problems of development of innovation activity in the aviation enterprises. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 163-173. In modern economic conditions the effective management of innovation activity of the aviation enterprise is a key factor of its competitiveness and efficiency. However, the management of innovation activity is hampered by a number of reasons. In the article there are considered the problems of development of innovation activity in the aviation industry. Analyzed the problems of education and disparities in the distribution of intellectual resources. Special attention is paid to the analysis of problems of the efficiency of the innovation infrastructure and innovation financing, the problems of human resources. Assessment of International comparisons of gross Domestic Expenditure on Research and Development. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Afonina O. A., Daynov M. I., Kirichenko N. V. Introduction of environment management system as a means of increasing the competitiveness of aviation companies. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 174-181. In article importance and urgency of problems of introduction of actions of ecological management at the aviation enterprise according to the international requirements of GOST R ICO 14001 is emphasized with the purpose of increase of competitiveness of production. Social, ecological, economic aspects of the given problem are analysed, formulas for calculation of social and economic parameters of introduction of system of ecological management are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakhirkin M. V., Zinchenko A. S. Quantifying IT forecast quality for the analysis of projected data. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 182-186. This article describes Quantifying IT forecast quality. Author analyzes project activities and problems of the existing metrics. Suggest a new baseline metric for the class project of the organization. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Manturov D. V., Kalachanov V. D. The organization of production of the knowledge-intensive production in the aviation industry of Russia in modern economic conditions. Aerospace MAI Journal, 2012, vol. 19, no 4, pp. 187-192. The technical and economic analysis of a current state and prospects of development of competitive production of domestic aviation equipment is carried out. The main directions of innovative development of the aviation industry of Russia, including within formation and implementation of federal target programs and creation of a perspective scientific and technical reserve are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitchenko Y. A. Phenomenological model for boundary conditions on a solid surface ... Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 5-14. Dependencies for velocity slipping and temperature jump within the broad range of Knudsen numbers are proposed. Phenomenological approach is used for forming molecule distribution function in the boundary point. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makarov A. F., Gromov V. F., Dunaev V. V., Eryomin M. V., Makarov P. A. Shear performability of prestressed bolted joints . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 15-18. It was examined experimental complex joint effect of fit radial tension and tightening on the bolted joint durability under the fatigue test/ It was determined the friction force effect along hole side on the cycle number up to samples failure and joint failure nature change depending on the value of joint pressing under the assembly. It was estimated the possibility of joint durability increase under the additional joint pressing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yampol'skii S. M., Golovin V. Y., Rubinov V. I. Model of functioning of perspective system for the automated planning actions of engineering-aviation maintenance . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 19-26. Questions of increase of a management efficiency by engineering-aviation maintenance (EАM) educational operations of aviation parts due to application of the automated planning are considered. Models of functioning of existing and perspective system for planning actions EАM are considered. Detailed temporary parameters of process of planning of actions EАM for existing and perspective system are received. The example of the automated development of a plan of measures of engineering-aviation maintenance of educational operations of an aviation part is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pisarenko V. N. Means of maintenance of an acceptable level of an air safety . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 27-34. The condition of an air safety in a civil aviation of Russia is considered, are investigated means used on foreign airplanes such as Airbus, intended for rendering assistance the measures on control of an acceptable level of an air safety are offered to crews of aircrafts on safety control of flights and. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dolgov O. S., Kuprikov N. M., Lyakishev M. A. Inertia-moment layout formation of regional passenger aircrafts . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 35-43. Describes the process of regional passenger aircrafts inertia-moment layout. Analyzed the effect of inertia-moment characteristics changing on aircraft shape formation. Defined main parameters of the power plant, fuel tanks, payload, aircraft systems, which have the considerable impact on the inertia-moment characteristics of the aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Usachov V. E., Ezhov A. S., Simonov A. V. Two-level optimization of the research mission in the near Sun space with advanced space technology . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 44-53. The article discusses the methodology and some results of optimization of the research mission in the near Sun space using gravity assists from the planets and low-thrust propulsion, in particular, electrojet propulsion system. A wide variety of options for the mission does not allow to seek a solution of the problem within a one class of ballistic schemes implemented by a single base space complex. Therefore, multicriterion optimization of the mission is proposed to carry out of the two-level scheme: first, within each class separately and then among competing variants. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bondareva N. V., Koroteev A. A., Lebedev A. V., Sheludyakov V. D. Ultra-high vacuum liquid for open space drainage systems low-potential heat . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 54-61. Justified the choice of ultra-high vacuum liquids, potentially suitable for use as a working body of frameless drainage systems of low-potential heat into space. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Poltavets G. A. The global model of three-level compound system . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 62-75. Compound system is described with the global model, which combines three levels of objects of local complex models: coordinator, active and passive systems.Mathematically, the connection of levels is described by the instrument of set theory.Theory of multilevel hierarchical Mesarovic systems is used. But it is considerably upgraded. The transition from analysis of operational phase (Mesarovic theory) to the life cycle study of the large engineering system is made. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorbatenko S. A. Application of the concept of inverse problems for the construction of the laws of motion control hydrostatic unit. Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 76-80. The use of published theoretical results on inverse problems of dynamics for building control laws the state of aerostatic class of aircraft. This article should be considered as a natural continuation and development of the results stated in [1, 2]. It is shown that the features of this class of devices, as an essential nonlinearity of models of motion and the variability of characteristics of the machine has successfully carried the methods of inverse problems of dynamics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoylov S. Y. Metods of Registration of aberration of Earth monitoring images affixment with analytical method . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 81-87. The article describes aberrations that affects on space images affixment errors and analyzes calculation model of aberration of image affixment with analytical method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev V. V., Kabanov D. S. An optimal insertion algorithm with parameters correction of the controls structure for automatic underwater vehicle . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 88-96. This paper deals with an optimal algorithm with parameters correction of the controls structure, designed for an automatic underwater vehicle (AUV). The controls structure is formed using Pontryagins minimum principle. This algorithm forms an optimal trajectory of AUV and works stable under changing terminal conditions. A developed AUVs stabilization system calculates optimal rudder deflection angles which are required to hold the AUV on the optimal trajectory. Numerical calculations of AUV dynamics using the simulation model are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhigastova O. K., Pochukayev V. N. Method of automated planning of automatic near-Earth spacecrafts. Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 97-103. This article examines method stages of automated mission plan development for near-Earth automatic spacecrafts. Also it examines the stages of mission plan checking with a use of imitation model of onboard control system. This article shows the efficiency of this method in comparison with manual mission planning method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Farmakovskaya A. A., Shtyrlin A. F. The properties of working medium of colloidal electro rocket thruster . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 104-109. It the article the results of the experimental research of physical and electrochemical properties of working medium based on concentrated solution of sodium iodide in glycerin are present. The obtained experimental data can be used for calculation and analyses of thruster characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makarov P. V. Experimental investigation of GTE fan 2stage blade flutter under different interraction between blades shrouds . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 110-120. Results of full-scale engine test under atmosphere condition and different interaction between fan 2stage blade shrouds is considered. The methods and sort of measurement and scheme of different sensors installation are discussed. It is shown, that the affected set of contact and non-contact sensors together with special methods of processing results of measurements give a possibility diagnosis of blade flutter with high level of reliability. It is obtained that if there are gaps more than 2mm between blades shrouds of fan 2stage flutter of this blades is appeared under atmosphere condition but when the rotation speed will be more than 70% from maximum. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leontiev M. K., Lanevskiy Т. M. Calculation of crack stress intensity factor in high pressure turbine disk . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 121-127. The article presents the methodology of calculation of crack growth rate in the turbine disk. The issues of constructing of a finite element mesh associated with the need to limit the number of finite element computational model are considered. Stress intensity factors for two cracks in the hub of the simulated disk in high pressure turbine are compared. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Berdnikov A. V. Method direction finding with using UWB signals in the antennas of large dimensions . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 128-134. The method of radio direction finding based on analysis of forms of ultrawideband (UWB) signal radiated by antennas with large dimensions is offered. The results simulated work radio direction finder (RDА) with using UWB signals is described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krinetsky E. O. Agent-based model in studying the processes of planning behavior of grid networks . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 135-142. Development of modern regional aircraft, rocket and space technology for the minimum time and cost is not possible without the involvement of modern computer technology and IT-technologies, which include grid technologies. Working prototype of the software simulator of grid infrastructures was developed with the help of agent-based simulation approach to the environment, AnyLogic 6.0. The simulator provides a tool support and the possibility of dispatching simulation experiments to study the behavior of different architectures in solving the metacomputing resource-intensive tasks of the space industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churkin V. M., Churkina T. Y. The Analysis of free oscillations parachute Systems with elastic line . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 143-148. Consider the motion in the vertical plane parachute system (PS) with elastically suspended load. In writing the equations of motion of the load model liruetsya material point, the dome axisymmetric solid, strictly nN two linear weightless springs. Compiled simplified the nonlinear equations of perturbed motion of the system, which take into account the non-linear dependence of the normal component of the aerodynamic forces of the dome pa-rashyuta the angle of attack. The method of harmonic linearization are expressions of defining the boundaries of stability regions and the main parameters of the vibrational modes arising from the motion of the system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panteleyev A. V., Metlitskaya D. V. Generation of genetic algorithms for search of optimal control by average speed of air-to-air missile. Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 149-159. The solution of an optimal control problem of the speed of the air-to-air missile by means of genetic algorithms with binary and real coding is offered. Technical and mathematical formulations of the problem are described, the algorithm of the solution is offered,and on basis of the algorithm the corresponding software is created. The approximate solution of an optimal control problemis provided and comparison of results with other methodsis made. The comparison shows efficiency of the created algorithms. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobiev I. N., Grishanina T. V., Shklyarchuk F. N. The nonlinear vibrations of the satellite with an elastic beam loaded by solar heating . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 160-169. In this article is solved the plane problem of the nonlinear vibration of the satellite with an elastic beam loaded by solar heating. The finite element method (FEM) has been used to solve the nonlinear problem. Different cases of the nonlinear vibrations of the gravitational stabilizing rod loaded by non steady solar heating have been considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Roy R. I., Kuprikov M. Y., Nizhenko A. A. Actuality of fairings (small bodies) modeling assignment with low level of radio cross section . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 170-174. This article depicts special features of fairing surfaces (small bodies) modeling process with applying of stealth technology in concept of modern stealth battlefield fighter with radio cross section limits. There is also shown contribution of such surfaces in total level of stealth aircraft radio cross section. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Tran N. D., Le T. H. Research deflected mode of the open cylindrical shell on the basis of the improved theory . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 175-183. In the framework of energy concerted theory of shells the open cylindrical shell under the local loadings is considered. The displacement and the components of deflected mode of a shell are expanded into polynomial series as functions of orthogonal coordinate. The basic equations in moving and edge conditions for various variants of fastening of edges of a shell are resulted. The operational method based on Laplace transform is applied to the equation decision. As a result half of edge statements of the problem are satisfied. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Martsinovich A. K. Economic efficiency of aviation industry enterprise insurance. Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 184-190. The problem of aviation industry enterprise insurance and its indicators are considered in this article. The review of possible methods of risk management is given. The impact of comprehensive insurance on the value of the enterprise is also analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stepanov V. D. Justification procedure of optimal funds allocation for aerial system development . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 191-200. Justification procedure of optimal funds allocation for aerial system development under financial deficiency is suggested. The approach is based on the development model allowing for conventionally logical constraints of its stages execution sequence and completeness. This enables justification of optimal funds allocation between development stages using the random searching method. The model of each development stage is based on marginal analysis procedures comparing conventionally fixed and conventionally varying costs in doing the job. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golovina A. A. Integrated system of staff training for aviation industry . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 201-205. In the article is considered the principles and features of HR Training system on the example of an aviation industry. Educational process is considered in the conditions of integration of efforts of the industry enterprises and the higher educational institutions providing training throughout all life cycle of the personnel from preparation of workers before training of the top skills. On the base of creation of the integrated system is the competency frameworks of industry workers which is transformed to educational competency-based frameworks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Latysheva V. V., Pochestnev A. А. Staffing in Russian aircraft industry in the beginning of 21st century . Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 206-211. The following problems are considered in this article: training of specialists for aircraft industry and the functions of management in attraction and adaptation of young specialists. Offered measures intend to increase quality of specialists training according to tasks of aircraft development and to form the system of strategic human resource management in aircraft industry | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kindinova V. V. Simulation, analysis and reengineering of operational processes of the warehouse aviation spare. Aerospace MAI Journal, 2012, vol. 19, no 3, pp. 212-220. The current version of the prototype simulation model operational process of the warehouse aviation spare at the stage of acceptance is presented, developed with the use of discrete event approach in the environment Anylogic6.0. The results of computer simulations to assess the quality of the existing technology acceptance were presented and analyzed. The possibilities of changing the process and improve its efficiency was investigate. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dunaev V. V., Gromov V. F., Makarov A. F., Eryomin M. V. Concerning support of durability to stress corrosion in mechanical joints with radial tension. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 5-10. This article covers the analysis of investigation results and hereby is recommended the selection of mechanical joint design technological properties values which are placed near the joint edges. Level of tension stress is considered to prevent the initiation of corrosion under the radial tension stress in the joint area. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitchenko Y. A. The models of first and second approximations for polyatomic gases flows. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 11-17. This article introduces the models conformable to Navier-Stokes-Fourier and Burnett approximations. Polyatomic molecules energy consider in two-temperature approximating. Shock wave profile validation test confirmed the validity of presented models. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kulkov V. M. Research of design parameters and the analysis of efficiency of application of the unified platforms with electric propulsion thrusters as a part of small spacecrafts. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 18-28. In work principles of development of small spacecrafts (SSC) with electric propulsion thrusters (EPT) are considered. Possible variants of application SSC with EPT are defined; recommendations about use EPT in structure SSC of various types are developed. With a view of expansion of possibilities and increase of efficiency of application SSC it is supposed to use power-thruster systems and modules, and also the unified platforms with electric propulsion thrusters and power supply systems on the basis of solar batteries. Methodical maintenance of designing of small spacecrafts with EPT is developed, mathematical models for design researches and the analysis of characteristics SSC with EPT on the basis of stationary plasma thrusters (SPT) and pulse plasma thrusters (PPT) and solar power unit are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Oleynikov I. I., Aksyonov O. Y., Pavlov V. P. The strategy of determination of the safe threshold probability of two space objects approach. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 29-34. The method of determination of the space object safe passing near the spacecraft threshold probability was suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidova N. S., Bochkov A. V. Self-organization of space-time structures transfer process in the support gas composition sorption system on the space objects . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 35-46. Unlike the traditional approach, the introduction of a sinusoidal velocity studies of transport processes of diffusion and convective components, thus allowing a control algorithm, as well as another approach to the selection of design parameters of units (length,diameter, width, etc.) and technological regimes are proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gnizdor R. Y., Mitrofanova O. A., Rumyantsev А. V. Investigation an influence of SPT magnetic field on efficiency of cathode-compensator operation. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 47-52. In this paper it is investigated an influence of magnetic field characteristics (parameters and topology) of SPT periphery using SPT-100 thruster model on efficiency of cathode-compensator operation while the cathode is translated. During investigations the comparison results of experiments and calculations suggests influence on efficiency of cathode-compensator operation not only magnetic field topology, but also magnetic field induction in cathode position. It is founded a correlation between magnetic field induction in cathode position and thruster performance. It is determined assumptive magnetic field induction less as 3 mTl in cathode position for maintenance of a high efficiency of cathode-compensator operation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Magerramova L. A. Application of hybrid blisks for gte turbines . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 53-64. Design expertise of hybrid blisks making from dissimilar materials, processing technique, advantages and disadvantages of manufacturing application for high temperature gas turbines engines and design problems is considerate. The blisk design studies well combining turbine wheel requirements of perspective GTE and making it possible to decreasing of wheel mass and increasing lifetime and gas dynamic efficiency of turbine are proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasich P. S., Dezhin D. S., Kovalev L. K., Kovalev K. L., Poltavez V. N. Superconducting electrical machines with permanent magnets and huge HTS element. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 65-76. Theoretical methods of calculating of two-dimensional magnetic fields, inductive parameters and output characteristics of the new type high-temperature superconducting (HTS) synchronous motors with a composite rotor. Are presented the composite rotor possesses the structure containing HTS flat elements, permanent magnets and ferromagnetic materials. The developed calculation model takes into account the concentrations and physical properties of these active rotor elements. The simulation results of experimental HTS motor with a composite rotor are presented. The application if new type HTS motor in different type of industrial high dynamic drivers are discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karpyshev A. V., Firsov V. P., Antyukhov I. V., Gorelov A. A. Heat transfer in high velocity gas-droplet jet and surface interaction at boiling. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 77-88. This paper represents the result of experimental heat exchange study at high velocity gas-droplet jet and hot surface interaction. The tests were conducted at water-and-air finely dispersed jet and copper calorimeter interaction. Droplet velocity in a stream varied 25 through 90 m/s and jet aperture angle varied 0 through 90°. It was found that a maximum heat flow value depending on jet velocity varied 5 through 8 MWt/m2. A surface cooling rate is more than 5-fold higher than a cooling rate in a great volume. At jet flowing onto the surface angle variation from 0 to 90° the density of a heat flow increases from 1.75 to 8 MWt/m2. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Timushev S. F., Fedoseev S. Y. Definition of the incipient cavitation number in a centrifugal pump by computational testing. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 89-93. 3D flow numerical modeling at the centrifugal pump inlet completed in flow rate range 0,61,3 from the BEP point. It is shown a possibility to define the incipient cavitation number in a centrifugal pump by CFD methods. Comparison with experimental data makes a conclusion that such a method can be used for improvement of cavitational quality of centrifugal pumps. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Potapov S. D., Perepelitsa D. D. Method of processing results of tests for sample on crack growth rate at test with constant amplitude loading . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 94-100. A method for processing the results of tests on samples of crack growth rate to determine the stable part of the kinetic diagram of obtaining the average values ??of fracture toughness properties in tests of several samples. Performed fractographic study of fracture surfaces of compact samples after the tests on the crack growth rate in order to confirm the accuracy of determining the upper limit of sustainable development of the crack area proposed method of processing the test results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voloschenko A. V., Gerasimov I. V., Oleshko V. S., Tkachenko D. P. The burns-control of compressor blade of gas turbine engine of device «Surface-11». Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 101-105. The problem occurrence of burns of titanium compressor blade are considered. The methods of burns-control is considered. The automated device of measurement of a contact potential difference is developed. The technique of not destroying burns-control of blade on change of electron work function , a contact potential difference measured by a method is developed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Andreev P. V., Eremin A. G., Fedorov M. Y. The use of composite and ceramic materials for constructing of high-load elements of nuclear space power systems . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 106-111. The use of composite and ceramic materials instead of metal ones in constructing of high-load elements of nuclear space power systems of greater capacity allows decreasing a mass of nuclear space power systems and increasing an operating temperature. Some technical and technological decisions along with the results of mechanical tests are presented in the paper. Issues requiring additional investigations are raised. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Avdeev A. V., Homjakov A. M. On the calculating and normalizing safety factors for different parts of the rocket engine . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 112-120. The new approach in methodology on the calculating and normalizing safety factors for different parts and knots of the engine, based on kinematic model of destruction is offered. As examples are defined a stock of a rotor on critical velocity, a stock on a carrying capacity of the impeller of the jet turbine and margin of safety of a bimetallic enclosure of chamber rocket engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lanevskiy Т. M., Leontiev M. K. Methodology of calculation OF CRACK growth in rotating details of turbine engines. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 121-133. The article presents the methodology of calculation of crack growth in rotating elements of turbine engines. The questions of choice of location of the initial defect size and shape of the crack are considered. Resource of HPC disc from titanium alloy is estimated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leontiev M. K., Snetkova E. I. Nonlinear models of rolling bearings in rotordynamics . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 134-145. The mathematical model of nonlinear rolling bearing with five degrees of freedom and the results of its application are considered. The model is used in dynamic analysis of complex rotor systems. It is based on the Hertz theory and takes into account bearing clearance, the number of rolling elements in contact, contact stiffness and also axial force acting on a bearing, contact angle. The results of static and dynamic analysis of a point rotor with nonlinear element are presented. This paper shows the significant influence of axial force acting on bearing and unbalanced rotor force on bearing stiffness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Nguyen N. M. Accuracy analysis of large unmanned aircraft motion using measuring-computational complex based on baro-inertial system . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 146-155. This paper proposes a more generic approach for flight motion controlling using measure information from baro-inertial system. In particular, we show how to estimate the individual and the accumulated influences of every measurement error on the accuracy of flight control, which cannot be completely compensated by an onboard computational algorithm. We create a program to simulate the flight motion under turbulent atmosphere in a non-inertial system of coordinates. Subsequently, a control system simulator is created based on an optimal controlling algorithm automatically looking for the requested motion trajectory and the controlling rules. This simulator also deploys an algorithm for aircraft stabilization and balancing. Finally, we create a simulation to estimate the measures from gyro-inertial system and barometer. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vovasov V. E. Realization of a relative observations method for attitude determination of highly dynamic objects with signals of global navigation satellite systems . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 156-165. In the article the expressions for single- and double-differenced pseudorange and pseudophase measurements for high dynamic objects are derived. Difference in these expressions is shown in comparison with classical expressions that suitable for low dynamic objects. Necessity and possibility of calculation the corrections for non-biased estimates of orientation angles for high dynamic objects are underlined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitin D. P. Investigation of methods for estimation of the orientation of the velocity vector of the moving navigation receiver . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 166-172. Considered methods of measuring the orientation of the velocity vector of motion standalone single-frequency receiver of navigation signals.Particular attention is paid to obtain estimates of the orientation of the velocity at low velocities of motion. We investigate a method to increase the accuracy of estimation of motion direction. Experimental data showing the precision characteristics of the method and its use. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tkachev A. B. Correlation properties of overlay coding in signals of global navigation satellite systems. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 173-176. Article is devoted for new formation methods of signals of the global navigating satellite systems that connected with application of overlay coding. Two possible variants of such application are considered: formation of identical and different overlay codes in the signals concerning with different satellites. Research of correlation properties of both variants of application of overlay codes on an example of the codes used in Galileo system is conducted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makarova S. M., Padalko S. N., Strogonova L. В., Terentiev M. N. Permanent 24-hour medical control of psychophysiological state and registration of spatial coordinates of cosmonauts with the use of Wireless Sensor Network. . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 177-181. Health control, valuation of physical capability and functional backup at all flight stages are the major part of health and efficiency support and spacecraft crew reliability. System for medical and psychological monitoring was developed at Moscow Aviation Institute to make wireless registration both electrophysiological signals and spatial coordinates of cosmonauts in airspace of spacecraft. For this purpose space station or interplanetary spacecraft are equipped with Wireless Sensor Network complex receiving and transmitting signal on onboard medical personal computer; at that all international standards of ethics for space experiments are observed. Received information allows to make true and efficient decision on correction of work-rest ratio, health support activities, and psychological support of crew. Successful completion of developed monitoring system allows to include it in system of medical control and in system of medical support of decision making in spacecraft medical backup. The proposed system is usable not only in space biology and medicine, but also in sports medicine for correction and optimization of work-out session. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanisov V. Y. New organisationally-economical approaches to pricing of development of air equipment of military assignment . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 182-191. Subject matter of given article is the background of new organizational-economic approaches to pricing development of new high technology aviation technics of military purpose (АТ ВН). It is shown, that existing organizational-economic approaches of customers to pricing development in modern organizational-economic conditions lead to low profitability (unprofitability) of development. New organizational-economic approaches to pricing the development, adequating by the stated author are offered to criterion to « a coordination of approaches « and a condition to « a normative correctness «, as well as methodical principles of their realization. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Urazova N. G., Pakhomov A. A. Classification of formation and development models of air transport industrys master links. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 192-197. Air transport industry is considered at the level of macro-economic framework within sector management defined its characteristics. The key sector elements having the greatest functional significance were determined. The classification of flows, characterized the modern air transport industry is represented. Here is proposed the classification of formation and development models of the main sector elements, depending on the goals, tasks and functional features. The most important determinants of the models type or the possibility for its change were identified. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Artamonov I. M. Application of deterministic factor analysis for quality management in infrastructure projects. Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 198-202. Analysis of quality model creation for infrastructure project was conducted. It was shown that such a model can be constructed using methods that are similar to deterministic factor analysis widely used in economic models. A method to structure a set of factors and to formthe final factor model was proposed. Major problems regarding practical application of the model were described and analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sidelnikov Y. V. Method of proportion for estimate labour-output ratio of innovation projects . Aerospace MAI Journal, 2012, vol. 19, no 2, pp. 203-209. The modification of estimate labour-output ratio method for innovation projects are for the first time suggested in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakhartchenko V. F., Targamadze R. C., Frolov E. A. Estimation of dynamic characteristics of low-sized UAV in longitudinal motion . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 5-11. There is given the approximate evaluation of longitudinal short period and phugoid motion frequencies of UAV characterizing by small wing loading and potentiality to carry out handoff type of take off. Such problem takes peace in automatisation of the vehicles provided the necessary level of flying qualities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lebedev G. N., Efimov A. V., Mikhailin D. A. Estimation of state vector for unmanned aerial vehicle (UAV) subject to non-linear characteristics of control object . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 12-16. In this article we consider new method for obtaining estimation of state vector for unmanned aerial vehicle (UAV) with use of identifier based on prediction operation from optimal Kalman filter. Estimation of non-observable UAV coordinates is being performed. Such coordinates are: flight-path angle, sideslip angle, vertical and horizontal wind angles. In order to exclude variable coefficients from equation for decreasing computation complexity we suggest to freeze coefficients which are most valuable for estimations of coordinates of Kalman gain matrix and set to zero its rest coefficients. Because of non-linear characteristics of elevator, rudder and aileron actuators we should take into consideration velocity and position constraints of these control surfaces. In this article we suggest the method which allows us to take these constraints in consideration. Also we present simulations of UAV landing and obtained results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gromov V. F., Makarov A. F., Ovsyannikov D. A. Influence of fitting on the operation of the hinge joint with plug. Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 17-23. There is given design model and by FEM was determined stress and strain state from the external load of plate with off-centered hole in which was installed free fit and with tension thin wall high tensile plug. On the example with explicit data of design technological parameters was determined the practicability of the plug installation in the hinge joint hole with radial tension, as under the compression and tension load the stress concentration decreases and improve the working conditions of such unit. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krahin O. I., Kuznecov A. P., Zenin V. A. Application of shape memory alloys in actuating units . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 24-34. Active elements made of shape memory alloys appear as the base elements of multifunctional actuating units, which are used in aerospace technologies, also in a radiolocation and special power plants transforming heat power to electricity. The detailed classification of actuating units is given, where these units are sorted by their ways of use. Then there are some results about researching characteristics of active elements, about their criteria of computation and valuing. Also the basic requirements are given for the special properties of the alloy and the active elements based on them. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Verbickij A. B., Rodionov G. L., Sidorenko A. S. Mathematical simulation vibration and dynamic states of an aircraft equipment structure in the conditions of their application . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 35-42. Outcomes of development of numerical model and data of a calculated estimation of characteristics of a dynamic state of an aircraft equipment structure, placed on a wing of the aviation carrier, at action of loadings from application of equipment are presented. On the basis of the developed finite-element model corresponding to features of a real structure of an outer wing, own forms and frequencies of a structure taking into account influence of stores are defined. Loadings from application of equipment are presented in a in the form of quasi-stationary random processes on the limited time section. Spectral density and levels of components vibration acceleration in places of a suspension bracket of equipment and zones of a structure with vibration maximum levels are defined. Estimations of the maximum values of displacements of equipment structure in the conditions of application for various loading cases and various variants of an arrangement of equipment are received. The work is executed at financial support of the RFBR (the project № 09-08-00519-а). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alekseenkov A. S., Naydenov A. V., Selivanov A. M. The development of autonomous aircraft electrohydraulic drivers . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 43-48. This article reviews current state and prospects of the standalone drives. Reviewed contains a new actuator scheme which allows to achieve a high dynamic performance in standalone mode. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zanegin S. Y., Kalugin V. N., Shishov D. M. Birotating electric airscrew drive for unmanned electric-powered aircraft . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 49-57. The article describes constructive differences between birotating electric motor and traditional electric motor, and its advantages as an airscrew drive. According to drive features and for using additional upward force caused by tangent component of airflow behind the airscrew, a special aircraft design was chosen. Description and results of coaxial airscrew propelling force (main and tangent) experiment, set on an aircraft model, are outlined. Aircraft conception using system approach was studied. Electric drive is used as load-bearing unit of the wing and three phase inverter schematics is designed to use rechargeable battery with maximum efficiency, according to the following aircraft conception. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M., Chapligin V. J. The study of fluid flow in an asymmetric hydraulic channels . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 58-64. The paper presents results of theoretical and experimental studies of fluid flowin asymmetric hydraulic channel (a.h.c.) under the influence of periodically bursty pressure source with varying steepness the fronts of increase and decrease of pressure who is inside a.h.c. Is presented scheme of the experimental setup. Experimentally established fact emergence directional fluid flow in a.h.c. The direction of fluid flow depends on the spectrum of pressure pulsations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bykov A. V. Means for computational and experimental investigations of aeroelastic stability of highly-maneuverable missiles . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 65-74. Hardware and software means for computational and experimental aeroelasticity investigations of «air-to-air» class missiles, such as ground vibration tests, flutter computations, aeroservoelasticity investigations are discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kondratieva L. A. Approximate analitic computation of the satellite stability periodic orbit . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 75-80. The method of approximate analytic limit cycles computation for the three dimension systems of ordinary differential equations realizes at example of satellite motion. The exactness estimates of obtained periodic solutions are giving in terms of relative residual. The orbits of consistent analytic approximations are building and their convergence to the searched stable limit cycle is demonstrating. The geometrical form of the given cycle turns out to be close to ellipse. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Avrashkov V. N., Gnesin E. M., Davidenko D. M., Meshcheriakov D. V., Chauveau C. . Measurements in an underexpanded hot free jet(PIV a method) . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 81-90. The objective of the work is to demonstrate the ability of the PIV technique to provide correct measurements of the velocity field in steady underexpanded hot free jet. A hot-gas generator capable to create jets with an initial diameter of 25 mm, total pressure up to 4 MPa, and total temperature up to 2200 K is presented together with the associated technique of stagnation conditions determination. The implementation of the PIV method is described paying attention to the choice of the PIV system components and to the seeding technique. Experimental results are presented on the observed jet structure and directly measured geometry of the Mach disk. The results on the velocity field are analyzed considering the effect of the kind of seeding particles as well as the jet stagnation conditions. Results from the experiment and numerical simulation are compared to validate the measurements of the velocity field. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leontiev M. K., Davydov A. V., Degtiarev S. A. Dynamics of rotors supported by magnetic bearings . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 91-101. The active magnetic bearings have many advantages compared to traditional bearing designs. However they require auxiliary bearings to prevent damages of AMD when the event power or a control loop failure. The design parameters of such supports have a significant influence on the behaviour of the rotor in dropdown situation. In this paper, common equations of rotor dynamics systems in nonlinear and nonstationary statement are studied. Nonlinear model of AMB, clearance and rolling bearing models are considering. Simulation results of rotor dropdown on auxiliary bearings and subsequent runout are shown with different types of auxiliary bearings. Shown, that in some cases, the rotor can perform dangerous motion for the construction backward whirl and/ or rolling motion. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Nguyen N. M. Accuracy analysis of large unmanned aircraft motion using measuring-computational complex based on baro-inertial system . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 102-114. This paper proposes a more generic approach for flight motion controlling using measure information from baro-inertial system. In particular, we show how to estimate the individual and the accumulated influences of every measurement error on the accuracy of flight control, which cannot be completely compensated by an onboard computational algorithm. We create a program to simulate the flight motion under turbulent atmosphere in a non-inertial system of coordinates. Subsequently, a control system simulator is created based on an optimal controlling algorithm automatically looking for the requested motion trajectory and the controlling rules. This simulator also deploys an algorithm for aircraft stabilization and balancing. Finally, we create a simulation to estimate the measures from gyro-inertial system and barometer. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chubarov O. U. The technique and software for the system of fire tests of liquid rocket engines of small thrust . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 115-122. The technique of diagnostics of the arisen failure condition is developed, based on the measured parameters of automated information-measuring and control system with application of secondary signs, as characteristics of malfunctions. The test complex is developed for working off of the offered technique, which subsystem of diagnostics allows to identify the arisen failure condition and to define a faulty measuring instrument or measuring instruments in case of their refusal. Results of experiments have confirmed working capacity of the developed technique. Results of experiments have confirmed working capacity of the developed technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ananenkov A. E., Nuzhdin V. M., Rastorguev V. V., Sokolov P. V., Schneider V. B. To the question of power line detection by the forward looking helicopter radar . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 123-127. The actual problem of safety maintenance for low-height helicopter flight by the means of the forward looking radar is considered. The restrictions caused by the physical nature of electromagnetic waves (EMW) scattering on a cylindrical surface are shown. Methods for the decision of a problem of electric transmission lines (ETL) detection are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Timoshenkov S. P., Kalugin V. V., Sokolov L. V., Parfenov N. M. Some of the research and development questions of the bonding the SOI structures. Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 128-137. Currently, the manufacturing of the SOI structures is promising for the development of MEMS devices, aviation pressure sensors, as well as the possibility of transition to nanotechnology. The use of SOI allows to reduce the size of elements to 50 nm, well as to ensure full electrical isolation of individual devices on a chip, utilized in on bord aviation MEMS. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Morgulis I. L. About calculation of probability of correct detection at the incoherent accumulation of amicably fluctuating signals . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 138-141. Correctness of the approximate formula for calculation of correct detection of amicably fluctuating targets at the incoherent simulation of N impulses with full correlation of fluctuations is being analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mikhaylov V. Y. The synthesis of a three-component composite codes subclass having extra large ensemble size. Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 142-148. An original construction of three-component composite codes, potentially having extra large ensemble size was proposed. The codes construction requires special algebraic relations between the code components, which serve as codes of maximum length. The basic characteristics of three-component composite codes correlation functions analysis was implemented. Completeness of a mathematical analysis allowed us to determine the necessary and sufficient conditions for the synthesis of codes required quality. The results are general for the codes subclass and are useful to build a powerful quasiorthogonal encoded signals ensembles required quality in the design of future asynchronous-address and command aerospace telecommunications systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Busurin V. I., Zwe N. Z. Simulation and compensation of temperature error of the pressure transducer based on optical tunneling . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 149-156. The paper considers the effect of unequivalent bending of receptive element of pressure transducer based on optical tunneling on his performances and a compensation of temperature error of the pressure transducer based on optical tunneling in order to obtain more reliable information (for example, about the pressure in combustion chambers of engines). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Le T. H. Strain-stress state of fringe effect on a cilindrical shell with variable thickness . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 157-162. Construction of fringe effect relationships for a cylindrical shell with thickness asymmetrically changing on length is considered. The method asymptotic integration of the differential equations of a three-dimensional problem of the theory of elasticity is applied. By means of special oblique-angled system of coordinates relationships similar to relationships of fringe effect for a cylindrical shell with a constant thickness are received. The basic differential equation of the fourth order with variable factors by to introductions of a new variable is led to a kind which common decision is expressed through modified functions Bessel. The example of calculation of the shell rigidly restrained on one edge is considered. Influence of lengths and thickness of a shell on components of tensely deformed condition analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Manturov D. V., Klochkov V. V. A system for forecasting and ensuring realizability of aircraft manufacturing enterprises production plans . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 163-172. Principles of construction and functioning of system for aircraft manufacturing enterprises production plans realizability evaluation and ensuring are suggested. Special attention is paid to organizational aspects of suggested procedures and methods implementation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov M. K. Application of the methods of financial and commercial payments when assessing the effectiveness of investments in aircraft the space experiment and the technical means for its implementation . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 173-179. The article presents some problems for ¬ economic structure a mathematical model to analyze the investment when you sel ect the aircraft the space experiment and the technical means for its implementation (EAC and TCP). Initial data for calculating the «real investment» (capital investments ¬ stresses) give information about the market, the company carrying out activities in the development and enforcement with respect to long-term holding ECAs and TCP. By specifying certain technical characteristics, the size of demand and prices, calculate the profitability of investing in the future, based on the planned level of profit. In this approach, there are constraints such as uncertainty will be ¬ ing cash receipts fr om circulation and the inability of the specific conditions ¬ loviyah sale of investments to track the profitability of its individual constituting the with . Discloses the use of methods of financial and commercial payments for improving calculation efficiency of investment and building valuation models. The sequence of model development is illustrated by hypothetical example the establishment and operation of «virtual» company to implement EAC and TCP. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fomkina V. I., Shatlovskaya K. V. Analysis and assessment of investment risks of aviation enterprises . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 180-187. For successful functioning the any aviation enterprise it is necessary to adopt new technologies. All it increases business, financial, technical, legal and other risks. Ability to properly manage them one of the important tasks of aviation enterprises. In carrying out its activities the enterprises may face risks associated with new projects. This may be risks associated with the failure of the project deadlines, lack of funding. It is important to understand the possible scenarios and be able to warn their negative effects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shemyakov A. O. Formation of the policy of information security of high school. Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 188-193. In this article the basic questions and features of construction of the high school information security system are considered. The basic stages of the information safety program (from risk assessments to cast and persons responsibility for safety of system) are revealed in the article. Also the tools of maintenance of physical and logic safety levels are analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Adamovich A. B. Space solar power station with the solar energy concentrator . Aerospace MAI Journal, 2012, vol. 19, no 1, pp. 194-195. The question on possibility of increase of efficiency of the solar silicon battery by filtering of not photoactive long-wave part of a solar spectrum is considered. The approach is specified at which having heated up batteries over the maximum temperature is excluded. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuprikov M. Y., Komissarov A. A., Roy R. I. Influence of requirements to the radar-tracking visibility level of the aircraft on its cost. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 5-11. This article is dedicated to the peculiarities of the maneuverable aircraft face design process under the cost limitation conditions. It shows the importance of the aircraft cost definition at the earlier stages of design process, ways of radio cross section lowering and their connection with parameters that determine its cost. The inverse task of design is shown in the area of the radar-tracking visibility. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilenko V. V., Goncharenko V. I., Shestakov P. S. Building a specialized cartographic projections and areas of the rech of ballistic targets. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 12-24. This article proposes a new approach to construction on the computer screen cartographic projections and interactive display regions the Earths surface, the various specialized contours and other facilities. On this basis, a program complex for the identification and visualization zones of reach of ballistic objects from the given coordinates of the points of the Earth. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Darnopykh V. V., Malyshev V. V. Optimization of satellite observation systems constellations on the basia of operative planning of their target functioning. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 25-34. The general methodology for optimization of satellite observation systems constellations on the basis of their target functioning operative planning is considered in the article. The general problem definition and mathematical statement are given. Methodica l approach for such problem solving and its main aspects are described. Several examples of model optimization problems are considered for constellations of 5 observation spacecrafts (SC) with project parameters of «Rapid Eye» system carrying out monitoring of local terrestrial objects during 3 or 4 days. The results are illustrated and discussed in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yakovlev A. А., Timushev S. F., Tsipenko A. V. Study of axial fan in the cae system "FlowWision". Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 35-38. Numerical study of axial fan in the software package FlowVision. An analysis of the possibilities of using different versions of a package to address the challenges the adequacy of the mathematical model and calculation methodology. Obtained results of numerical research, comparison with experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuz'michev R. V., Levin D. V., Misyutin R. Y., Zechikhin B. S. Higher power electric generators for aircraft application. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 39-46. Prospective higher power, high-voltage electric power generation systems for aircraft application, based on direct-drive synchronous generators with permanent magnet and electromagnetic excitation are considered. Higher power generator design schemes for variable frequency and direct current power supply systems are proposed and justified. Results of electromagnetic and structural studies of aircraft electric generators for prospective electric power supply systems are given. Comparative study of different designs of electric generators has been conducted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mitrokhov N. V. Experimental and calculation research of the coaxial heat exchanger characteristics for fuel heating for the research of combustion. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 47-52. The article is devoted to experimental investigation problems of wide range ramjets. Coaxial heat exchanger used for fuel heating during ramjet combustor studies is described. The process of heating fuel in the heat exchanger is considered. The results of calculation of the heat exchanger are compared with experiment data. A ramjet scheme with the stabilization of combustion by flat jets of heated gaseous fuels considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tretiyakova O. N., Shevchenko G. Y. Development of automation of technological process of laser controlled thermocracking of semiconductor and dielectric. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 53-67. The choice of technological modes for laser controlled thermocracking is relevant, but at the same time difficult multi-parameter task, which can be solved mainly through experimentation. The complexity of the problem is caused by the need to consider interrelation of parameters for laser radiation, the intensity and mode structure of laser radiation, the velocity of the beam and its shape, the orientation of the beam in space, and physical properties of semiconductor material etc. The developed software designed to manage the cutting of semiconductor and dielectric, using laser controlled thermocracking and automates the choice of modes of cutting laser controlled thermocracking. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tikhonov K. M., Tishkov V. V. Ground targets tracking software adjusted model development, taking into account human-operator possibility. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 68-77. It is considered the problem of Ground targets tracking software adjusted model development for linear moving carrier. Special attention was paid to human-operator capabilities in the software adjustment process. Parameters optimization of system maintenance was made during series of factor experiments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bolkunov A. I., Serdyukov A. I. Global navigation satellite systems effectiveness evaluation procedure. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 78-89. Proposed procedure for GNSS effectiveness evaluation of RNF and UPF шы based on three-level characteristics classification of RNF and UPF for most probable orbital constellations states with functioning and malfunctioning satellites and their drifts on latitudes. With the use of proposed characteristics classification GNSS effectiveness evaluation can be made considering all the peculiarities of RNF and UPF. This is demonstrated by carrying out RNF and UPF comparative analysis for different existing GNSS. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moiseev K. A., Panov Y. N. Special features of the dynamic behavior of nonliner systems with the finite number of degrees of freedom. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 90-95. Are given the results of investigating the system with two steps of freedom with the nonlinear elastic constraints, carried out on the basis of the energy method of determining the resonance frequencies and the being differed significantly from traditional ideas about the dynamic behavior of this type systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kudryavtseva I. A. The numerical model of incoming flow of plasma diagnostics problem near charged flat plate. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 96-101. In the article the plasma diagnostics problem by the flat probe located perpendicularly to incoming flow of strong ionized plasma is considered. The influence of external magnetic field is negligible. The mathematical model suggested in [1], includes the Fokker- Planck equation and the Poisson equation. In this article The numerical model of this problem solution based on the Monte-Carlo method is constructed. The results obtained illustrate dynamics of plasma parameters with directed plasma flow velocity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybin V. V. Simulating of fractional nonstationary control systems by the soectral method in engineering calculation software. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 102-118. Presently various mathematical computer-oriented systems and their extension packages are used for simulating of nonstationary control systems by the spectral method. Modern technologies such as the use of fractals in radio engineering, radiolocation, dynamical system theory generate the new electronic components. These component models contain fractional integral and differential operators. In this paper the spectral method is generalized for control systems which contain fractional integral and differential units. To simulate such systems the extension packages MLSY_SM, Spektr_SM+Simulink+Matlab, Spektr_SM+VisSim+Mathcad are modified. MLSY_SM extension package for Mathcad is applied to study the effect for the fractional order of the target coordinator of homing system under random noise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y., Pirumov U. G., Severina N. S. Testing of modeling technique of non - stationary flows of gas with shock and detonation waves. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 119-124. This research contains the results of testing of unique grid-characteristic method, meant for numerical research of non-stationary flows with physical and chemical transformations, as well as a description of test problems, which can be used by specialists in the field of modeling of chemically nonequilibrium flows. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Medvedskiy A. L., Tarlakovsky D. V. Non-stationary contact non deformable indenter with imperfections and elastic half-plane on a supersonic stage of introduction. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 125-132. In work the supersonic stage of interoperability absolutely rigid indenter and elastic isotropic homogeneous half-plane within the plane deformation of the theory of elasticity in conditions of rigid coupling contacting surfaces is considered. The problem of dynamics indenter is shown to initial problem Cauchy for system quasi linear the differential equations. Results of the solution to the problem about introduction in elastic half space indenter, having initial imperfections, and as consequence multiply area of contact are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ulyashin V. . Factors influencing development of civil aviation and its production. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 133-138. The article deals with the main factors and their elements which substantially influence the development of civil aviation aircraft and its production in the world. The article considers new technologies which can be used for civil aircraft production. Analysis of various types of production structures dealing with aviation aircraft is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panagushin V. P., Klonitskaya A. Y., Gusarova Y. V., Semenov P. N., Ivanisov V. Y. Establishment of an unprofitable type of activity and the reasons of crisis situations at the enterprises of aviation industry. Aerospace MAI Journal, 2011, vol. 18, no 6, pp. 139-149. The subject of this paper is to analyze the internal and external causes of loss of aviation industry. Ways of eliminating foreign losses and proposed economic mechanism against internal loss ratio. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baranov N. A., Vasilyev I. V., Poliansky V. V., Semenov I. M. Markov models to estimate safety performance functioning of complex aircraft systems . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 5-12. Approaches based on Markov processes to determine the cost of securing functioning of complex aircraft systems on the basis of economic effectiveness indicators and risk. We also consider the model to account for the possibility of identification of dangerous external influences, followed by counteraction in the event of a successful identification. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pichulin V. S., Smirnova G. G. A mathematical model of pilot's heat state adjustment. Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 13-22. The mathematical model of pilots heat state in the high-altitude flying suit is worked out. Mentioned model provides a way to determine an optimal temperature of air being forced into ventilation suit in dependence on pilots expenditure of energy. Obtained temperature provides the comfort pilots heat state. This model can be used in individual life support systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Degtyaryov S. A., Semyonov P. A., Borisov D. M., Rudenko A. M. Simulation of two-layer flow and heat transfer in the case of film cooling in hi-enthalpy streams . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 23-32. Increasing the rocket motor thrust specific impulse produces growth of the combustion products chamber temperature. For the purpose of perspective hi-energetic propellants implementing in space-rated SRM active thermal protection method was introduced and presents dual grain with extra low-temperature component. For the prediction of the efficiency of the film cooling produced by combustion products of the low-temperature propellant it was developed the method of conjugated calculation of the two-dimensional flow parameters fields, turbulent boundary layer characteristics, heat and mass transfer and thermal state of nozzle unit wall. Some experimental investigations of transonic nozzle unit part thermal state were fulfilled with variation of low-temperature fraction. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tumanov N. V., Lavrentyeva M. A., Cherkasova S. A. Residual life prediction of aero engine turbine disks based on calculation of low cycle fatigue crack stable growth . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 33-41. Technique for predicting residual life of aero engine turbine disks and determination of non-destructive inspection intervals has been developed which is based on the theory of low cycle fatigue crack stable growth. Results of verification and application of the technique are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ananyev A. V., Borisov D. M., Laptev I. V. Numerical simulation of supersonic hydrocarbon fuel combustion in complicated form channels . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 42-48. The hydrocarbon fuel combustion processes in supersonic chamber with gas generator are considered in this article. The mathematical model of such process is described. A set of calculations are fulfilled for different gas generators nozzle block configuration. The optimization of gas generators nozzle block was performed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Beklemishev N. N., Burago N. G., Zhuravlev A. A., Nikitin I. S. Aeroelastic analysis of the elements of compressor's structure. Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 49-61. Stress concentration zones near the GTE disk and blades junction are investigated numerically using various contact conditions. Aero-elastic effect of centrifugal and aerodynamic loads dependence on blade deformation is taken into account. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Agamirov V. L., Agamirov L. V., Vestyak V. A. Stabilization of dispersion of characteristics of fatigue properties of constructional materials at the statistical analysis of results of fatigue tests . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 62-71. The method of transformation the durability to destruction deals with the statistic analysis of the fatigue tests. This method stabilizes the features of the fatigue properties dispersion in connection with durability variation. It is especially actual in the process of extrapolation to the area of the long durability and the reasoning of the trusted areas for durability and for the limits of fatigue resistance.The method of the invariant statistic analysis enables to increase the accuracy of the definition of the tested characteristics and the limit of fatigue resistance. The amount of fatigue tests can be reduced as good as the total duration and cost cuts down, hence the efficiency of all the life-cycle stages of aviation products of rocket and space technology will increase. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tkachev A. B. New ways to increase noise stability of GNSS signals. Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 72-77. Various ways to increase noise stability of perspective navigating signals are considered. The analysis of new tendencies in development of navigating signals is carried out and possibility of increase of a noise stability at the expense of transfer of time label and its numbering to an overlay code in pilot signal components, and also at the expense of increase in ensemble used spreading codes is defined. The received results can be used in perspective signals of GLONASS system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Cherepanov V. V. The virtual scaner for research of the local spectral properties of high-porous materials . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 78-88. Methods and means of mathematical modeling of interaction of electromagnetic radiation with orthogonal representative elements of some high-porous heat-shielding materials are developed on the basis of the Mie theory and its consequences. Thanks to it possibilities of statistical modeling of materials by the Monte-Carlo method are essentially extended. There are a possibilities of definition such important for heat transfer the materials characteristics, as spectral absorption and scattering coefficients, spectral and spectral- transport coefficients of diffusion of radiation, scattering indicatrix, etc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidova N. S., Shangin I. A. The effect of hydrodynamical and electric parameters on processes of carry in the electrochemical concentrator oxygen of life support systems . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 89-96. The interconnected processes of transfer of mass, impulse and energy in the electrochemical concentrator of oxygen of the life support systems are considered. It is investigated of electrochemical system at formation no stationary fields of concentration, speeds, deformations, temperatures. The results of computational researches of mathematical model with nonlinear characteristics of a working environment are presented in the form of fields of concentration, speeds, deformations, temperature and normal and tangential components of a pressure. The profiles of tangential component of a pressure, having passed through peak in near-surface area, have character changing a direction. The profiles of concentration of components, speeds, temperature are changed most intensively in frontier area. The results of profiles of concentration and pressure define algorithm of control of operational-technological modes of the electrochemical life support systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Degtiariov A. V., Vdovin V. A. Program technologies for flexible adjustment of budgetary management system's information at the enterprises of the aviation industry . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 97-103. Provides software development experience, which dynamically changes and adapts depending on the specific organizational and economic characteristics of the enterprises and in advance of unknown algorithms calculate normative indicators. Provides an example of creating a software editor to configure the budget codebase and a fragment of the text of the program to calculate the expenditure side, implements technology software recognition, credibility, and interpretation of normative dependencies | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bulantseva L. V. The concept of choice of stakeholders in the strategy for the management of the communications innovation project enterprise on manufacture of aviation radiolocation systems . Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 104-115. This article presents an analysis of the conceptual framework of strategic management, with a view to lexical and structural positioning of key terms used in the strategic management of communications for the innovation project. Presented to the authors concept of selecting strategic partners for a specific project and justification of choice PR means to implement communications with them. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volodin A. A., Romanov S. N., Sorokin A. E. Risk-controlling tools of the business continuity management aviation industry. Aerospace MAI Journal, 2011, vol. 18, no 5, pp. 116-120. One of the necessary parts of the effective functioning of aviation industry is ability to manage the operation risks properly. In this paper a risk-controlling system which is supposed to protect the main products and services of an aviation company is proposed. This concept involves creating and maintaining an organizations ability to withstand incidents by using of risk-controlling tools in the management of business continuity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bodrishev A. V., Kuprikov M. Y. Choosing optimal layout solution proceeded from maintainability, interchangeability and quick-detachability requirements . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 20-26. The article is devoted to application of Kendall’s rank correlation in layout solution analysis for choosing optimal variant. Optimal variant is chosen on the basis of maximum layout density, revealed correlation dependence of such parameters as maintainability, interchangeability, quick-detachability of all object in the layout are taken into account. Obtained result is very important at initial stages of aircraft design. Developed calculating module is a part of a program for creating optimal layout solution with taking into consideration processing and operational factors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Osipov A. M., Kozorez D. A., Sypalo K. I. Solution to the problem of high-speed flying vehicle navigation. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 5-19. In this article the solution to the problem of high-speed flying vehicle navigation on a boost path using deep integration of data acquired from a strapdown inertial navigation system (SDINS), a multi-channel GNSS receiver, a radio altimeter and a vehicle-borne multi-channel observation system with synthetic aperture is proposed. The structure of a vehicle-borne integrated system, the mathematical models of sensors’ measurements, the data fusion algorithm and the results of the modeling of navigation using different classes of SDINS and under influence of jamming in a GNSS channel is also presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dunaev V. V., Gromov V. F., Makarov A. F., Eryomin M. V. Assembly tie change kinetics for bolted joint items with radial interference. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 27-37. In respect to bolted joints with radial interference and further gripping a relaxation of assembly tie is considered while dynamic variable loading. Effective increasing of structure endurance is attained by technological impact actions while bolting. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N., Borzykh S. V., Voronin V. V. The mathematical simulation of the spacecraft landing in the area of its contact with surface . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 38-46. The mathematical model of spacecraft dynamics motion in the landing surface is suggested. The spacecraft body and the elements of landing structure of the spacecraft are regarded as mechanical system of complex structure with internal connections. The algorithm of determination of the connection reactions is realized. The key parameters with affect to dynamics of the process are revealed, the safety of landing in the limits of the concrete restructions is investigated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev G. V., Kulkov V. M., Yegorov Y. G., Tuzikov S. A., Krajnov A. M. Design parameters and modes of movement of planet rovers in the conditions of the lowered gravitation research . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 47-53. The analysis of ways of movement of planet rovers at the lowered gravitation is presented. The concept of relocation of the cosmonaut, transportation of small-sized cargoes, towing of vehicles of the limited weight is developed. The mathematical model oj movement of the vehicle is developed and modes of movement of a planet rover are analyzed. Power advantages of spring movement for a certain range of level of gravitation and a vehicle design are shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko A. N., Kulikov N. I., Makarenko A. V., Sorokin A. E., Starovoytova N. P. Application of computer technologies at designing of specialized thyratron engines. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 54-64. On the basis of the complex approach questions of application of computer technologies and mathematical modeling at designing of electric drives for implanted system of auxiliary blood circulation and the professional electro-driven tool that allows to increase accuracy of calculations are considered, to apply optimization methods and to consider scalene correlations of a drive and system as a whole. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozlov V. I., Smirnov A. A. On the mechanism of electron transfer across non-uniform magnetic field. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 65-70. Electron motion in a non-uniform magnetic field is studied. It is shown that trajectory branches of cycloidal motion of an electron across magnetic induction vector are not symmetrical relative to the direction of its gradient. This allows more precise determination for the particle gradient drift direction. Mechanism of electron transfer across the magnetic induction vector and effects related to it and characterizing transfer dynamics are shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Agamirov V. L., Agamirov L. V., Vestyak V. A. A calculation method for obtaining quantiles of fatigue characteristics distribution of constructive elements . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 71-75. This article is dedicated to substantiation of lower guaranteed values of strength, durability and reliability of machines’ parts and constructive elements with respect to normal distribution law. The uses of existing tables of exact quantiles of non-central distribution as well as mathematical computation of those exact values are impeded by vast difficulties of such computations. This article presents an algorithm and implementation for computing exact values of quantiles. The presented model allows fast and accurate computing of quantiles of the non-central Student’s distribution, thus allowing quick computation of lower confidence intervals for strength, reliability and durability of constructive elements. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reviznikov D. L., Slastushenskiy Y. V. Applying fractional calculus in models of anomalous diffusion. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 76-82. Some problems of applying fractional calculus in models of anomalous diffusion are considered. High order finite-difference methods are presented for the anomalous diffusion equation with fractional derivatives in time and space. A random walk model for this equation is proposed. It is shown that results of numerical solution obtained with different methods are in good agreement. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bogdanov A. S., Shevtsov V. A. Locating subscribers by the signals of local radio-navigation network. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 83-86. The article deals with the principle and algorithm for determining the location for the signals of local radio navigation field in the coverage area of mobile radio communication, are the most typical errors affecting the accuracy of positioning. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerko S. A. Development of algorithms for determining the relative coordinates for moving objects based on the use of pseudophase measurement and their increments in GLONASS and GPS . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 87-92. This paper is devoted the development new algorithm for precise determination of the relative coordinates of moving objects with using the GNSS signals. As shown by the author, the existing algorithms are not effective when the number of visible satellite is less than 4-5. To delete these shortcomings, the author developed a new multi-step algorithm. Like the previous algorithms, new algorithm is based on measurements of ambiguous single/double carrier phase differences and unambiguous increments of these differences. The results obtained with using the simulation and real experiment showed that the new algorithm has the following properties. Firstly new algorithm has the same interval of time before the first decision is the same as in the previously known algorithms; secondly of the new algorithm loses in accuracy only slightly, but, most importantly, allows calculating assessments of the relative coordinates for moving objects with fewer visible satellites. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev O. V., Vishnyakov A. S., Khmarov I. М., Kondrashov N. G. Definition of spatial positions of flying machines under their two-dimensional dynamic images . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 93-101. In given article the method of definition of spatial positions of the flying machine on the basis of processing of its dynamic two-dimensional image from one chamber of an optical range is stated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panteleyev A. V., Metlitskaya D. V. Application of genetic algorithms to optimal control of the aircraft air-to-air flight range . Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 102-113. Proposed solution to the problem of optimal control of a flight range of aircraft air-to-air with the help of genetic algorithms for conditional global extremum with binary and real coding. Provide technical and mathematical formulation of the problem, propose an algorithm to solve this problem, based on which set up the appropriate software. Given an approximate solution to the problem of optimal control of the aircraft and compared the results with other methods, indicating the effectiveness of generated algorithms. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moiseev K. A., Panov Y. N. Method of evaluating the dynamics of cylindrical shells under the influence on them of the internal changing pressure. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 114-118. In the article is used original approach to a study of the dynamic behavior of the cylindrical shell, when it is not possible to use a condition of the orthogonality of the natural modes of vibration of shell for solving the partial differential equations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Piotuh D. S. Aviation company technological competence formalization method. Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 119-123. The article discusses the development of aviation companies to the level of technological competence centers. The formalization of the centers of technological competence can be based on common technology facilities of aircraft. A single object technology aircraft is a collection of intellectual property, designed for use in the manufacture of specific products.Technological competence Aviation Enterprise is a set of common technology object of aviation equipment, goodwill and human aviation company | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Badalova A. G., Panteleyev A. V. Software complex "Formation of fuzzy inference to find the level of risk in the enterprise aviation industry". Aerospace MAI Journal, 2011, vol. 18, no 4, pp. 124-136. The problem of finding the level of risk in the enterprise of aviation-industrial complex. To solve it, the authors proposed algorithm for forming fuzzy system, which is used to find the risk level on the grade on the basis of linguistic values of the probability of risk event, the probability of changes to the financial performance of the company after the risk event and the indicator of the relative changes in financial results. Examples are given to demonstrate the effectiveness of the system and appropriate software formed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volkov A. A. Unsteady modes behaviour of cabin air temperature control system. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 5-9. The article is dedicated to developing and analisis of mathemetical model for pressured cabin which is an object of temperature regulating system for regional aircraft. Article considers the impact of temperature sensor location onto unsteady processes in temperature regulating system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dolgov O. S., Sosedko A. A. Carrying out field and flight tests to verify the influence of moment-inertia layout parameters to the aircraft form . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 10-20. The paper describes alternative variants of tandem scheme aircrafts moment-inertia forms. Analyze the effect of moment-inertia characteristics changing to the formation of aircraft. The axial moments of inertia values for the existing aircraft was determined experimentally on the basis of field and flight tests, as well as using specialized software «МИФ». | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitchenko Y. A. Application of Navier—Stokes—Fourier model for the calculation of hypersonic flow past a thin plate . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 21-28. A problem is considered for a flow past an infinitely thin plate installed at a zero angle of attack in a hypersonic flow. The NSF model is accepted as a physico-mathematical flow model. Calculations are made with the use of McCormack explicit scheme and Thomas algorithm. Two methods of boundary conditions setting on a solid surface are considered. It is shown that in the strongly non-equilibrium flow region application of the NSF model results in qualitatively incorrect results when calculating normal voltages. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lebedev G. N., Tran N. D., Кitaiev A. N. Joint management and control of flight safety aircraft when they approach. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 29-35. We pose the problem of simultaneous control of the security counter and associated air traffic and management by automatic means. We propose a joint two-tier structure and control, by providing an adaptive adjustment of regulators necessary safety of flight when approaching aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Levochkin S. В. Methodology system synthesis of planning competitiveness new technician. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 36-44. This article presents the results of research of the author of LA konkurentosposobnosti. Examines the nature of the problem, its State and areas for improvement, most of which is to improve the quality of project development, estimated competitiveness LA. Proposed the concept and the framework competitiveness LA formation in draft form. The basic components of the methodology: the concept and structure of the system ensuring the competitiveness of LA (SOX LA); the system of knowledge, learning and their transformation to choose competitive advantages; analysis information for SOX; issues a decision. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovateva Y. S., Vorobiev A. G., Borovik I. N., Hohlov A. N., Kazennov I. S. Methane-oxygen liquid rocket engine of small thrust-development, design, tests and analysis of results . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 45-54. The technical paper about problem of development oxygen/methane liquid rocket engine of small thrust. The review is presented of actual state of problem. The analysis computational and the experimental data received during firing tests at the Beijing University of Astronautics and Aeronautic (BUAA) is carried out. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ponomarev A. A., Ponomarev N. B. About supersonic nozzle flow separation. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 55-64. In the article review of available information about flow separation in divergent part of jet supersonic axisymmetric nozzles is presented. Brief discription of methods of nozzle contours profiling and separation point situation predicting are given. Further ways of research in this field are proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. The influence of aluminium anode composition of the hydronic current source on its operation effectiveness in the mode of a hydrogen generator . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 65-73. The experimental volt-ampere and corrosion characteristics of A99 aluminium anodes, protector alloy АП4Н, and alloy of aluminium A995 and indium (0,6 mass. % In) have been obtained for the hydronic chemical current source (CCS) with smooth nickel cathode. The research has been carried out in alkaline electrolytes (4 М solution of NaOH, clear and with addition of 0,06 mol/l of Na2SnO3) and in salt electrolyte (4 М solution of NaCl). It was found out that hydrogen evolution speed in hydronic CCS with both alkaline-stannate and salt electrolytes is proportional to the current load that allows to regulate easily the capacity of hydronic CCS which operates as hydrogen generator for oxygen-hydrogen fuel cells of aviation, rocket and space equipment. Al-In alloy anodes are to be used in alkaline-stannate electrolyte, and the anodes of АП4Н protector alloy demonstrate better characteristics in neutral salt electrolyte. It was shown that short circuit current of the hydronic CCS is equal to 250300 А/m2 with salt electrolyte and increases up to 1500 А/ m2 with alkaline-stannate electrolyte. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kravchenko L. L., Okorokova N. S., Pushkin K. V., Sevruk S. D., Farmakovskaya A. A. The influence of cathode characteristics of the hydronic current source with aluminium anode on its operation effectiveness in the mode of a hydrogen generator . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 74-81. The polarization characteristics of smooth nickel cathodes, notched nickel mesh cathodes, the composite cathode made both from smooth nickel and notched nickel mesh, the electrodes made from notched nickel grid coated with NiPx catalyst and platinum foil electrodes in alkaline and neutral salt electrolytes have been studied for the hydronic chemical current source (CCS) with aluminium anode. It was shown that the use of the extended surface cathodes activated by NiPx catalyst that allow to increase the element voltage by more than 250 mV in alkaline electrolyte and about 180 mV in neutral electrolyte is the promising way to improve energy mass and overall characteristics of the hydronic CCS operating in the mode of hydrogen generator for oxygen-hydrogen fuel cells of aviation, rocket and space equipment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Magerramova L. A., Kratt E. P., Yacinsky V. V. Structural technological designing of bimetallic blisk for gas turbines. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 82-88. The structural of pilot one-piece bimetallic blisks for high temperature gas turbine with Ni-base super alloys blades and powder disk part are designed. The model equipment for connection uncooled and cooled blades with disk part by hot isostatic pressing technology (HIP) are offered. Plan of technological process is described. A strength calculation analysis of blisks is carried out. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dokuchaev A. E., Zinchuk A. A. Экспериментальное исследование применения тепловой трубы в газогенераторе. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 89-96. The article is devoted to researching of heat pipes application in the catalytic gas generator. The experimental gas generator with the liquid metal heat pipes is considered. The experimental research results of temperature distribution inside gas generator, as well as parameters of productivity are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pil'nikov A. V. Certain problem questions of high-power electric rocket propulsion system creation in Russia . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 97-103. One of available approaches to create high-power electric propulsion system (EPS) is shown. The possibility of using for this purpose of Hall thrusters with power of 2530 kW is fundamentally proven. The modular configuration of EPS structure with two simultaneously operated thrusters is proposed. Estimate calculations shows that high power Hall thruster modules usage allows to save about 20% of the EPS mass, even with the «cold» redundancy taken into account. To avoid the powerful and expensive vacuum test facilities developing the main testing of full-scale module is proposed to carry out directly in orbit, using the «Progress» cargo space ship. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraeva E. M. Energy parameters of high-speed pumps of low flow. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 104-109. The materials of balance testing of high-speed centrifugal pumps low flow rate are presented. Based on the analysis of studies have demonstrated the rational use of working wheel semi-open and open types, providing high value energy parameters of turbopump feed system of small consumption | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I., Belaja A. J. Maintenance of stability(immunity) of working process in combustion chamber liquid propellant rocket motors . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 110-115. Designing of modern liquid propellant rocket engines (LPRM) is impossible without generalization of an experimental material on instability of working process in the combustion chambers, accumulated as a result of firing tests of full-scale and modelling products. The present article is section of such generalization, in it (her) ways of elimination high-frequency oscillations of pressure of gas in combustion chambers LPRM and increases of a reserve of dynamic stability(immunity) of chambers are considered(examined) due to design features of mixing heads. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dvornichenko V. V., Burova A. Y. The deep testing aircraft by the methods of the mathematical statistics for increasing of their correspondence to the standards of the 1С АО . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 116-127. This article explores issue in-deep depth testing of aviation TURBOJET gas parameters to improve the quality and reliability, and airworthiness of the different types of aviation aero-engines, after their ground and flight-laboratory tests on factory hot stands in a serial production of these engines manufacturer of these products on the American example TURBOJETS J-75-P17, widely applicable to United States military aviation. In aviation practice have been analyzed the high representative statistical samples of measuring working standard parameters with the gas dynamic issue: for two-dimensions installed task, so as: Pr probability as the function of speed of rotation HPC n2; Pr= f(n2) and probability of viewing of the different intervals of the statistic samples of n2 of this parameter-control factor in FADEC/EEC of a aero-engines types, represented by a small parts of unity. Its realizing the normal law of distribution (Gauss-Laplace) of parameter control factor: or n2, or n1, or EPR. It is saving in flight about 3538% of the hours fuel mass consumption or are obtaining the gifts as the maximal flight route distance of the chosen aircraft type for the Long-Range Aircrafts, when the flights are going on for very long distance routes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gordeev V. A., Partola I. S., Firsov V. P. The estimate & test development of space launch vehicle Angara power plant. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 128-134. The article is devoted to task of cutting of space launch vehicle power plant experimental verification. The task is resolved by development of mathematic simulation complex which is tuned in by using experimental verification results. The task was resolved in joint works of the Khrunichev SRPC and the MAI named by S. Orjonikidze. The mathematic simulation complex was developed on base of space launch vehicle «Sojuz-2» power plant experimental verification and it was tuned in by using experimental verification results of LV Angara 3rd stage power plant. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leontiev M. K., Tereshko A. G. Investigation of characteristics of elastic rings mounted in rotor bearings of gas-turbine engines . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 135-146. The problem of determination of elastic ring stiffness mounted in gas-turbine engines bearings is considered. Analytical solutions give flexibility of elastic ring as curved beam with pinned-end supports. At once practice shows occurrence of abrasion on ring ledges during exploitation. It means the response of ring in rotor precession conditions is more complicated comparing with beam bending only. The FEM model of elastic ring placed between two stiff rings is prepared. Results of analysis show the large difference between flexibilities obtained by analytical solution and FEM statement when rings have contact interactions. The flexibility of elastic rings also strongly depends on assembling conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Selivanov A. M. The principle of combined speed control output unit hydraulic drive and its modern implementation . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 147-151. We propose a new combined a way to control speed of autonomous electrohydraulic actuators that use throttle and / or the electromotor speed control depending on the control signal. A general idea and the scheme of a combined control. Provides a schematic diagram drive that implements this method for aircraft control system and some results of studies of this. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Adaskin A. V., Isakova O. ., Sergeychik V. V., Filatov I. A., Zagrebin D. A. Multimodal means of functional diagnostics for civil aviation flight personnel. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 152-160. Reviewed the implementation results of a new generation of integrated rapid diagnostics of the condition of the flight personnel at the stages of medical examinations and operational control of dysfunctions of the cardiovascular system. The main directions of improving the means and methods for rapid diagnostics of the flight personnel cardiovascular system are defined. The results of the practical implementation of technology in the cardiovascular system multimodal research using system «Unimonex» are reviewed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Afonin A. A., . . An investigation of modulation gravimetric sensor with variable frequency modulation. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 161-169. The mathematical models of modulation gravimetric sensor (MGS), that was built on the basis of precision pendulum accelerometers, designed for use on a mobile foundation in variable acceleration projections are investigated. The modified algorithm MGS with variable current frequency modulation is analyzed. The efficiency of the algorithm in a mobile basis simulations are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chernomorskii A. I., Maximov V. N., Plekhanov V. E. Micromechanical attitude and heading reference system for uniaxial wheeled module. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 170-176. Algorithms and hardware of the MEMS-based attitude and heading reference system for two-wheeled module are developed. Kalman filter and quaternions are used to build integrated system. Modeling of algorithms was performed. Architecture for AHRS hardware was proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Neretin E. S. Software for airborne electronic devices test-system. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 177-184. Development of high-speed processing method, based on optical realization of a Hopfield neural network is discussed. Updating of one-dimensional and two-dimensional Hopfield models for possibility of its realization with optical methods. The automated complex is developed for working off the developed algorithms, allowing to realize a vector-matrix and matrix-matrix multiplication with optical methods. Results of experiments have confirmed working capacity of the developed method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pestunov V. A., Samsonovich S. L., Tchubikov V. N. Experimental research of a pressure stabilizer prototype. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 185-192. In current research we consider a prototype scheme of self-pressure stabilizer for aircraft, bench and main pipeline, based on the principle of quenching the perturbing pulses by themselves. We describe the bench, designed and constructed for experimental researches, methodology and analysis of experimental researches of prototypes. Recommendations for optimizing the parameters of its individual structural elements were developed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lalabekov V. I., Pestunov V. A., Samsonovich S. L. Working out of pressure stabilizer for aircraft, test bench, and technical systems. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 193-199. In the article the features of new type pressure stabilizer are considered, its operation principle, design realization, mathematic model, results of mathematic modeling and experimental researching the operation of the pressure stabilizer for aircraft, test bench and technical systems. The stabilizer is constructed on the base of using the energy of disturbance impulses itselves. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Busurin V. I., Khodin M. M., Knyaz V. A., Kaplansky G. A. Application of the scanning profilometer for measurement of aircraft engines details manufacturing precision . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 200-209. Paper contains a description of the precise scanning profilometer and software for its automation. Software for contours building and errors compensation is demonstrated. Form and algorithm for getting CAD-model of the body based on the Delaunay method from scanning results are suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Istomin B. A., Istomina T. V. System and technique for ROC-analysis of noise stabilities of ECG processing algorithms at monitoring of flight personnel . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 210-215. The system and technique of the ROC-analysis noise stability of electrocardiogram processing algorithms are considered at monitoring of flight personnel. The structure of system for an estimation of informative impulses detection efficiency and results of its researches are presented in a package of Matlab. Features and advantages of the user interface of system, and also prospect of its application in the course of preflight preparation are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyncherov K. T. Quality estimation of Production Control Automatic System. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 216-218. The article is devoted to the investigation of the quality of the Production Control Automatic System controllers. The neuronet processors applying non-positional deduction system have been used in the design of this cutting-edge system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyncherov K. T. Evaluation of the Production Control Automatic modular neuroprocessor reliability. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 219-221. The article is devoted to the estimation of the reliability of the advanced Production Control Automatic System, the neuronet processors of which function applying the non-positional deduction system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Annenkova I. U., Gribanov A. S. Direction finding of sources of radiosignals with pseudorandom frequency hopping. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 222-226. Differential-phase method of unambiguous definition of angular coordinates of several FHSS-signal sources and recovery of carrier frequencies of every emitting source, located in reconnaissance zone, are considered | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lobanov B. S., Bondarev Y. S., Kuzminykh A. S., Hlopov B. V. Method of controlling erasure information in information local networks. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 227-232. Considered methods to control erasing information from magnetic media by the visualization of magnetic fields. The method and device realizing secure erasure of information and provides the operational control of erasing the information in local communications networks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Podkorytov A. N. Precise Point Positioning in Global Navigation Satellite Systems Using Precise Ephemerides. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 233-239. The algorithm for precise point positioning technique in global navigation satellite systems using precise ephemerides is considered in the article. There are also results of experimental study of developed precise point positioning algorithm using precise ephemeris and clocks, and comparison results for international precise point positioning services. On basis of making research the conclusions about achieved point positioning accuracy are done and conditions for further algorithm improvements are formulated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gurevich M. S. Servo system with variable rotation frequency of coordinates . Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 240-250. By an example of the optical seeker it is illustrated that the parameters of servo system with variable rotation frequency of coordinates are connected, depending on the control system structure, either with the derivative of rotation angle only, or with derivative and the rotation angle itself. In the last case the dynamics and precision of the system change, in particular, in case of the single- channel control system with stabilization of rotation frequency . | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brekhov O. M., Thayk J. T. Productivity of tolerant distributed computing network with variable number of modules. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 251-265. The article discusses tolerant distributed computing network (DCN),which computing modules (CM) may be in one of three possible states: operable working, operable-controlled and inoperable (because of functional failure or unavailability of telecommunication). This assumes the ability to restore recovery efficiency CM. On the basis of the proposed model can be realized the assessment of the effectiveness of tolerant distributed computing network with variable number of CM. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ryabov A. A., Romanov V. I., Kukanov S. S., Shmotin Y. N., Chupin P. V. Dynamic deformation of cantilever plate under impact. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 266-273. Fan blade out of a gas-turbine jet engine leads to impact of the released blade to the engine case and the adjacent blade. Due to this impact the adjacent blade can be significantly deformed. Strains in some local zones of the blade can reach minimum elongation value of the blades material. Because of this fact, investigation of dynamic deformation of blades in high-velocity impact is very important problem [19]. Numerical simulations show that stress and strain distributions in the impacted blades are quite close to the ones distributions in impacted flat plates with selected sizes and orientation of the impact. The results of experimental and numerical investigations of the flat plates impact are presented in this paper. The erosion criterion, which can be used for the adjacent blade in the fan blade out analysis, is also presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Tran N. D. Local deflected mode of the cylindrical shell on the basis of the improved theory. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 274-286. In the framework of energy concerted theory of shells the cylindrical shell under the influence of some kinds of loadings is considered. By means of Laplace transform the decision of again formulated boundary problem about the deflected mode of a shell is constructed. The private decision for some kinds of local loading is received, namely: the distributed loading changing under any law along a longitudinal axis and under the cosine law in a district direction. As special loading cases action of the distributed loading of constant intensity and changing under the sine law on a part of an external surface of a shell is considered. On the basis of the equations received in work influence of a thickness of a shell, the sizes of a zone of local loading and character of external loading on normal pressure in a cover is investigated. Comparison of results of calculation of the normal tension received in given work and under the classical theory is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N., Borzykh S. V., Reshetnikov M. N. Simulation of relative motion of returned capsule and transporting vehicle during their separation. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 287-294. The equation system which describes the motion and interaction of returned capsule and cargo transport spacecraft with taking into consideration the specific mechanical connection between them. The safety of going out the capsule from the spacecraft is investigated. The safety is determined as the exclusion of the impacts in the relative motion process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N., Borzykh S. V., Iliasova I. R. Mathematical simulation of opening process of multy-element solar battery. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 295-302. The approach to simulating the dynamics of solar batteries in the process of opening with making use of Euler-Lagrange quasi- coordinate equations is suggested. The most often occurring in practice configuration of mechanical system is considered the central body (spacecraft body) and any number of solar battery «wings», which have the chain type construction. It is shown that the approach enables to write down the minimum dimension motion equation system. The concrete examples illustrate the potentials of the method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korovaytseva E. A., Fedotenkov G. V. Analytical method of calculating the steady nonlinear vibrations of discrete systems. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 303-309. Methodology of calculation of nonlinear discrete systems self-excited oscillation parameters is stated. Problems of investigation of stationary oscillations are one of the most pressing problems in the design, development and operation of a variety of technical systems. Critical importance they have for the liability structure of nodes and devices aerospace systems and power equipment. The methodology is tested in the most difficult conditions: in case of discrete systems with high quality of oscillation process with quality factor about 106 by example of electrical vibrations of two-circuit quartz oscillator. Numerical modeling is suggested for the control of results of using this methodology. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Bespalova V. E. Issues related to securing aircraft innovative projects with credits. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 310-314. The current state of the aircraft industry has been analyzed. Problems related to crediting of aircraft innovative projects have been highlighted. Issues related to securing aircraft innovative projects have been considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Badalova A. G., Shebarov A. I. The administration system for strategic innovative development of the aviation production systems. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 315-321. The article is intended to introduce the main aspects of the aviation production systems innovative development administration on the strategic level. The present article offers new strategies of enterprise innovative development on land, labor and capital markets. Each strategy is described by several parameters and criteria, which are also the measurers of the enterprise strategy effectiveness in exact innovative environment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kulikova A. N., Agapov S. A. Key performance indicators in corporate management of aviation enterprises. Aerospace MAI Journal, 2011, vol. 18, no 3, pp. 322-328. The article covers problems of effective corporate management of aviation enterprises based on budgeting. It discovers differences between budgeting and balance scorecard systems, definition of budgeting mechanism in corporate management of aviation enterprises on basis of key performance indicators. It describes classification of key performance indicators, gives sequences in selection of key performance indicators for Joint Stock Company «United Aircraft Corporation». | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Berns V. A., Prisekin V. L. Dynamic characteristics of the deflectable surface with shifted support. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 5-8. The experimental and calculated studies of the dynamic characteristics of the deflectable surfaces with the shifted support are carried out. It is found that the displacement of support leads to initiation of dry friction forces and as a result to the increase in the resonant speed and distortion of phase portraits of forced vibrations of surface. The results of the work can be used to identify the axis misalignment of the control elements supports according to the results of the resonance tests of aircrafts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brusov V. S., Petruchik V. P. Problems of investigation of flight aeromechanics for micro-UAVs. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 9-14. Some special features are discussed for aerodynamics and flight dynamics of very small unmanned aerial vehicles (micro-UAV) as well as evaluation problems for aerodynamic and dynamic characteristics associated with these features. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mynkin V. A., Obnosov B. V. Minimization of the regular component of "overshoot estimation» and the trajectory straightening in the problem to cross the two flying vehicles trajectories. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 15-25. Article is devoted to researches in the area of increase of accuracy of prompting of aviation means of defeat (AMD) a class «air-air». The basic direction of researches in this work is the account of the additional kinematic parameters accessible to measurement by homing head (HH) and anticipatory straightening of an AMD trajectory, by overlapping a vector of relative speed with a line of range on an initial site of boost. The considered methods allow to realize extremely close «parallel rapprochement» (PR) with the target and adaptability of prompting to any target maneuvers. Anticipatory straightening allows reduce flight time and optimize the overloads waste on the trajectories. Alongside with the account of additional parameters in function of prompting, it provides better prompting by the shortest way and reduction of a regular component of overshoot without increase of factor of proportional navigation value. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakhartchenko V. F., Targamadze R. C., Frolov E. A. Estimation of velocity characteristics of low-sized uav with electric engine. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 26-30. There is given the estimation the velocity interval of UAV horizontal flight for the given duration and the weight parameters of the vehicle. There is considered the UAV with handoff type of take off. After the electric engine with propeller start the initial velocity is created providing the necessary climb rate. The landing is carried out with help of parachute. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balyk V. M., Kulakova R. D., Khesin L. B. Modification of the design decisions in the statistical synthesis of the external characteristics of the aircraft. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 31-40. This paper investigates how to build and modify aerodynamic model unmanned aircraft based on flight tests. We give conditions for the stability of the design solution to the multicriteria and multi-factor uncertainties and statistical approach to the structural parametric synthesis of the aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kulkov V. M. Electrodynamics Tether System Design Parameter Analyze and Orbit Motion Control Modes Investigation. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 41-46. Low-orbit satellite with electrodynamics tether system (EDTS) motion control methods are presented. Efficiency EDTS using satellite maneuvering analyze is described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sedel'nikov A. V., Kazarina M. I. Influence of elastic elements temperature deformations on dynamics of the "nica-t" spacecraft. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 47-51. In work the problem of an estimation of the microaccelerations arising thanks to temperature deformations of the big elastic elements of space laboratory is considered. As model of an elastic element the plate is used homogeneous. Results of work can be used at modeling of a field of microaccelerations of the internal environment of space laboratory for the purpose of provision of requirements for successful realization of gravitatsionno-sensitive engineering procedures on its board. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Afanas'ev V. A., Chudetsky . M., Chudetckiy Y. V. The research of comets and asteroids based on the method of impact and explosive. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 52-55. The analysis of data gathered in the Deep Impact program showed that explosive impact is a promising method of space research. This method can be further improved by creating artificial particle cloud formations on the trajectory of asteroids and comets allowing multiple interactions instead of single. As a result of such explosive impact one can evaluate not only the structure and content of the space object but also interaction parameters related to destruction (erosion) of the space object. It is shown that generalized laws of impact cratering can be used to forecast the results of experiments in explosive impact. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Guseynov A. B. A methodology of management by the tests of flight vehicles. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 56-64. Basic principles of a system methodology of management by the tests of flight vehicles are expounded in the article. The structural and logical diagram of testing on all stages of development of flight vehicles is given. The tasks decided on the basic stages of tests are formed. Technique of determination of basic parameters and indexes of efficiency of network model of process of tests is given. The questions of optimization of allocation of the resources and estimation of risks of the tests are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Agul'nik A. В., Onishchik I. I., Htay T. M. The efficiency of combustion chamber work in the complex with turbojet engine. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 65-71. This is the calculation result of combustion efficiency and excess air coefficient at failure combustion in the combustor, working in turbojet structure. Parameters of engine working process and modes of its work were change. At calculations characteristics of compressors with various compression ratio and calculation programs of engine characteristics were used. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mitrofanov A. A. Improving the efficiency of axial compressors using control of the flow blades. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 72-82. The article deals with activities that enable both theoretically and practically to improve the qualitative and quantitative characteristics of axial compressors, power plants, in particular, air-breathing jet engines. Based on the significant progress in the field of materials science and technology of complex-shaped parts, are invited to apply to the design of axial compressors known and suggested involving the authors methods of control flow around the blades (OPS). The results of theoretical and experimental research of the author on this issue received in the MAI. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Toropov G. P., Khartov S. A. Model of plasma thruster jet propagation in vacuum chamber during testing considering electric field influence . Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 83-88. This paper contains the brief description of mathematical model of stationary plasma thruster jet propagation in vacuum chamber. The results of numerical analyses of gas distribution in the chamber during thruster operation, as well as calculation results of electric field potential generated by the thruster jet are presented. The estimation for distribution of charge exchange ions appearing in the vacuum chamber as the result of accelerated ions interaction with neutrals from chamber self-atmosphere is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shishkin A. G. Mathematical modeling of RF gas discharges in cylindrical chamber. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 89-97. In this paper the numerical study of RF gas discharge plasma behavior in cylindrical chamber is performed in the framework of 2D mathematical model. The model is based on the system of equations consisting of continuity and momentum equation for electrons and ions, electron energy equation and Poissons equation for electric field potential. By the numerical solution the profiles of main plasma parameters for hydrogen and helium are obtained. The developed model was applied for the analysis and prediction of parameters of plasma used for the sterilization of medical instruments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Borovik I. N. Development of optimal technical shape of liquid rocket engine of reusable the orbital transfer vehicle. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 98-107. In article the description of the concept of formation of technical shape of liquid rocket engine (LRE) the Orbital Transfer Vehicle (OTV) at stages of research works is resulted. On the basis of this concept the complex mathematical model «transport space system-OTV-LRE», intended for working out of preliminary technical shape OTV and a choice of optimum design parameters LRE by criteria of efficiency OTV of a various special-purpose designation is developed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bachev N. L., Matunin O. O., Kozlov A. A., Bacheva N. J. Working process with reburning of generating gas at supercritical parameters in the chamber of combustion of rocket engine on liquid fuel numerical modeling. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 108-116. The non-stationary two-dimensional equations reacting at supercritical parameters of «gaz+liquid drop» stream are considered. Results of thermal gas-dynamic calculation of parameters of working process in the chamber of combustion of rocket engine on liquid fuel with reburning of oxidizing generating gas are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A. Influence of the radial backlash on efficiency of axial turbines with the full supply with the rotating wheel with the bandage. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 117-122. The summary: results settlement, experimental researches of backlashes on EFFICIENCY of axial turbine stages Are resulted, the method of the account of losses from a radial backlash when losses basically are defined by size of leak of a working body through a radial backlash is given. Comparison of an offered method with known of the literature and with the spent experiments is spent. Accuracy of calculation is raised. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A. Researches of influence geometrical and gas dynamics parameters on expense factor in ring cracks . Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 123-131. Results of experimental, settlement research of influence geometrical, gas dynamics parameters on expense factor () in ring cracks (RT) are resulted. Are presented the theoretical formula of calculation in RT, and on the basis of experiments the empirical formula of the account of mutual influence of district speed, a radial backlash, pressure decline degree on in RT is received. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tumanov N. V. Physical and mechanical aspects of stable fatigue crack growth. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 132-136. Technique for modeling of stable fatigue crack growth has been developed which are based on the theory of local high-energy- type fracture mechanism acting at a crack front in the second stage of fatigue crack kinetics. The technique has been verified with the use of 3D finite element modeling and microfractographic reconstitution of fatigue crack growth. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fokin D. B., Lukovnikov A. V., Suntsov P. S. Features of mathematical modelling of dual-mode scramjet working process . Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 137-145. An approach to mathematical modelling of a powerplant with dual-mode scramjet and a statement of structure of main blocks, equations and assumptions of the software under development are described. Transition order from installed to uninstalled power- plant performances is presented, as well as of calculation results of speed-altitude performances with the use of considered mathematical model of dual-mode scramjet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gromov V. F., Makarov A. F., Ovsyannikov D. A. Deformation and tension in the elements of hinge joint while press-fitting of thin-wall high-strength plug. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 146-149. The Article contains a stress-strain analysis of swing latch elements, which is hardened by press fitting of high-strength thinwalled tap into the eye lug and performed the press fitting pin comparison. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lunev E. M. Improving the accuracy of uav navigation parameters during landing on the basis of photogrammetric measurements. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 150-159. This article explores the possibility of increasing the accuracy of the unmanned aircraft navigation parameters during landing based on photographic images of ground objects. Author proposes an algorithm for calculating the navigational parameters from the known coordinates of ground objects are displayed in the picture. Simulation results, which confirmed the possibility to increase the accuracy of the navigation parameters through the use of digital photographic images of the observed terrestrial object with known coordinates, are provided. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sharonov A. V., Novosyolov S. V. Wavelet-transform based aircraft image retrieval method. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 168-174. In this paper 2-d discrete wavelet-transform based method of optimal aircraft raster images retrieval is proposed. The fact the method provides required image search by wavelet-compressed image. This time costs of the algorithm on average less than 15% of the time cost of existing algorithms, and accuracy of your searches better at 13.5%. Besides wavelet-based image retrieval is invariant with the angle of aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Annenkov A. M. Telemetry signals error rate performance analysis . Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 175-179. Telemetry signals error rate comparative analysis was made. Dependence of error rate performance of frequency modulated signals with respect to modulation index and low pass filtering was researched. Error rate diagrams for various modulation methods were presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khramov A. A., Anickin N. А. A concurrency control protocol for mobile data access system which includes database management systems with SNAPSHOT isolation. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 180-185. We consider concurrency control issues in a Mobile Data Access System (MDAS), which is distributed heterogeneous database system with clients working in a mobile environment. Taking into consideration the formal model described in previous works, we propose a concurrency control protocol for an MDAS which includes both database management systems providing local serializability and those using Snapshot Isolation. We also consider the possibilities of using the results in aviation and space industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Tran N. D., Dang N. T. Operational method of research of the deflected mode of cylindrical shells on the basis of energy concerted theory. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 186-199. In the framework of energy concerted theory of shells the definition method of deflected mode of a cylindrical shell is considered. By means of Laplace transform the decision of the given problem is constructed, the number of any constants thus is twice reduced at integration of system of the differential equations of a problem. The private decision for various kinds of the local and distributed loadings is received. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Markina N. L., Reviznikov D. L. Numerical simulation of fluid flow in the presence of cavitation. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 200-210. A numerical simulation approach is discussed in regard to cavitating flow. Mathematical model is based on the NavierStokes equations, supplemented with transport equation containing source terms responsible for the interphase exchange. Modified PISO algorithm is used to couple the velocity, pressure and density fields. Fluid flow through a two-dimensional variable cross-section nozzle was simulated to verify the algorithm. Comparison of computational and experimental results for various cavitating regimes is presented. Fluctuation properties of flow hydrodynamic parameters are analysed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N. Refined model for calculation of stressed-strained state of three layered conic shells of rotation. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 211-218. The finite-element model for calculation of stressed-strained state of momentum bearing layers of three-layered conic shells is considered. Into approximation functions of displacements of finite elements of bearing layers are included displacements as hard whole (determinated by integration of proportions of Koshi at zero values of deformation) which leads to increasing of convergence speed of numerical results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ponomarev A. P., Bakulin V. N. Model of paraсhute opening with 2 degrees of freedom at axially symmetric potential flow. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 219-222. The model of parachute inflation, having two degrees of freedom and consisting of a circular cone canopy, a suspending lines and a dot weight is considered. The model can move vertically as the rigid whole and change a cone angle. Movement occurs in an ideal incompressible liquid, the flow around of the canopy is supposed potential. It is shown, that the Lagrange's second kind equations are equivalent to the condition of energy conservation and the equation for a pulse. Diagrams of the attached mass factors (attached moment of inertia) with reference to a deformable cone are pictured. Parameters of model movement in particular, size of stretching effort peak in suspending lines, and their dependence of initial conditions are determined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Luk'yanova A. A., Ryabishchuk I. V. The analysis of innovative potential of the defensive industrial complex enterprises on open joint stock company «Krasmash» example. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 223-229. In this article the analysis of a current situation of innovative potential of defense-industrial complex enterprises of on Open joint stock company «Krasmash» example is carried out. Its financial and personnel components are in more details considered. The basic reasons, making negative impact on innovative potential forming of defense-industrial complex enterprises are revealed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tariverdiev A. S. Special economic zones in russia: the history of creation and perspectives of development. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 230-234. The review of special economic zones phenomenon. Domestic experience concerning the functioning of special economic zones beginning from their first appearance in the USSR until the modern days. The possible prospects for the efficient performance of special economic zones in Russian Federation and the means necessary for achieving it. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Burdina A. A., Brusilovskaya E. A. The resource structure optimisation mechanism of aviation industrie's enterprise. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 235-241. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Razzhevajkin D. V. Enterprise innovation activity index in aviation industry. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 242-253. Current economical policy assumes the modernization of all economic components, through development of innovation sphere by high level of state financing. There is a range of evaluation and methodology questions in innovation process, which have no answers. This article contains the methodology of innovation activity measurement in enterprises of aviation industry through Enterprise Innovation Index determination. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pogosyans A. M. Experience of creating high quality and high technology product in the field of civil aircraft engineering. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 254-264. The article considers the complex of actions developed and introduced by ZAO «Sukhoi» into the process of creating and managing the quality of successful certification of the SuperJet-100 airplane. It also mentions the transfer of new high technologies and wide use of foreign colleagues knowledge and developed infrastructure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grigoriev E. V., Kozachenko D. A., Bodryshev V. V. The method of exploratory design. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 265-269. In this article is considered the possibility of using the methodology of exploratory design. Given the results of the analysis of maturity of the Russian enterprises of the aviation industry in regard to information. Shown the necessity of applying this methodology. Developed the models and methods on the example of cylindrical gear and the ways of developing software module. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozachenko D. A., Grigoriev E. V., Bodryshev V. V. Method of determining the complexity of the geometry of electronic product model. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 270-275. In this paper, a mathematical algorithm for calculating the single criterion of the geometry of the Electronic Macheta Products (EMP). Results of the analysis methods to create a solid model in the form of local criteria affecting the complexity of the geometry of the product. The mathematical apparatus designed to automatically calculate the single criterion of the geometry of parts and assemblies. This criterion will accelerate business processes Design and technological preparation of production (ETC) machine- building enterprises of the aviation industry, due to the automatic decision-making depending on the complexity of the geometry of the EMR. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Novikov I. S. Development of a science-methodological support for quality management system effectiveness and efficiency improvement in aviation industry organizations.. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 276-280. This article contains a description of Advanced Product Quality Planning (APQP) practical application currency and problems in quality management systems of aviation industry organizations. There are also results of authors work in this area and real statistics of implementation results in Russian industry organizations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Filatov I. A., Sergeychik V. V., Adaskin A. V., Zagrebin D. A. Development and clinical introduction of patient state remote monitoring system in online mode. Aerospace MAI Journal, 2011, vol. 18, no 2, pp. 160-167. Presented research results of hardware and software implementation for remote online checkup of civil aviation flight personnel in different medicals inspections. Methods of integrating remote systems, data acceptance, processing and transmitting in remote monitoring systems are elucidated. Facilities of using medical systems universal hub for integrating and synchronizing diagnostic information flow about operator state, worked in real time are discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishin V. M. Optimization of preference of one class of flying devices units under active separate loaded reservation. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 5-14. Faultness increase task is one of important problems of flying devises designers. Approximate analytical methods and exact numerical method of preference optimization of one class of flying devises units under active separate loaded reservation is considering in this working. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isaev V. K., Sorokin S. V. The methodological and theoretical basis for creation of Computer-Aided Weight Control System. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 15-20. This research is concerned with development of methodical and theoretical basis for Computer-Aided system of weight control. System analysis and formalization of application domain at the stage of R&D work are carried out. Search of suggestions for technical solutions of the system is performed. Main purpose is a formulation of recommendations for upgrading outdated industry CAD (computer-aided design) standards for aircraft construction to the level of contemporary international standards and experience. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Larina E. V., Kryukov I. A., Ivanov I. E. Influence of non-equilibrim modifications of two-equation turbulence models on numerical prediction of turbulence/shock interaction. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 21-26. The problem of homogenous isotropic turbulence interaction with steady normal shock is considered. Comparison of some variants of k- 8 - and к- CO -models is presented. Special attention was paid to influence different non-equilibrium modifications of the models on turbulence level increasing behind the shock. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sidelnikova O. V., Matveev Y. A. Complex analysis constructional and technical decisions of perspective flying machine subsystem. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 27-32. Experimental results for complex analysis of flying machine subsystems. Shows optimization of complex constructional and technical decisions of important subsystem elements and search algorithm for rational decisions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Knyazev I. A., Abashev V. M. Designing of construction REHF with transversal traction. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 33-38. Designing engine of hard fuel with transversal vector traction and investigating its intraballistic characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komkov V. A., Melnikov V. М., Kabdulin G. V., Bugaeva A. A. Designing of construction REHF with transversal traction. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 39-46. On the basis of the complex analysis of features of applied problems and is functional-technological possibilities of modern space technics the general concepts and creation stages, and also classification of basic constructive decisions of units of disclosing space frameless бескаркасных centrifugal designs for various applied problems are developed, ways of maintenance of high reliability oj their functioning and effective land working off are specified. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gordeev V. A., Timushev S. F., Firsov V. P., Tsipenko A. V., Yakovlev A. А. Design basics of aggregates disclosure of centrifugal space systems. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 47-53. There are some numerical simulation data of liquid flow in different construction tanks. Bundled software FlowVision is used. Are shown that it is necessary to include surface tension and wettability in mathematical model; it is necessary to ensure smooth acceleration from zero to known value, there is no set known value of acceleration and liquid level at the beginning of numerical simulation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shtyrlin A. F. Neutralizing of colloidal electroroket thruster charged particles beam. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 54-59. The one of possible mode of electroroket colloidal thruster charged particles beam neutralizing with the help of thermo emission cathode-neutralizer is analyzed. The structure, emission characteristics and neutralizing parameters for colloidal thruster module with thermo emission cathode done with 0.1 mm tungsten wire are described. The neutralizing parameters are: emission current -400 [l A, cathode bias voltage up to 100V, electron energetic cost is less than 500eV/el, the potential of isolated from ground thruster is - 18V. The cathode lifetime calculated under condition of its mass thermal evaporation (2000 degrees Celsius) without taking into account erosion by secondary ions not less than 6 years. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhdanov V. I., Kamalov R. N. Influence of gas cavity volume on pulsation frequency and amplitude in liquid swirl injectors, operating on self-pulsation regime. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 60-63. The article contains computational and experimental data on the influence of gas cavity volume in a hydraulic system on self-pulsation amplitude and frequency. Theoretical model of self-pulsation motion was experimentally validated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gopanchuk V. V., Nikulin N. M., Potapenko M. Y. Study of possibilities of optimization of magnetic systems of electric propulsion. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 64-74. Results of researches on optimizations of a configuration of magnetic systems of electric propulsion thrusters for the purpose oj increase of their efficiency by 10-15 %, and also for improvement of configuration of a magnetic field in a zone of output of the channel of plasma acceleration are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zvonarev S. L., Potapov A. Y. Vibrations diagnostic AI-222-25 jet engine in manufacturing experience for identifying bearing defects. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 75-80. This article is related to questions a bearing tone harmonics separating and identifications in vibrating signals of cases jet engines are considered. Results of experimental researches are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikolayev V. N. Temperature and air consumption definition optimization in the thermal conditions supporting system in the instrument bay of the photographic reconnaissance plane. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 92-98. The mathematical model of the thermal state of the bay is developed. The direct and inverse problems of heat exchange are solved. The confidence intervals of estimated parameters are determined. The values of temperature and air consumption in the thermal conditions supporting system in the venting heat-insulated instrument bay of the photographic reconnaissance plane are obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pichulin V. S., Eryukova T. A. Electroimpedance body composition analysis. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 99-104. The paper is devoted to bioimpedance measurement processing development basing on identification methods. There are formulation and solution for special biological tissue mass accounting problem in human body local region. This approach allows the investigation of special tissue types by a simple noninvasive technique in a space flight conditions. Furthermore, the tissue composition estimations are independent of the body hydration, so it is possible to determine wide range tissue types distribution in an object. Usually, such analyses are very difficult or impossible to make in a standard bioimpedance techniques process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Legostaev V. L. Software and algorithmic maintenance for MEASuReMENT complex of strapdown inertial navigation system for unmanned aerial vehicle. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 105-113. The paper presents the problem of software design for measurement complex of strapdown inertial navigation system. Operating systems algorithms for microcontroller 1892BM3T are given. Capabilities for measurement complex, merging strapdown inertial navigation and movement control system, are overviewed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Tomilin M. M. Research shields characteristics of flexible materials for purpose of their further application for shielding aerospace equipment against electromagnetic interference. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 121-125. The article describes results of researches characteristics different types flexible materials to detection possibility of their application for protection electronic elements and units of aerospace equipment from electromagnetic high frequency fields and electromagnetic interference arise from electrostatic discharges. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlova N. V., Vidov K. S. Information model making for the management of parameters choice in onboard equipment simulation. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 114-120. Tool means for the onboard equipment simulation and prototyping is the object of research. Information model making for the management of parameters choice in onboard equipment simulation is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Immoreev I. Y. Ultrawideband radars of small range for detection and definition of live objects' parametres. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 126-136. The basic features of ultrawideband radio systems - new and quickly developing information technology are considered. Possibilities of this technology on substantial increase of quality and increase in quantity of the transferred and accepted radio engineering information are shown. Examples of practical use of the ultrawideband radars developed by the Research Center oj Ultrawideband Technologies of the Moscow aviation institute, for detection of live objects and definition of their physiological and psychological parametres are made. Possibility of use of the received scientific results and technical decisions in various aviation and space appendices is shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Annenkova I. U. Methods of high-precision direction finding of satellite retransmitter using the emitting signal of the satellite. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 137-141. Method of improvement of the satellite system’s characteristics. Measurement ambiguity of the retransmitter location in the satellite communication systems («Milstar» and « Globalstar») was selected as the main object of research. The present paper gives the results of the research of the methods of resolving ambiguity problems with respect to structure of the satellite retransmitter signal («Milstar») and mode of operation with multiple subscribers on different frequencies of the «Globalstar» retransmitter. Numerical characteristics of satellite retransmitter location measurement error according to distance between two antennas of the analyser are obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev O. V., Khmarov I. М., Kondrashov N. G. Algorithms of allocation and recognition of aircrafts being on the earth by results of their space photographing. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 142-149. At the analysis of the data received as a result of photographing, of interest objects are allocated by means of brightness borders. The filtration of hindrances is made by means of the general and special geometrical filters. Thus the general geometrical filters on the area, cambers, to diameter and lengthening lead up an exponent of hindrances to an exponent of objects, and the filtration oj the remained hindrances and classification of objects are carried out by the special geometrical filters which are more precisely considering external forms of distinguished flying machines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ponomarev L. I., Vasin A. A., . ., Kapuskin S. A. Efficiency of using of high-temperature superconducting filters in high-frequency radio direction finders. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 150-158. Possibility of application of high-temperature superconducting (HTSC) filters in high-frequency (HF) radio direction finder is considered. Modeling of frequency responses of HTSC filters and direction finding accuracy is carried out using specific type oj filters. Requirements for the amplitude-frequency characteristics of these filters are imposed in order to reach high accuracy of direction finding. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khakhulin G. F., Novikov S. A., Posadsky A. I., Eskin V. I. The results of investigation of dynamic updating algorithm of the plan of supervision of mobile sea objects in the system of space monitoring. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 159-168. Problems of formation and dynamic updating of the plan of supervision of the mobile sea objects, time made on a set interval are considered. The data about results of survey of areas of possible position of these objects, arriving in the centre of reception and processing of the information of System is thus considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Merkishin G. V. Synthetic processing for structures image according to binary relations of shining points. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 169-174. It is regards the presenting of location coherent signals as the summer for space harmonics from radiating of shining points. Image of located object is formed as summer for binary relations among shining points pairs. It is regards synthetic processing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ignatskaya I. V. Interaction Graph Software Modeling and Support Conception. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 175-178. The article offers the new generalized approach towards the software modeling based on interaction graph which was developed by the author. This approach allows to design and to analyze software architecture according to given notation, to provide it’s maintenance and support. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Antufiyev B. A., Smiyan A. В. The elastic dinamical model of the mount of the airplane wing. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 179-184. The Problem of fundamental frequencies analysis and the problem of dynamical behavior of elastic extended body elasticly hung to console of the Airplane Wing which is making flexural-torsional oscillations were solved. Four modeling examples were considered | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zemskov A. V., Pukhly V. A., Pomeranskaya A. К., Tarlakovsky D. V. Upon computations of stressed-strained state of three-layers shells of variable rigidity . Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 185-193. Using E.I.Grigolyk’s line string hypothesis equations of equilibrium and natural boundary conditions were obtained for variable rigidity shells with rigid compressible aggregate. The solution for the boundary problem described by a system of partial differential equations is based on a Bubnov-Vlasov’s method synthesized with a modified successive approximations method. Computation results are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Tran N. D. Energy concerted the approach to research of elastic arbitrary shells. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 194-207. In the framework of energy concerted course of the theory of shells an arbitrary shell is considered as a three - dimensional body. The state equations of such body are presented in the form of three-dimensional equations of elasticity theory in the thriorthogonal coordinate system. Principle of virtual work is applied for extracting two-dimensional equations and getting edge conditions. The components of deflected mode of a shell are expanded into polynomial series as functions of orthogonal coordinate. As an example cylindrical shell is considered. For practical analysis of such shell polynomials of quite low power are used. Such approach allows us to consider transverse tension and shear deformations and self-balanced components of edge forces. To solve the desired boundary problem the displacements are expanded into trigonometrical series depending on circumferential coordinate. The influence of shell thickness on components of the deflected mode is investigated. Comparison with the results of classical theory is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenov P. N. The analysis of investment appeal of the enterprises of the aviation industry on the basis of a parameter of pure actives. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 208-212. One of key parameters of financial stability and investment appeal of the enterprises is the parameter of pure actives. Now pure actives of less size of the joint-stock (authorized) capital that is a sign of inadequancies have wide range of the enterprises of the aviation industry. In article the original structure of parameters on the basis of pure actives on which the analysis of investment appeal of the enterprises is spent is resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gavrilov D. G., Kornev Y. V., Mamonov S. V., Martirosov M. I. Nanoindentation of powdered lacquer coatings on metal samples. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. 81-91. The description of physical-mechanical properties on a nanometer scale makes possible to study the patterns of behavior oj surface layers and submicron volumes, clusters. This is especially important in the development of nanotechnology and as a consequence there is continuous downsizing by micromechanical and electrical components, film coatings and etc. Nanoindentation is the basic method which makes possible to test the physical-mechanical properties in nanoscale and determine up to twenty different properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gavrilov D. G., Kornev Y. V., Mamonov S. V., Martirosov M. I., Rabinsky L. N. Nanoindentation of powdered lacquer coatings on metal samples. Aerospace MAI Journal, 2011, vol. 18, no 1, pp. . The description of physical-mechanical properties on a nanometer scale makes possible to study the patterns of behavior oj surface layers and submicron volumes, clusters. This is especially important in the development of nanotechnology and as a consequence there is continuous downsizing by micromechanical and electrical components, film coatings and etc. Nanoindentation is the basic method which makes possible to test the physical-mechanical properties in nanoscale and determine up to twenty different properties | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ignatyev D. I. Application of artificial neural networks for simulation of delta wing aerodynamic characteristics . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 5-12. The conception of aerodynamic derivatives which is widely used for simulation of the unsteady aerodynamic characteristics does not provide the required precision of the results at high angles of attack due to the dynamical effects caused by the dynamics of flow separation and vortices breaking. A possibility of artificial neural networks application for simulation of the lift and pitch moment coefficients within the wide range of the angles of attack is demonstrated in the present work. A short definition of the artificial neural networks is presented. Given in the paper is the description of methods of the unstable aerodynamic characteristics mathematical simulation. Mathematical models describing the results of dynamical experiments with forced oscillations obtained at different frequencies are presented. Hysteresis of the lift and pitch moment coefficients is simulated on an example of a delta wing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinnikov V. V., Reviznikov D. L., Sposobin A. V. Application of precise and statistical approaches to numerical simulation of admixtire particle dynamics in heterogeneous flows . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 13-19. This work is concerned with comparison of two different discrete-element approaches to numerical simulation of collisional particle dynamics in a problem of a heterogeneous stream flowing around an obstacle. This paper presents authors’ method of direct numerical simulation with exact matching of real and model particles, solution of equations of motion and heat transfer for each particle, and calculation of particle collisions parameters based on approximation of trajectories. This approach requires significant computational cost, but takes into account all the possible collisions between particles in the flow and particle collisions with an obstacle. In this sense it is precise and is used as a benchmark for testing more economical statistical methods. Obtained results hold a high practical value for mathematical support of new technologies in airspace industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panchukov A. A. Maneuvering on the unlocked intermediate orbits. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 20-29. Examine possible schemes of functioning spacecraft for prime orbital flight in case of ascent to unlocked intermediate orbits. Propose variants of final orbital injection and single-turn maneuvers. State principles of autonomous real-time choise flight variant in case of contingency. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sviridov A. S. Orbit altitude choice principles for Earth surface observation space system on Sun-synchronous repeat ground track orbits . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 30-39. In the article there are stated the main concepts, characteristics and calculation principles of sun-synchronous repeat ground track orbits. Earth surface observation space system orbit altitude choice is considered as search of optimal by various criteria sun-synchronous repeat ground track orbits. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lozovsky V. V., . ., Rudenko N. V., Soloviev V. N. Mathematical model of a technical resource of the transformer in view of influence of electrodynamic forces on isolation . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 40-48. The service life of mains transformers specified in the specifications and technical documentation, pays off, proceeding from the certain normative conditions in which the transformer is maintained. However these conditions can differ from normative, that influences for the term of service of transformers. The account интенсивностей and current operating conditions which can be realized by means of a technique of the automated monitoring a technical condition, will allow to bring updatings in management of a technical condition of transformers. Existing mathematical models of an estimation of a technical condition of mains transformers possess a number of lacks that does a problem solved in clause actual. The mathematical model offered in clause can be used by development of a technique of the automated monitoring a technical condition of mains transformers and the means realizing the given technique, directed on increase of operational reliability of transformers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Potapov S. D., Perepelitsa D. D. Way of processing of results of tests of samples on crack-resisting with the purpose of definition of factors of the equation of Paris . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 49-54. In article the way of processing of results of tests of samples on growth rate of the crack is offered, allowing guaranteed to define without special fractography researches a site of steady growth of a crack. The way is tested at processing of results of tests of samples from nickel and titanic alloys and has shown that its application allows to raise reliability of results of processing essentially. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dudkin Y. P., Titov Y. К., Filippenkov R. G., Khizhnyakov Y. N. A fuzzy speed control of the free turbine gas turbine engine. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 55-60. The results of the development of the speed controller of a free turbine gas turbine engine, based on the principles of fuzzy control. The processes occurring in the system by mathematical simulation using Matlab-Simulink. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Inozemtsev A. A., Evgrashin Y. В., Ovchinnikov A. . Probabilistic model of isoentropic flow in aircraft gas turbine engine. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 61-65. This paper considers various probabilistic models of isoentropic flow. The study found that the only model that does not contain internal contradictions, is one in which it is assumed that the variation of the dimensionless velocity equal to zero. This technique can be applied in the design of various components of gas turbine engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ponomarev A. A., Ponomarev N. B. Investigation of specific impulse losses due to irregularity of combustion products distribution . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 66-71. In the article the problem of predicting of liquid rocket engine specific impulse is discussed. Brief discription of the structure oj specific impulse losses is given. Losses due to irregularity of combustion products distribution are given special attention. New method of calculating such losses on the basis of experimental data and results obtained with the aid of this method are shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y. Problem of Riman in detonating gas. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 72-79. Results of the decision of the Riman problems on border inert gas - a gas mixture are resulted. As inert gas helium, as a gas mixture - the hydrogen- oxygen explosion mixture diluted with argon was considered. The problem dared in «frozen», «equilibrium» and «nonequilibrium» statements. It is received that the parameters of the stationary recompressed detonation wave received in non-stationary nonequilibrium statement coincide with the corresponding parameters received at the decision of an automodelling problem about disintegration of rupture in «equilibrium» statement. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Timokhin M. U., Ivanov I. E., Kryukov I. A. Application of rl3 moment equations for modeling Shockwave gas-dynamics flows. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 80-87. The article is devoted to numerical method of solution of Grad’s moment equations [1] and regularized Grad’s moment equations [2] for two-dimensional flows. The numerical method is formulated as an extension of explicit high order Godunov method [7] with linear flow parameter reconstruction. Conservative variable fluxes on computational cell edges are evaluated with approximate HLL Riemann solver. Modified explicit/implicit Runge-Kutta method of second order of accuracy is used for time approximation. Some examples of shock flow calculation are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makarenko A. V. The comparative analysis of fuel mixes for the independent drive of the control system of the planning parachute . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 88-93. On the basis of the complex approach research energy-mass characteristics of various types of fuel mixes for an independent watching drive on the basis of an internal combustion engine for the decision of problems of management is carried out by a cargo planning parachute, their comparative analysis with traditional primary energy sources is given and recommendations for choice optimum recipes of fuel mixes are offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golovin D. L. Quality maintenance at technological designing of a difficult high technology product. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 94-99. In the early phases of a project a product is just an idea (a product concept) described by its expected functionality and features. The definition of product in this case would be the idea or concept of a thing that may be designed and produced or manufacture to meet the customer and manufacture requirements. From the design process perspective, later in the life cycle, a product would be the design of a thing that may be produced or manufacture. So we have models above reflect different life cycle views of a product, the as-required, the as-designed and the as-built, as-used views | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Homjakov A. M. Kinematic model of destruction the engine. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 100-108. In article the new methodology in definition of safety factors of details and engine knots is offered. The kinematic model oj destruction is considered and on its basis the fundamental theorem of the theory of power designing is declared. The equation oj existence of knots and units in connection with the decision of static and dynamic problems and problems about stability loss is formed. For the first time definition of concepts is made: durabilities of knot, durability of the unit, durability of the engine. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volkovsky A. S., Vazhenin N. A. Noise stability of the digital radio telecommunication systems at joint influence of noise and pulse interferences . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 109-119. The generalization of analytical Middlton’s model allowing to investigate a noise stability of perspective command radio links of deep space at influence of own radiation of electric rocket propulsions is considered. On the basis of the developed analytical models a noise stability of digital radio communication systems with a binary phase shift keying is carried out. Comparison of results of analytical calculations and simulation is resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yudin V. N., Nosov N. V. Noise immunity of satellite radio navigation system relatively to the intrasystem noise . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 120-124. User equipment (UE) noise immunity of radio satellite navigation system has been assessed in relation to the intrasystem noise. It has been illustrated that intrasystem noise is not more dangerous for UE in comparison with the jamming type «noise». | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Boriskin A. D. Restoring full phase measurements of Global Navigation Satellite System from their fractional parts . Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 125-128. This article is devoted to compression of phase observation of Global Navigation Satellite System. The specific of these observations (under certain conditions) make it possible to sent them by modulo of 1 cycle, and then on receiving side restore full phase measurement. In result author reduce in 3 times the size of phase correction (from 24 bit to 8 bit) without any loss in final performance of differential system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khramov A. A., Anickin N. А. Concurrency control problems in mobile data access systems and methods for their solving. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 129-138. We consider a mobile data access system as a form of a distributed database. We describe a formal model of the system. Concurrency control problems arising in such systems are shown using this model. Methods for solving the problems described are also examined. These methods can be applied | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kossov P. V., Mikheev S. M. Design of electronic video stabilization algorithm based on a Digital Signal Processor. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 139-143. The paper provides justification for the use of electronic video stabilization as one of operating modes of an opto-electronic search-detection station. Electronic video stabilization algorithm has been designed and implemented on the base of Digital Signal Processor. Throughput capacity of the suggested algorithm has been evaluated. Implemented algorithm has proved to be effective. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brekhov O. M., Krapivniy A. . Universal onboard platform. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 144-151. The problem of construction of a universal onboard platform (UOP) a small flying apparatus is considered. The evaluate oj computing structures UOP is executed, the operating system concept is defined | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vestyak V. A., Zemskov A. V., Fedotenkov G. V. Weak irregular heating of unconfined layered plate. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 152-158. A layered composite plate heating problem is examined. Initial thermoelasticity equations with fast oscillating quotients are transformed into zeroth-order approximation equations via asymptotic averaging procedure. Boundary conditions are irregular, irregularity representing uneven surface heating of the plate. To obtain a solution an asymptotic variable separation procedure is used. The procedure is based upon introduction of several scaled variables. It allows us to solve the problem assuming that heating unevenness is weak. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bezrodnykh I. P., Ershova Y. A., Ladzina D. E., Chechikov Y. B. Periodic components of electron stream in external magnetosphere. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 159-162. Methods of the spectral analysis of time numbers of experimental data of speed of a solar wind, intensity of streams relativistic electrons in an external radiating belt of the Earth and streams getting enough sleep electrons receive the result confirming dependence of dynamics relativistic electrons of an external radiating belt of the Earth from dynamics of recurrent high-speed streams of a solar wind. At increase in the frequency permission it was revealed that in intensity of streams relativistic electrons in a geostationary orbit from 1986 for 1995 there were two periodic components with the periods nearby 26 and 30 days. On the basis of it the conclusion has been drawn that the strongest influence on dynamics of streams relativistic electrons in an external radiating belt of the Earth is rendered by solar activity on two various heliolatitude. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abgarian K. К., Bazhanov D. I., Mutigullin I. V. Application of the high-performance computing for the study of electronic and structural properties of InN and GaN thin films on Si(lll) substrate. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 163-166. In this work ab initio study of atomic and electronic structure of InN and GaN on Si(lll) substrate was carried out in the framework of the Density functional theory. Obtained results are able to describe the structure of InN/Si interface on the atomic level and the impact of tensile and compressive strain on the width of the band gap of InN and GaN. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Artyemenko . V. The account of results of the comparative rating estimation of the financial condition of the enterprise at formirova-nii the initial prices of the state contracts. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 167-172. In article the technique complex comparative rating otsen e financial conditions of the enterprise of the oboronno-industrial complex which is taking part in deliveries of the aviation military-oriented technics or its components is considered. On the basis oj this technique the author offers the approach to formation of the initial price go-sudarstvennogo the contract with the account of its rating estimation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Klochkov Y. S. Evaluation of quality management systems processes with account taken of concealed consumer. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 173-180. In the present article classification of consumers is suggested with consideration of concealed consumer and characteristic oj latency. Evaluation procedures for the life cycle processes quality and for the role of estimating procedures subject are defined. Time diagram of the process quality estimating by its subjects is suggested. Analysis toolkit for the process owner’s requirements is developed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churkin E. M., Bokarev P. A., Chernov V. M., Serpichev A. I. Information and advising system as innovation activity unit of the aerospace industry enterprises. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 181-185. For the project of automation of aerospace enterprises is described automated management technique. It’s based on matching different information and advising systems | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Burdina A. A., Brusilovskaya E. A. The using of intellectual capital in the management of aviation organization. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 186-194. The effective management of intellectual capital of aviation organization is the key factor of competitive ability and effectiveness in the contemporary economic situation. But there are intellectual capital’s peculiar characteristic and almost no approaches to management in practice. So the management of intellectual capital is become difficult by these reasons. The technology of intellectual capital management on the intellectual capital navigator base is considered in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fomkina V. I., Moskvicheva N. V. Questions of application of the value approach as the effective way of management at the aviation enterprises. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 195-199. The article deals with issues relevant to determination of the market value of an enterprise as basic criteria of management efficiency. These issues are of special significance for enterprises of the aviation industry. The integration process started in 2006 has necessitated reorganization and restructuring of the enterprises affiliated with the united aircraft building corporation. The cost approach creates an mechanism of managing investment and innovation projects universal for all business units, branches and functional subdivisions, enabling to significantly increase the efficiency of joint activities and to set up an integrated management system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tarasova E. V., Sapfirov A. A. Intangible asset of aircraft company and in it's financial statement. Aerospace MAI Journal, 2010, vol. 17, no 6, pp. 200-204. This article related to reflection of revaluated intangible assets in the financial statement of the company. There is shown, that the improvement of some financical indicators of the avia corporation «Irkut», taken as example, has lead to the growth of investment appeal of the interprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rakov D. L., Thorbeck J. . Lift control system for ballastfree balloons. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 12-16. In article various principles of lift control for balloons are considered. Possibility of application of an active control system is investigated by an aerostatic power. The principle of a volume and pressure variation at balloon flight is investigated. As a result oj structurally-parametrical synthesis and numerical calculation conclusions are drawn on features of the offered schemes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Reznikov Vladimir M., V. M. Use of aeronautic devices for decrease in risks of extreme situations. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 17-23. In article use of aeronautic devices (ВПА) - dirigible balloons, balloons - is consideredfexamined} at monitoring ЧС and conducting rescue and regenerative works. As efficiency of monitoring efficiency of reception of the information is consideredfexamined} and itsfher} insufficiency is shown at grouping KA less than 2 tens. The estimation aprioristic and апостериорной is offered to probability of the short-term forecast of earthquakes. Advantage ВПА before KA as well is shown due to decreasefreduction} in height in 20 - 30 times and due to maintenance use of a radar. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voronich I. V., Kolchev S. A., Konshin V. N., Tkachenko V. V. On small-sized unmanned aircraft for area monitoring. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 24-33. Purpose of present work is to form requirements for small-sized unmanned aircraft suitable for extensive radiation and ecological area monitoring in the field. Paper includes short review of designs, aerodynamic and technical characteristics of small- and middle-sized aircrafts for generalization of research results. Aspects of realization of such aircrafts in aerodynamical shapes, propulsion unit, and service load are considered. Prototype and ways of its modification to meet formulated requirements are defined. Fundamentals of computational technique for computational-experimental research are discussed. Example of technique application is given | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sidorenko A. S. Dynamic state of a helicopter's structure at non-stationary movement of the landing spot . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 34-42. The procedure and outcomes of development of a numerical model and data of computational researches of a dynamic state oj a helicopter’s load-carrying structure and aggregate at its placing on a mobile landing spot are presented. Action of transient поп -stationary kinematic disturbance on a helicopter’s structure connected to a mobile platform by one-sided elastic links (mooring elements) is considered. The kinematic disturbance, arising at an emergency condition, is transferred to a structure through landing gear and mooring elements. The problem about non-stationary movement is solved with use of a finite elements method on which basis models of a load-carrying structure and nonlinear-elastic mechanisms of landing gear are solved. Time dependences of displacements, speeds and accelerations in various points of the helicopter’s structure are obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dolgov O. S., Kuprikov M. Y., Ripetskiy A. V. Predesign geometric synthesis characteristics for long range great seat capacity aircraft layout . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 43-48. New approach to layout predesign for perspective long range aircraft of great seat capacity is presented herein with regard to relevant range of application. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shydakov V. I. Disc vortex theory of main rotor at axial blowing with account nonlinearity of vortex trace . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 49-56. The non-linear disc vortex theory of main rotor is submitted for hovering and vertical takeoff of helicopter. Integral equations were derived. These equations are used for calculation of the field of induced velocities in the main rotor disk plane and in the main rotor slipstream, when the specific rotor load distribution is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shydakov V. I., Zavalov O. A. Investigation of parameters of vortex wake of helicopter main rotor at axial blowing on the base of non-linear disc theory . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 57-64. The method of calculation of field of induced velocities in the main rotor disk plane and in the main rotor slipstream the based on non-linear disc theory is submitted in the paper. The calculated plot of the streamline of air jet and result of investigation oj parameters of the streamline of air jet at hovering and vertical takeoff of helicopter are submitted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Syrov A. S., Sokolov V. N., Ejov V. ., Bocharov M. . Terminal targeting for upper-stage rocket vehicle "Breeze-M". Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 65-68. Distinctive features of Breeze-M as a controlled object for flight control system and design philosophy of terminal control for launching it on specified orbit are examined in this work. Such control system is realized on periodic solution of boundary-value problem with numerical and analytical procedures. The applied algorithm provides high methodical precision. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
На S. . Unsteady simulation of gas separation in gravitational field. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 69-76. The unsteady process of gas separation under the effect of gravitation and diffusion was investigated. To solve Navier-Stokes equations with multiple molecules Eulerian model is applied. It is shown, that it is possible to calculate falling velocity of light¬weight molecules in mixing gas | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Averin S. V., Anisimova T. V., Danilina A. N., Kryuchkov V. V. Synthesis of multilevel inverter output voltages with improved harmonic content for flying vehicle power supply systems . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 77-84. The problem of producing multilevel waveforms using general Fourier series is presented. Such technique can be applied to power electronics as a tool for producing stepped waveforms approximating sinusoidal waveform. Such approach to the synthesis oj AC voltages is based on Fourier series of orthogonal functions set. Using presented analytical methods and expressions, one can determine optimal parameters of voltages ensuring minimal harmonic content. Presented mathematical tool is very useful when designing structures and control algorithms for converters with multilevel output waveforms. Simulation results confirming theoretical data | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gubertov A. M., Desyatov A. V., Golovin Y. ., Vezhnevets P. D., Valiullin Faat H F. F., Lukoyanov Y. M., Sobolev V. . Research of thermal decomposition of hydrocarbon fuel at the stream in heating pipes. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 85-95. Experimental researches of hydrocarbon fuels stream in a modeling pipe at supercritical pressures have been realized. The common regularities of deposition on the pipe walls have been explored. Calculation of temperatures profile on the length of the modeling pipe has been introduced. Researches on influence of oxygen presence on carried process have been realized. The mechanism of cocking deposition on the walls of channel has been offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Koroteev A. A. Calculations of energy losses and electron beam geometry at its leading to the dense media through the system of differential exhaustion . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 96-104. The work represents generalization of methods for Calculations of energy losses and electron beam geometry at its leading to the dense media through the system of differential exhaustion. Methods of approximate calculations of scattering at multiple collisions with atoms are considered. Parameters of magnetic systems for beam focusing are considered justified, optimal length for transport channels is determined. Method of «enlarged interactions» for numerical computation of cross section of the beam is analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lobanov I. E., Nizovitin A. A., Fleytlikh B. В. Mathematical modeling of limit insulated hydraulic resistance in turbulent flow through turbulence in rough pipes of small diameter . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 105-110. A theoretical model is devised for calculating the limiting isothermal flow resistance in the intensification of heat transfer in tubes due to turbulence in the turbulent flow in rough pipes of small diameter. The model is valid for a wide range of Reynolds numbers, since the correlation with existing experimental data, which allows to predict the reserves of intensification of heat transfer with higher accuracy than existing methods. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A., Manuylov A. A., Fedorov S. ., Yun A. A. Underlying principles of choice turbulent models, using by solve velocity field and temperature condition cooling system wall flame tube combustor gas turbine engine . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 111-115. In present paper maded analisys turbulent models and results simulations heat mass transfer processes near cooling surface oj wall flame tube combustor gas turbine engine. Simulation maded in commercical parcel ANSYS CFX 10.0. Used and analised the next turbulent models: k-e, k-m, SST, 00 -RSM. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shcherbakov M. A., Yun A. A., Marchukov E. Y., Krylov B. A. The use of modern CFD software packages for nozzle jet engine computation. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 116-120. In present paper, the comparison of turbulent models for 2D-channel (backward step channel and fence-on-wall case) has been done. The comparison of numerical results were provided with ANSYS CFX and FastestSD. The following turbulent models have been used: k-Z, k-(u, SST, 00 -RSM, EARSM and Low-Re EARSM. As example of industrial application the thermodynamical processes in nozzle of jet engine were modeled. The practical recommendation for decreasing heat flux to nozzle wall is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
. ., Sidorenko E. K. Analysis of energy balance in the discharge of SPT using results of Its integral parameters and plume characteristics measurements . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 121-129. Results of the power flows analysis in the stationary plasma thruster (SPT) discharge are represented in the paper. Such analysis is interesting for experts dealing with researches of the SPT physics. Particularly it is interesting to understand peculiarities of the power flows change with change of thruster operation mode. It is difficult to realize direct measurement of power flows in the discharge chamber. Therefore the indirect methods of their estimation are subject of author’s interest. And some possible approaches to solve this task are presented in the paper. They are based on the complex analysis of the integral thruster parameters, local plasma parameters in the thruster accelerating channel and plume characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Filimonov A. V., . . Influence of size factor to selection optimal technological parameters of the casting forming process for aircraft machinebuilding" . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 130-133. The method to determine the direction and degree of necessary varyfying of the technological parameters of the casting forming process at varyfying of achieved casting size is developed. Dependes for the calculation of correcting technological parameters oj casting at varyfying of the diameter of ingot (thinkness of casting) for alloys with various tend to formation of cact defects are achieved. Base groups of cast aircraft alloys are considered | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chernomorskii A. I., Feshchenko S. V., Sachkov G. P. Horizontal attitude measurement channel of the nonholonomic uniaxial wheeled platform . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 134-143. The horizon sensor on basis of the accelerometer, which is unperturbed by inertia, is developed in this paper. This sensor provides precise measurement of the uniaxial wheeled platform“s attitude relative to the horizontal plane. The compensating circuit sensors for the accelerometer method error are selected. Relevant simulation results of the wheeled uniaxial platform, taking account oj dynamics of the horizontal measurement channel, are shown | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoilenko M. V. High-precision direction determination and overresolution of radiation sources with the help of wide-angle directional diagram . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 144-153. A new method of high-precision direction determination and overresolution of radiation sources have been suggested. It bases on tomography approach and makes it possible to determine directions to radiation sources with high precision and to reach the sources overresolution by the measurements of integral power at the output of recieving antenna with wide-angle directional diagram. The results of computer experiments are also adduced. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
. . Designing of system architecture for secure real-time telecommunication of mobile objects . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 154-157. Results of the analysis of organizational principals for real-time telecommunications of mobile objects with logical channels including satellite links. standard transport protocols in real time communications. A way to implement secure logical channels for real time telecommunications mobile objects based on modern informational telecommunication technologies. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Repin A. I., Merkishin G. V., Popova L. V. The calculation of the useful signal threshold detection in the laser systems of the initial orientation. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 158-162. In this article it is shown the expression defining the algorithm for the optical treatment of received signals and it can be obtained by means of the methods of statistical receiving and transmitting information theory and then it is made the selection of the structural scheme of optimal discrete signal reception of the optical range modulated by frequency or intensity in appropriate calculate technique of the verisimilitude relationship. There are the computations results and the probability detection using the analytical expressions of performance characterizing the detect process and receiving of the useful signals as well as the computations results in the threshold level. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
. ., Trofimov A. S. Efficiently algorithm of fractal coding . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 163-171. The method of fast fractal compression is proposed in this article. It is (in comparison with well known) allow efficiently decrease time of compression procedure | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zarochinskiy O. I., Eltsov A. К. Shaping the diagrams to directivities in digital receiving antenna arrays by method Monte Carlo . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 172-177. They are stated results of the studies of the using the numerical methods Monte Carlo as algorithm of the functioning the digital system of the shaping the diagrams to directivities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Repin A. I., Yashin M. . he temporary automatic selector with the fuzzy discriminator in the tracking ring. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 178-183. The materials about investigation of the control system, for example the temporary automatic selector with the fuzzy temporal discriminator in the tracking ring, which is a part of system of accompaniment of purpose on distance, are presented in this article. Decisions concerning the mathematical description of fuzzy sets are offered, the general principle of synthesis of fuzzy control systems is described. The brief comparative characteristic of various types of discriminators (digital, fuzzy) is given. By modeling the transients proceeding in the fuzzy temporal automatic selector are received. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Povalyaev A. ., . ., Podkorytov A. N. Integer ambiguity estimation for GNSS-based attitude determination under known measuring devise base vector lengths . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 184-190. The algorithm of pseudophase measurements ambiguity resolution for GNSS-based attitude determination is considered. For attitude determination several antennas located on the object surface are used. In the process of ambiguity resolution additional information in the form of known distance between phase centers of antennas (base vector length) is utilized. The much more efficiency of developed algorithm in comparison with other algorithms is shown. There are results for comparative correct ambiguity resolution probabilities and computer time costs. The possibility of using the single-band and single epoch measurements for attitude determination is displayed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilevsky V. V., Risenberg D. . Algorithm for 3D scene reconstruction in processing of aerospace images. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 191-199. An algorithm for reconstructing a 3D scene given a set of its 2D images from an aircraft is presented. The feature of this algorithm is the proposed method of finding errors in image fragments binding procedure. A camera model is built and equations for finding 3D-coordinates of points appearing on images are deduced from it. A list of parameters required for the algorithm to work correctly is described. The algorithm proposed in this article has been implemented by the authors as a program in C++ language. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kavalerov B. V., Polulyakh A. I., Shigapov A. A., Lisovin I. G. Software modeling complex for testing and adjustment of governors for gas-turbine units of the terrestrial power stations . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 200-211. The technique of software modeling complex development for testing and adjustment of algorithmic provision of automatic control systems for gas-turbine units, used in terrestrial power stations is considered. On the basis of the developed principles of simulation the requirements to the complex of programs, allowing to carry out joint simulation gas-turbine units, synchronous generators and electrical supply system are worked out. Developed software complex gives possibility to test and adjust the control algorithm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V. Boundary layer and its influence on strength of cylindrical shell with a variable thickness . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 212-218. From a position of a three-dimensional problem of the theory of elasticity results of construction of a variant of the specified theory of calculation of cylindrical covers with asymmetrical essentially variable thickness are considered. The essence of this theory consists in construction of the basic intense condition which is based on a hypothesis of a vertical element, and an additional intense condition of the regional flat deformation arising of close rigidly jammed edge. It gives the chance to estimate the stress-strain state of thin-walled aircraft structures both in internal areas, and in narrow boundary zones near to irregularities of type of aviation connections, joints elements of structure with variation in wall thickness, etc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tskhondiya G. A. Modeling the process of a high-density electric-pulse-induced stress relaxation. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 219-224. Multiple experimental tests suggest that a high-density eclectic pulse intensifies stress relaxation in a specific way. In this paper, the process of stress relaxation due to a current-induced dramatic temperature rise was computed via FEM engine using Newton-Raphson method. Computation revealed correlation between the numerical analysis and main experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korovaycev A. V., Korovayceva E. A., Fedotenkov G. V. Locally analytical method of deformed elements state analysis. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 225-229. A modified locally-analytical method for resolving boundary problems is proposed for linear models of deformable elements oj aerospace systems expressed in terms of vectors and matrices. This method makes use of main postulations of grid functions theory, conjugated differential equations, cyclic matrix. This allows obtaining analytic form of integral matrices which is not dependent on inversion of fundamental matrices. The method can be used as a substitute for the usage of grid functions. One of examples of an illustration of possibilities of the method is resulted, allowing to judge its efficiency with reference | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Barabanov K. S., Teplov Y. A., Turischeva M. A. Information risks assessment at enterprise information resources data privacy maintenance in the aircraft industry . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 230-235. This paper represents the model of enterprise information resources privacy assessment in the aircraft industry. We start from the general procedure of enterprise infrastructure privacy protection, based on indicative-algorithmic approach. Further we discuss information security risk model and methods in the phase of preproject enterprise information resources privacy domain research. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vuchkovich A. ., Gavrilova I. S., TsaI I. V. Economic mechanism of development of the productive capacity of the aircraft manufacturers and companies in today's financial environment . Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 236-244. The article demonstrates the role of production and personnel potential of aircraft building plants in providing competitiveness of created aircraft. The article suggests guidelines of interconnected development of production and personnel potential of aircraft building plants when creating all types of aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
. ., Stankevich A. M. Formulation and Solution of the tail assignment problem. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 245-250. This paper is dedicated to the tail assignment problem, which appears on the last stage of the aircraft scheduling process. It is shown how to formulate the problem in terms of the well-known single commodity network model that allows solving it with highly efficient network optimization algorithms. A technique to handle additional constraints for individual aircrafts is proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komissarenko A. I. Calculation of the missile flight velocity in the coast phase of flight. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 251-254. The article deals with the issues related to calculation of the missile flight velocity in the coast phase of flight taking into account the weight and drag changing according to the square law. An analytic expression of the missile flight velocity in the function of the velocity vector angle is obtained. The analytic dependence given in the article is of practical interest for identification of missile flight trajectory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kondratiev A. ., Tiumentsev Y. V. Neural network modeling of controlled motion for aircraft. Aerospace MAI Journal, 2010, vol. 17, no 5, pp. 5-11. Algorithms used for adaptive fault-tolerant control require often to have available some model for a plant. An approach based on the neural network modeling of dynamical systems is a promising technique to generate the plant model especially in a nonlinear case. One of possible ways is suggested to implement the technique. Computer experiment results are presented to demonstrate efficiency of the proposed approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Artamonov B. L., Mojzyh E. I., Ivchin V. A. Modelling of kinematics performance of articulated blade of helicopter main rotor. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 5-16. It is designed mathematical model of main rotor head, working together with the wobble plate. It is obtain dependences of factors of the law of the blade angle control from its azimuthal position, beta angle offlapping hinge and swinging angle of drag hinge. In system ofparametrical solid-state modelling SolidWorks kinematic models of cartridges of various circuits are generated and executed their kinematic analysis which results are compared to the data of calculations. Determine dependences offactors of the flapping compensator and swinging compensator from principle scheme and geometrical parameters of the wobble plate component. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pravidlo M. N. Complex analysis of launch and separation system of aviation guided missiles. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 17-25. In this article are substantiated complex approach to design system for launch and separation aviation guided missiles from aircraft-carrier by aviation launcher and aviation ejection launcher. Results are provided for analysis of aircraft-carrier, launcher and missile influence on ensuring safety of missiles separation. Ways are showed for solving problem of ensuring safety of aviation guided missile separation from aircraft-carrier. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilevsky D. V., Preobrazhensky B. A., Spirin G. G. Thermophysical aspects of pilot interaction with external environment. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 26-29. Method of short-term measuring in the stage of irregular thermal condition can be used for investigation of the thermophysical characteristics of the medicobiological object. Disclosed herein is thermophysical aspect offormation of temperature sensation. Studied hereinafter is termophysical aspects of temperature sensation forming, including burn prognosis. Carried out experimental research of thermophysical characteristics of the medicobiological object's skin, responsible for interaction with external environment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V. Method of calculation of the stress-strain state of elastic rod systems with unilateral communications and a friction in sliding pairs . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 30-39. The universal method of calculation of the stress-strain state is intense-deformed condition of elastic rod system is considered at presence non-linearity, caused by unilateral communications and a friction in sliding steams. Similar communications meet in structures of settings of equipment offlying vehicles, for example, in beam holders, aviation starting and ejection devices with suspended articles, etc. Distinctive feature of an offered method possibility of automation of calculation is. The principle of summation of increments of deformations and the internal efforts arising in the course ofproportional loading of system by external loads is put in a method basis, depending on one parameter that allows to replace the corresponding nonlinear equations with recurrent sequence of the linear equations. As a result it is obviously possible to define level of external loading at which there is a change of settlement schemes. Cyclic repetition ofprocedure of definition of this level makes the maintenance of an offered step-by-step method. It is established, that the account of unilateral character of communications and forces of a friction in sliding pairs leads to essential change of a picture of the stress-strain state of elastic systems | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Cherpakov B. A., Strizhevskiy M. N. Multiple channel system for measuring the temperature during heat strength tests. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 40-43. We consider the problems of the surface temperature measurements during the heat strength test of aircraft armament products.The article describes the multi-channel automated system, which was designed and implemented for temperature measuring | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gromov V. F., Makarov A. F., Korzun A. V. General calculation model of split bar for lateral bending analysis of the wing panel stringers . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 44-47. The article contains the calculation model analysis of panel deformation estimation (in its surface) from stringer joint riveting. Possibility to use a theory of split bar on the elastic foundation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Cherepanov V. V. Identification of models, definition and the forecast of properties for highly porous heat-shielding materials . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 48-57. The complex procedure, allowing to define and predict a considerable part of physical properties of highly porous heat-shielding material, is offered. Its basis is formed by a combination of experiment, statistical methods of mathematical modelling, methods of solving a radiation transfer problem and methods of identification of mathematical models by the solution of corresponding inverse problems. Besides decrease in the expenses, the similar approach essentially expands possibilities of experimental methods. It allows to study and to predict a heat conductivity components, factor of accommodation of energy, complex refractive index and dielectric permeability, scattering indicatrix etc. As the element of the offered approach an original method of the numerical decision of the radiation transfer problem in a heterogeneous flat layer is described. The received results can be applied to creation of the new materials, not destroying quality monitoring and diagnostics, designing of systems of a heat-shielding etc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sirotin A. N. On extremals supposing analytical exposition in the problem of optimum control of the asymmetrical space vehicle rotation . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 58-63. The problem of asymmetrical space vehicle rotation optimum control is considered. As criterion the integral — quadratic functional describing power inputs is chosen. It is shown, that under certain conditions in such problem it is possible to specify a class of extremals, supposing analytical exposition on the basis of existential strains of a solution of equations of free rotation of an asymmetric top. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorontsov V. A. The study of the project problem situations in the development of the automatic spase descent systems . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 64-70. Development of landing unmanned spacecraft to study planets of the solar system is connected with a host of problematic issues. The most significant of these are identified at the stage before the schematic design and formation scheme of the experiment. The choice of means of braking or drift in the atmosphere, means putting them into action and technical solutions depends on the complexity of the problems, opportunities to overcome them and the volume of experimental testing. Methodical approach, in which the analysis of problematic issues is carried out both on the reentry vehicle systems, and on phases of the movement. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Georgiev A. F. Eigenfrequencies habit of aeroelastic aircraft inside domain of dynamic stability. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 71-80. An oscillation of controlled rocket inside airflow in this article is considered. From a control system side there are some requirements to eigenfrequencies and mode shapes of aeroelastic model of rocket. To satisfy requirements the frequencies values can be changed by variations of mass and stiffness properties of rocket. To change the eigenfrequencies of rocket model a classical approach is used: an increasing of stiffness brings to increasing of eigenfrequencies and increasing of mass brings to decreasing of eigenfrequencies. In this article is showed that if oscillation of rocket inside airflow is considered then classical approach is failure. This effect appears inside domain of aeroelastic stability at normal flight conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolesnikov A. V., Paleshkin A. V. Numerical method of modelling of external heat exchange of the space vehicle with any form of external surfaces . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 81-89. The method of calculation of external heat exchange of the space vehicle developed by authors, based on approximation of external surfaces of a space vehicle and visible of a space vehicle a site of a surface of a planet many-sided surfaces with elementary triangular sides and on the subsequent numerical preliminary treatment ofpossible effect of mutual shielding these sides from proceeding from the Sun and a radiation planet is stated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolomentsev A. I., Yakutin A. V. Research of working processes in MEMS based liquid microthruster. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 90-95. The paper represents description of liquid microthruster with thrust of ~ mN. Features of working processes and governing equation are consider. Results of numerical calculation of microchannel without/with chemical reactions and calculation of micronozzle are presented. This results compare with experimental data are published. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lapushkin V. N., Minin N. V. Peculiarity of thermodynamic calculation of low-sized air breathing engine with free-piston drive and diaphragm-type compressor . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 96-105. In the report is considered the problem of creation and study of design of the new type of small-sized jet engine with free-piston membrane supercharger of a fuel mix in which the part is used for internal cooling heat-stressed mobile units of the engine and reception of work of compression of the compressor membrane type. The scheme of the new energy installation is developed. Thermal and thermodynamic calculations by technique of the authors are made. The basic constructive sizes of the engine are calculated and the problem of cooling of piston unit by the charge of a fuel mix of the engine that has led to partial regeneration of heat in a cycle to decrease in the specific charge of fuel and increase in altitude is solved. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sevruk S. D., Farmakovskaya A. A. The possibility and prospects for the use of aluminum as a fuel for oxygen/hydrogen fuel cells in the systems for storage and generate of hydrogen . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 106-116. The results of the experimental studies for «aluminum/water» chemical system are described below. The method of the aluminum activation by contact with water was examined. The kinetic of the ASD-4 and ASD-6 alloys' reaction with water at the different temperatures and in presence of the various additives was investigated. It was found that the most technological characteristics determining the rate of hydrogen production and the degree of aluminum conversation was the temperature in reaction zone, the activator's concentration, the dispersion and the composition of the aluminum alloy used. The experimental data were approximated by the equations that allow to calculate the degree of aluminum conversation at the various concentrations of lithium alumohydride for any time at a certain temperature. The kinetic characteristics of the examined reactions were also determined using the experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikulin A. G. Determination of soot particles concentration in a liquid-propellant engine producer gas using the method of optical diagnostic . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 117-124. The article deals with the method and instrumentation for concentration measurement in the combustion-products condensed phase of the methane-oxygen gas generator. The measurement results of the soot particles concentration in different gas generator operating modes are presented. The measured soot concentration amounted from (2...14)-10-4 % that 2... 3 order less than equilibrium values. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M. About hydrodynamic unsteady turbulent flow calculation. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 125-130. The analyses of hydrodynamic unsteady turbulent flow physical model, created on a basis of experimental research carried out. A model for heat transfer and hydraulic resistance for unsteady flow presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsov D. A., Lebedev A. D. The comparative analysis of structures of stabilizers of an alternating voltage for aviation and space-rocket systems . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 131-136. In article the analysis of block diagram's of the most known types of stabilizers of an alternating voltage for systems of an electrical supply of aviation and space-rocket systems is carried out. On the basis of the spent analysis features, merits and demerits of each block diagram are revealed, the problems connected with designing of devices are considered and possible decisions are presented | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gankin V. I., Gorshkov O. A., Grishanov O. V., Lovtsov A. S., Shutov V. N. Development of KM-88 Hall Effect Thruster with High Specific Impulse. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 137-143. The Hall-effect thruster KM-88 with nominal power equal to 1600 W and specific impulse more than 2000 s has been developed in Keldysh Research Center. The results of development tests are presented in this paper. The capability of the thruster to endure external impacts (vibration, shocks, transportation loads, changing of negative and positive temperatures, climatic factors) has been shown. The lifetime test has been successfully done with 1000 hour duration. The comparison of obtained results with tests of other thrusters is presented. The levels of loads during tests correspond with requirements called for flight experiments as part of spacecraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ignatyev F. N. Prospects and problems of using the quantum-size semiconductor heterostructures in optoelectronics . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 144-150. Possibilities to use the quantum-size heterostructures for conversion of optical signals are investigated. In maintenance of the offered mechanism of conversion the nano-size semiconductor heterostructures were developed. Analytical expressions for rate and quality of conversion are received. Preliminary estimations show that quantum-size structures can be used for working out of optical converters, modulators, multiplexers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Frolova O. A. Uav fault-tolerant complex altitude measuring system. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 151-158. The paper treats the problem of an UAV low-altitude flight over a wavy water surface. Procedures for in-flight wave height estimation using radio altimeter measurements are given, the possibility for seas estimation algorithm implementation is analyzed. The obtained results are verified using the mathematical simulation | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Repin A. I., Merkishin G. V., Losev V. Y. The transitional processes in fuzzy control systems of aircraft side movement. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 159-163. Determinate and stochastic systems of automatic control are used for ensuring the safety of aircrafts flight. At good mete-vision (the 2-nd category ICAD and more) their usage is justified. For flying in more sophisticated conditions the known methods and tools do not juild the proper effect [1]. Then it is appropriate to employ the theory fuzzy control for designing such systems [2,3]. The article presents the structural scheme of the known control systems and systems based on the logical-linguistic approach. Their comparative characteristics are given. Then transition processes in the fuzzy system of automatic control for aircraft side movement are computer modeled. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Repin A. I., Vokhminov E. N. Application strategy of accelerations measurement information system on the basis of acousto-optics method . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 164-167. In this article some improvements to tactical-technical characteristics of orientation and navigation systems are described. Acoustic methods or methods based on photoelasticity effect can be used as sensitive elements of measuring of rocket own movement parameters. Optical, radio engineering, and other devices and systems can be applied for capturing information. In the present work special attention is given to comprehensive investigation of Mossbauer's effect. Its application will ensure functioning of real-time systems with sufficient accuracy which in many cases defines the alertness timing and the level of tactical technical rocket mission performance with any given orientation and navigation system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Merkishin G. V. Presenting of location image as summer for binary relation among shining points. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 168-171. It is regards the presenting of location coherent signals as the summer for space harmonics from radiating of shining points. Image of located object is formed as summer for binary relations among shining points pairs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pychkov A. M. Additional definition of the astatic control principle for sistems with coordinate-combine flight apparatus control . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 172-183. In conditions of coordinate-combine flight-apparatus control the role channel is very important. The problem consists in high-dynamic realization of sign-alternative control signals. In this paper two solution variants of this problem are considered and described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vikulov A. G., Vikulov D. G., Mesnyankin S. Y. The method of the generalized resistances for complex investigation of the thermal conductance . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 184-191. The electro-thermal analogy and the interaction aspects are investigated. Their criteria are defined. The electrical and the thermal conductance invariants are drawn out as generalized resistances. The interaction of the electrical conductance and the thermal electronic one is studied. The capability of the application of the analogy and the interaction laws to the contact conductance is considered. The calculation expressions for the generalized constriction resistances actual in space power plants are proposed. Their limits are analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gromov V. F., Makarov A. F., Korzun A. V., . . Differential equation of stringer lateral bending as a split bar on continuous non-central joint . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 192-196. The article contains analytical analysis of bending differential equation derivation of a stringer with off-center positioning of the riveting joint. Model of a split bar on discrete elastic foundation is used within. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuprin I. L., Davydov A. D., Vinogradov S. M. Problems of economic-mathematical modeling development prospects of the modular missile complexes . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 197-201. In article results of some works of authors on introduction support in fundamental and applied research works of substantive provisions of modular strategy of development of the missile complexes are reflected. On the basis of the analysis of economic-mathematical features of the modular missile complexes risks of inadequate realization of modular strategy of development and its temporary outcome through the mixed strategy are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brodsky A. A., Brodsky A. V. Automated message exchange tariff calculation in specialized civil aviation network . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 202-206. This paper is dedicated to issues of building methodological base for informational services provided within specialized network of civil aviation by telegraph messages. Specific is considered of the technological process of information exchange and problems defined to be solved for performing calculations. A technique is proposed for automated tariff calculation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bazadze N. G. The concept of organizational designing as the tool of creation of the organizational mechanism of innovative economy . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 207-213. In article the concept of times of the decision of a problem of investment development of domestic hi-tech sector of economy without attraction of investments on the basis of development of workings out of domestic school of the scientific organization of work and adaptation of foreign experience of the developed economy on economical manufacture is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubovik M. V., Nizhegorodtsev R. M. The problems of management for counteragentic competitiveness of industrial enterprises and their aggregations . Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 214-218. The category of counteragentic competitiveness is substantiated. The paper discusses main factors impact counteragentic competitiveness of industrial enterprises and their aggregations from the institutional viewpoint | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Strategy Development for Corporations and Enterprises. Aerospace MAI Journal, 2010, vol. 17, no 4, pp. 219-230. The paper presents a systems description of corporations' and enterprises' strategy development process based on a competition analysis as well as internal and external factors affecting the enterprise. It is important to note that the paper not only presents the systems description of strategy development process but also gives, based on experience, examples of corporation strategy development. This makes it possible for students, graduate students, masters, professors, employees of aviation industry enterprises to have a theoretic and practical systems material for the practical development of corporation strategy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parafes S. G. Method of structural-parametric optimization of constructive-technological patterns of low-aspect lifting surfaces . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 5-17. In paper a method of structural-parametric optimization of constructive-technological patterns of low-aspect lifting surfaces is proposed. The design structure is understood as the constructive-technological pattern. The choice of the best possible constructive-technological pattern is made as a result of the decision of an identification problem of alternative constructive-technological patterns with a preliminary found optimal design. The optimal design is a minimum of weight distribution of a material, satisfying with the requirement of strength and aeroelasticy. An example of structural-parametric optimization of constructive-technological patterns oj low-aspect lifting surfaces is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ermakov S. A., Karev V. I., Mitrichenko A. N., Selivanov A. M., Sukhorukov R. V. Control actuation systems of civil aircraft. New developments and reliability. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 18-29. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuznetsova E. L. Heat and mass transfer in thermoresisting compoisite materials under high-temperature loading . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 30-36. Based on both nonlinear filtration ofpyrolysis gases in porous residues of destructing composite materials and binding agents destruction models a new complex mathematical model of heat-resistant composite protections for flying vehicles subjected to high-temperature loadings by hypersonic gas flows is presented. A numerical method to solve the formulated problem is also described. The proposed nonlinear filtration's model is useful to compute the below boundary ofpyrolyse gases flow stagnation's pressure needed for linear model's applicability domain defining. The numerical results' analysis proofs that the proposed modeling approach is able to describe composite materials' heat state theoretically. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Selivanov A. M. Electricity supplied electrohydraulic drive with combined control of output speed. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 37-41. The new scheme of electricity supplied electrohydraulic drive for flight control system is advanced. It is notable for using throttle or volumetric control of speed subject to control signal value. His scheme, operation as well as merits and demerits are considered in comparison with Electrical Hydraulic Actuator. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pravidlo M. N., Daneko A. I. On methods of parameters determination of aviation missiles separation, during ground testing of aviation ejection launchers . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 42-45. In this article are discussed methods of conducting test bench (ground) testing of aviation ejection launchers and experimental data evaluation, allowing getting required parameters with greater precision for required parameters and characteristics for correcting mathematical models of these units. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kim N. V., Kuznetsov A. G., Krylov I. G. Application of systems of technical vision on pilotless flying machines in problems of orientation to districts . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 42-49. The problem of an estimation of orientation of a small-sized unmanned vehicle concerning land reference points with by a technical vision systems is considered. Algorithms of search of reference points are considered. The analysis of accuracy of an estimation of co-ordinates concerning reference points is carried out. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Petukhov V. G. Robust suboptimal feedback control for low-thrust transfer between noncoplanar elliptical and circular orbits . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 50-58. It is considered the synthesis of robust suboptimal feedback control based on minimum-time multi-revolution transfer between non-coplanar elliptical and circular orbits in the inverse square gravity field. The problem is solved using asymptotic nature and symmetries of optimal control on the unperturbed trajectory. It is shown stability of the feedback control with respect to perturbations and deviation of initial conditions. Derived suboptimal feedback control can be used for providing of spacecraft autonomy and for mission design purpose. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voronich I. V., Myint Z. M. Feature influence of gas-surface interaction on the aerodynamic characteristics of aerospace vehicle . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 59-67. The paper presents results of calculation of aerodynamic characteristics of typical aerospace vehicle, obtained with the Monte-Carlo method based on two different gas-surface interaction models — Maxwell model and Cercignani—Lampis—Lord (CLL) model. With the use of these models sensitivity of force and moment coefficients of vehicle in hypersonic free molecular flow to variation oj accommodation and temperature properties of surface has been studied with multiple molecular reflections taken into account. Corrections to aerodynamic characteristics, given by CLL model, are defined. The technique and results can be used for aerospace vehicle design. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Konstantinov M. S. The analysis of use of Moon's swingby for providing a vector of hyperbolic excess of velocity at flying away from the Earth . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 68-77. The opportunity of use of Moon swingby is researched at realization of a trajectory of interplanetary flight. It is researched the flight plan at which due to a velocity impulse at low Earth circular orbit a spacecraft (SC) gets in a vicinity of the Moon, before to ins ert in to a heliocentric trajectory of flight. Due to Moon's swingby a spacecraft gets additional velocity, which allows reaching a planet of destination with smaller expenses of characteristic velocity of a chemical upper stage. In work the detailed analysis of the scheme of flight and the strict proof of possible existence of several types of trajectories of a space vehicle with lunar gravitational maneuver is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Grebennikov A. I. Fast solution of inverse heat transfer problems by general ray method and applications to modeling of nanostructured materials . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 78-81. We consider mathematical statement of the inverse heat conduction problem as inverse coefficient problem for linear parabolic equation. New General Ray (GR) method for solution of this problem is proposed. The method is based on reduction of Partial Differential Equation (PDE) to assemblage of Ordinary Differential Equations using local traces for considered functions and operators. GR-method presents the solution of the inverse problem for this type of equations by explicit analytical formulas that use the direct and inverse Radon transforms. Proposed version of GR-method can be realized as algorithms and computer software faster as all known ones, based on traditional approaches. This is very important for mathematical simulation at the developing ofnanostructured materials with special heat-conductive properties. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rodchenko V. V., Sadretdinova E. R., Gusev E. V. Choice of parametres of penetrator for research of a lunar ground. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 83-90. The project «Moon-Glob» urged to investigate internal structure of the Moon. For realisation of this project it is necessary to solve a problem of introduction ofpenetrators in a lunar ground on depth of several metres. In article questions of a choice ofparametres of penetrators for movement in the lunar ground, using as a power-plant the rocket engine of firm fuel are stated. Questions oj improvement of taktiko-technical characteristics by use of devices of various constructive decisions are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Beschastnykh V. N., Ravikovich Y. A. Gas bearing for heavy gas turbine rotor. Experience in the design and implementation . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 91-98. There is an area of applications of turbomachines where use of gas-lubricated bearings is economically expedient at rather heavy rotors. It is a question of turbogenerators capacity of 500—2000 kw with high-frequency electrogenerators. In article results of designing and experimental researches of gas bearings of a turbogenerator by capacity of 1000 kw are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Anikeev A. A., Bykov L. V., Molchanov A. M. Simulation of supersonic nozzle cooling. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 99-107. In this paper the results of simulation of conjugate heat transfer between high-temperature flow and model nozzle are presented. Different types of heat shielding (convective, porous and film) were considered. The presented methods were developed for liquid-fuel rocket engines but it is rather an illustration ofAnsys CFX package solver capabilities in this area, than a simulation of some specific engine with its own type of fuel, principal scheme, etc. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bykov L. V., Molchanov A. M., Yanyshev D. S. Numerical method for supersonic turbulent reacting flow simulations. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 108-119. The numerical method for high-speed turbulent gas flows with non-equilibrium chemical reactions has been developed. The full Navier-Stokes system (with Reynolds-Favre averaging) is being used. The system is solved using the fully-coupled implicit numerical approach. The modified Steger- Warming split method is used for connective flux, treatment. Sources in the reaction equations are presented in the implicit form. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ovchinnikov I. V., Homjakov A. M. Bearing capacity of reaction turbine impeller. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 120-128. The work considers elaboration for methods to determine the bearing capacity for reaction turbine impellers for all range oj loads fr om centrifugal forces, differential pressure and thermal load. Analytical methods for construction of limit surface based on bearing capacity theory and for calculating margin of safety using the constructed surface wh ere elaborated. Finite element analysis with nonlinear material model and temperature dependent material properties, implemented in MSC.Nastran software, was used for more precise construction of limit surface. Special software was developed for automation of limit surface construction. Analysis of the surface allows for more precise turbine's margin of safety calculations and helps to decide for better ways to uprate turbine. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kotel'nikov V. A., Kim V. P., Kotelnikov M. V., Sidorenko E. K. Probe measurements in a stream of the rarefied plasma. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 129-134. Physical, mathematical and computing models of a probes problems for streams of the rarefied plasma are considered. Results of calculations for probes of cylindrical geometry are presented. Processing techniques of a probes experiment in a case when all charged particles are in one plasma formation, moving with the same directed speed, and also in a case when the rarefied stream of plasma moves through the rarefied background plasma are offered. Results of processing of probes experiment which was spent in a stream of the rarefied plasma expiring from the stationary plasma engine (SPE) are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobiev A. G., Borovik I. N., Kazennov I. S., Lahin A. V., Bogachev E. A., Timofeev A. N. Development liquid rocket engine of small thrust with combustion chamber from carbon-ceramic composite material . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 135-142. The technical paper about problem of development liquid rocket engine of small thrust with ceramic-composite combustion chamber. The review is presented of actual state of problem. The analysis of energy efficiency is presented for rocket engine of small thrust with ceramic-composite combustion chamber developing in MAI. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilyev V. Y. Rational enhancement of convective heat transfer by dissection of long smooth ducts. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 143-152. Regular experimental research is executed for enhancement of convective heat exchange in rectangular dissected ducts in aerodynamic tube of interrupted type. It is shown that the process for rational enhancement of convective heat exchange (RECH) is realized and it is determined by the condition [(Nu/NurjI)/( С / С гл)1 rc = idem - 1 anc^ 's reliably governed by the change of values of basic dimentionless parameters. Graphic dependences are offered allowing to define and observe continuous change of values and key parameters of RENT process in all area of its realization on number Re which is interested the designers of heat transfer apparatus (HTA). The received results can be used at designing of enhanced HTAfor various purposes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilyev V. Y. Effectiveness of process for rational enhancement of convective heat transfer in ducts with discrete turbulizers . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 153-162. Way of artificial turbulization in wall layer of currents on diffuser-confusor sites is realized in rectangular tubular-plate ducts with cross ridges and grooves (TPrg) of heat transfer surf aces (HTS). The results of experimental researches on heat aerodynamic characteristics of TPrg HTS have confermed the realization of process for rational enhancement ofconvective heat transfer (REHT) and high level of estimations at value (Nu/Nu )' of a determining complex [(Nu/Nura)/( С / С гл)] Re=idem = 1 • F°r the first time it was offered and realized the technique of definition and tracing of continuous change of values of an estimation (Nu/Nu )' for investigated groups TPrg HTS, the basic geometrical dimentionless and regime parameters is realized within the limits of all area for realization of REHT process, simplifying the search of rational decisions and designing of heat transfers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidov A. S., Kashelkin V. V. The experimental and calculation estimation of structure elements damage. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 163-167. The structure elements multistaged model of damage is suggested. It is connected with the creep curve and dependence oj logarithmic decrement on time. The numeral evaluation of damage on stainless steel samples with suggested model is made. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shulov V. A., Bytzenko O. A., Teryaev D. A. Deposition of nanocrystal corrosion-erosion resistant coatings on the surface of titanium alloy parts . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 168-177. This paper reviews researches on deposition of TiSiB erosion resistance nanocoating with MAX-phase on the surface of Ti6Al4V alloy parts by vacuum plasma method with plasma separation from drop fraction, on physical and chemical state of surface layers, fatigue and erosion properties of samples and blades with these coatings. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Terentiev M. N. Simulation Model of Power-save Wireless Sensors Network with Timescales Synchronization . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 178-183. A problem of simulation is discussed for nodes of wireless sensor networks. In addition to previously suggested mathematical model for wireless sensor networks with energy saving and synchronization of time scales, author suggests a simulation model for estimation general parameters of network topology. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Okhotnikov D. A. Non-contact radar monitoring of the pilot state during his work on the training simulator . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 184-192. Monitoring physiological parameters of pilot is considered in the article when he works on the aircraft or helicopter training simulator under extreme conditions. Non-contact radar surveillance of heart and breathing rate by means of chest moving measuring is used. The true trajectory obtaining on the base of radar data in seesaw motion of the chest is treated. Mathematic methods oj radar measurement data processing are proposed, filters are constructed, which allow to eliminate signals reflected from local objects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuznetsov Y. V., Baev A. B., Konovaluk M. A. Multi-point scatterer target identification using radar image spectrum. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 193-198. The coherent ultra short pulse radar provides high resolution image of the target. A model of this image is the superposition oj the complex envelopes of the signals retunedfrom the point scatterers. The values of the complex envelopes are distributed over radar image coordinate plane in accordance with their positions and reflection coefficients. Radar image model is based on the known radar pulse envelope and a pattern of the antenna. The parameters of the target point scatterers are processed in the frequency domain by using of one dimensional data extracted from the two dimentional FFTofthe radar image. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Il'in V. N., Grishin R. A. The analysis of en/decryption algorithm implementation variants employing two-leveled macromodeling . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 199-204. An analysis of en/decryption GOST 28147-89 algorithm implementation variants' is carried out in order to determine the best variant at the early design stages. The algorithm field programmable array implementation 's(FPGA) output parameters evaluation is mainly considered. In order to evaluate the output parameters the two-level macromodeling method is used. It's usage enabled the substantial computational complexity reduction in comparison with known methods. It's shown that the results obtained using the two-level macromodeling method are adequate and precise enough. As a result of the carried out analysis the decision was taken to implement the algorithm using FPGA and the best, in the selected matter, device structure was determined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoilenko M. V. The mathematics of tomography approach to multichannel signals processing. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 205-212. Mathematics of the new, tomography, approach to multichannel signals processing is given in the article: the multichannel tomography problem mathematical formulation and its solution methods. It also contains references to the publications of new solution methods of a number of problems in the sphere of radiolocation received with the help of the suggested approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Temnov K. A. Improved tracing of the design documentation of electronic. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 213-221. Modem vectorizers have low efficiency of recognition of the design documentation of electronic. In this paper I propose an algorithm that increases the efficiency of tracing through the proper labeling of text and graphic components of the binary images oj the design documentation. Application of quadtrees for labeling and extracting text and graphics components on binary images with the following clustering of labeled components to text and graphics is described in the article. Proposed algorithm gains an advantage over sequential application of image components labeling algorithms and algorithms of text extracting in the image. Described algorithm allows to select the text components in noisy images with high reliability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pegachkova E. A. Methods of approximate synthesis of optimal linear logic-dynamical systems. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 222-225. We consider the problem of active stabilization of a satellite with a minimal fuel consumption. The solution in the classical frames provides a minimizing sequence with infinitely many switches in the engine during infinitely short time intervals. However, this infinite impulse strategy is practically поп — realizable. Hence we suggest to take into account the number of switches, solving the problem within logic-dynamical systems (IDS). We get an approximate solution basing on the necessary optimality conditions for LDS. We compare these necessary conditions with Pontriagin maximum principle, discuss the results of some calculations and their practical utility. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybackov K. A., Khakimov Z. R. Application of the Spectral Method to Linear control system identification. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 226-229. We suggest the new approach to linear control system identification with using the spectral form of mathematical description. The proposed method allows to transform linear integral equation into the linear algebraic equations, and to arrive at a solution in an explicit form. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yanchishin A. M. Aviation Industry Enterprise Market Risk Premium Evaluation Model. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 230-234. World financial crisis showed the inefficiency of risk evaluation models being used by most of financial and industrial sector enterprises which decreased the value of Weighted Average Cost of Capital and increased the value of the assets. . Methodology being described in this helps to evaluate market risk premiums for aviation industry enterprise more precisely by modifying of Capital Asset Pricing Model methodology. Calculation based on fundamental factors helps to avoid average value mistakes, regression analysis valuating connection between country economy growth and certain type aviation industry enterprise evaluates the risks of certain market segments together with different risk levels of mature and emerging markets. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Klochkov V. V., Rusanova A. L., Maximovsky V. I. Economic-mathematical modeling of new civil aircraft production launching processes . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 235-245. The model of civil aircraft market competition is considered, in which product's market entry time lag is compensated by better quality than leader suggests. The aircraft companies' innovation policy optimization methods are suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kochetkov V. I. Lean technologies in aviation manufacturing. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 246-249. The article decribes the principles of lean production and shows which resources technologies may be applied in aviation industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chaika N. K., Zverev A. M. Prediction financial result of the aviation enterprise in modern terms. Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 250-253. In the article have solved the problem of prediction financial results of the aviation enterprise. The authors have analyzed key features of the aviation enterprise. The authors have suggested stochastic planning method of prediction financial result of the aviation enterprise in modem terms. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ageyeva N. G., Sangadiev C. Z. Organizational problems of modular adoption of a corporate information system in the aviation industry . Aerospace MAI Journal, 2010, vol. 17, no 3, pp. 254-258. The article is considered value of IT in aviation industry. The method of phase modular adoption of corporate information system is offered in the integrated structure (enterprise) of the aviation industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuprikov M. Y., Dolgov O. S., Kuprikov N. M. Features detection of moment-inertia shape future aircraft in the early stages of design. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 5-15. In report is widely descripted a new approach to the analysis of inertia-moments of aircraft design, based on solving the inverse problem and identified the boundaries of the existing methods for determining the inertia-moments of perspective aircraft, a new direction to develop new methods for determining the inertia-moments of the aircraft is suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pacuk W. ., Mukhina M. В. Conceptional method of dynamic systemssequential parametric identification. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 16-18. This article describes a new algorithm for identification of models of complex dynamic systems. The main point of this method is in decomposition of the initial task of identification on the basis of qualitative analyzing sensitivity parameters depending on the changes at different timely intervals of simulation. Unknown parameters necessary to quantitative description of a dynamic system are defined through morphological analyses of starting task and further decomposition to increase its parameters. While using such a procedure we can solve iterational logistics of small-size optimization problems to define the initial task of parametric identification. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balanovskiy L. V., Golovin D. L., Sarylov O. V. Creation of system of electromagnetic safety of technical systems for space complexes of the Russian Federation. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 19-22. In this paper problems of safety and electromagnetic terrorism are considered. Researches of electromagnetic compatibility enable to improve quality and reliability of the aviation equipment, safety systems of aerospace complex objects, atomic industry, customs and frontier service. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Markin L. V., Shatnyy A. В. Sybsystem providing optimization of the commercial load allocation onboard aircraft. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 23-30. The question considered in the article is related to the increase of cost-effectiveness of air transportation at the expense of allocation optimization of commercial cargo onboard an aircraft. It is reached by the creation of the automatized system of the load-planning as the plug-in module for existing aircraft «weight & balance» and centering systems to achieve the maximum approach of center of gravity actual value to the calculated optimum center of gravity. Methodological bases are detailed and the researches and tests results of application of such system in the working process of «Lufthansa» airline are described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grumondz V. T., Korzhov D. N., Makhrov V. P. Stability problem for steady-state motions of high-speed underwater vehicle equipped with an aft wing. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 31-35. A stability problem for steady-state motion is considered as applies to underwater cavitating vehicle equipped with a T-shaped wedge-like aft wing. Similar problem is discussed as well for the vehicle with an annular wing which is involved into generation oj an aft cavity with negative cavitation numbers. Steady-state stability conditions are derived analytically for the first problem and numerically for the second one basing on integration of the vehicle equations of motion. Both cases are considered in regard to the vehicle motion with a constant depth value. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rodchenko V. V., Gusev E. V., Sadretdinova E. R. Mathematical model of reliability of system of gas supply of a technical complex. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 36-43. In article the substantiation of structure and quantitative values of indicators of reliability of system of gas supply of a technical complex is spent. The mathematical model of reliability of system of gas supply of a technical complex taking into account possibility of restoration of an efficient condition after refusal in the course of performance of works is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brodsky A. V., Novikov D. В., Padalko S. N., Strogonova L. В. General scheme of automated medical check in DMSS of Long-term space flight life support. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 44-52. This publication is devoted to Decision Making Support System (DMSS) development to be used by crew doctors during long-term space flights in order to perform permanent medical monitoring of crew members. The technique is proposed for an automated crew members health monitoring: basic principles andformalization, sources and methods to obtain necessary input data, general scheme of DMS system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidova N. S., Shangin I. A. The project image of electrochemical system of water reclamation with locked water-flow circuit of concentrating. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 53-59. This article concerns the questions of complex experimental-theoretic researches of complicated chemical-engineering procedure of electrochemical system of reclamation of working polyphase medium. The work is aimed at creation of methods of design calculations for electrochemical system of water reclamation for space purpose and methods of operation for structure working environment and ways for process and intensification of mass transfer applied to water reclamation systems for complexes supporting the life activity at space station. There were defined the optimal ranges of amper density 0,001 — 0,005 A/cm2, the volume in and out channel, of mixing basin and consumption of working blend in range of Reynolds' s numbers 1—10 also the numbers of electro dialysis cells which provide the required level of working environment purification. The experimental researches have proved the chosen option of operating-technologic characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nenarokomov A. V., Titov D. M., Munoz Gonzalez V. . Computer design of non-destructive thermal protection of spacecraft. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 60-67. Design of distributed parameter systems, shape optimization and other free or moving boundary problems may be thought of as shape inverse problems, in which the positions of free boundaries are determined along with the solutions of field variables. In the case under consideration such conditions are constrains on the temperature values at the discrete points of the system. At presented paper algorithm for optimal design of multi-layer thermal insulation is consider. This algorithm based on a sequential quadratic programming (SQP) method. Results are presented how to apply the algorithm suggested for solving a practical problem — thickness sampling for a spacecraft thermal insulation system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Manbekov D. R. Guarantee of a symmetrical reversal of polarity of full-bridge converters with Current control mode. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 68-72. The author showed the possibility of guaranteeing the symmetrical reversal of polarity of the core of power transformer in the full-bridge converter with Current control mode. At the same time is ensured the functionality of converter both in the nominal and in emergency working conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bodrov A. V., Lapushkin V. N. Theoretical research of possibility of creation small high-rise jet-piston power engine for UAV. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 73-77. Experimentally-theoretical research of possibility ofpressurisation small duple engine, is conducted by the centrifugal compressor resulted by it. The superfluous blowing-off mix cooling gas exhaust path and burnt in the pulsing jet chamber is burnt together with products of combustion of exhaust piston power engine. Thereby, creating a resultant draught the power. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Prokof'ev M. V., Smolnikova O. N., Bibikov S. В., Kuznetsov A. M. Influence of conditions of heat treatment on the structure and properties of the coatings from colloidal-graphite dispersions. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 78-86. X-ray researches of chemically activated graphites used for reception of steady kolloidno-graphite dispersions are executed. They have been determined the X-ray characteristics of the original graphite pastes and conductive coatings obtained by precipitation from aqueous and alcoholic colloidal dispersions of graphite particles on various dielectric substrates. The influence of heat treatment on the structure and electrical conductivity of such coatings has been studied. The presence of amorphous phase component oj graphite material is revealed by the methods of X-ray diffraction analysis and is discovered the considerable reduction of its content in the process of powder activation of graphite, connected with the partial burning out of amorphous component and the structural packing of material. It has been established that the heat treatment of graphite coatings at temperatures of 1000—400 degrees leads to an increase in their specific conductivity as a result of the removal of thermally unstable groups on the area of the particle oj graphite and packing of carbonic film. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sitnikov S. A., Fetisov G. P., Lomazov G. V. Silicon nitride-based ceramic composite materials technology development. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 87-90. Manufacturing technology of composite heat-resistant ceramic for details of aviation engineering and electric power plant. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sekretarev V. E. Mathematical and software for development of the onboard computers and organization of her interaction with extern environment . Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 91-100. In article are considered questions, connected with the development and debug onboard information and computing system. It is realized description mathematical and software for creating automated complex, intended for debugging onboard computers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Nguyen N. M. Designing mathematical imitator of flight control algorithms. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 101-113. Task of estimating effectiveness of employing complex measurement processing algorithms in control system of the aircraft was considered. Solution of this task based on employing complex mathematical simulation was proposed. Three different complex measurement processing algorithms were investigated. Statistic simulation was carried out and descriptions of errors of estimation oj status variables of aircraft were calculated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Busurin V. I., Khodin M. M. Automation system for profile building of cylindrical body surface. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 114-120. In the article the automation system for prof He building of cylindrical body surface is considered; the functional schematics oj the system based on cylindrical body contact scanning method is proposed. The breadboard of the scan profilometer and the control of scan profilometer using communication ports of personal computer are described. Program control methods for step motors and linear displacement sensor are realized; the data base for the storage of cylindrical body test results is developed. Architecture oj program complex for scan profilometer automation is proposed; scan profilometer error analysis is conducted and ways of theirs compensation are proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolesnik S. A., Kuznetsova E. L. Simulation of conjugate heat transfer on boundary of anisotropic bodies using analytical functions. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 121-126. In this paper conjugated heat exchange is studied on example of analytical solutions for second initial-boundary problem oj heat transfer in anisotropic plate coupled with elementary boundary layer problem. A method is developed for solving conjugate problems of boundary layer and anisotropic heat transfer, which results in systems of nonlinear equations for temperature at conjugate boundary points. Mutual influence of heat exchange is studied for variation of principal axes direction and values of principal coefficients. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Egorova O. V., Zhavoronok S. I., Rabinsky L. N. Middle thickness shell's interaction with acoustical wave. Aerospace MAI Journal, 2010, vol. 17, no 2, pp. 127-135. A non-steady dynamics' problem for an elastic shell interacting with waves in liquid media is considered. The coupled hydroelasticity equation's system for both shell and media is reduced to the equation's system of damped motion of shell, where damping is described by the integral operator in the time domain. The operator's kernel is the surface transition function, derived as a fundamental solution of the problem of acoustical wave diffraction on the convex surface. This auxiliary problem is solved approximately using the thin layer hypothesis, considering the damping in the liquid media. Integra-differential equations of shell's motion in damping media are solved numerically using finite-difference schema of differential operator's discretization and trapezoidal schema of numerical integration. The presented results are developing the earlier results published in [5]. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Endogur A. I., Pankevich A. A. Structures weight comparison of commercial aircraft with different aerodynamic schemes. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 5-9. The structure scheme weight analysis of commercial plane are discussed. There is a comparison ofefflsient weight of aircraft structure for planes of different aeridynamic schemes. The analysis of the aerodynamic schemes influence on weight of planes was made. The opportunity of different schemes based on the identical technical project is shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Popov Y. I., Stoljarov D. V. The experimental calculated method of analysis for tail part of fuselage frame of integral composition fighter. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 10-17. Herein experimental methods aimed for effective rational design of integral scheme fighter fuselage tail section parts are considered. Engine pod junction structure is subject to analysis with its forth section in case of spreadengines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gromov V. F., Dunaev V. V., Eryomin M. V., Makarov A. F. Improvement of aviation structure quality and life in mechanical joint. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 18-24. The article is related to parameter analysis of hidden mechanic joints. Structural-technological methods of improving of quality and performance characteristics are reviewed and supported by different kinds of joint sample tests. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Maslov A. D., Zavalov O. A. Working out of the layout schemes of removable modules for the helicopter Ka-226AG in 3D modeling environment. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 25-32. With using CAD system it is developed the layout schemes of removable modules for the helicopter Ka-226AG in the interests of fuel and energy complex enterprises. The structure and placing by the helicopter of the target equipment is defined for each module taking into account a real design of units of the helicopter. Results of work conform a basis for performance of the outline sketch of removable modules. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Popov Y. I., Stoljarov D. V. The influence of arrangement of joist and ring parts of power frame 'to distribution of mass and load. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 33-41. Herein strength and parametric analysis methods aimed for quality definition for fuselage tail section lateral axis based structures are considered relative to integral scheme fighter. Full-scale power rib is subject to analysis with ring located around engine pod section of twin engine airplane with spread engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Tomilin M. M., Gordeev S. V. Research shielding efficiency of on-board cables. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 42-44. Herein experimental methods aimed for effective rational design of integral scheme fighter fuselage tail section parts are considered. Engine pod junction structure is subject to analysis with its forth section in case of spreadengines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Anashkin A. U., Nesterov V. A. Development of criterion of safety cargo ejection from aircraft-carrier. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 45-48. In work selection of criterion of safety cargo ejection from aircraft-carrier inner section is described and method of criterion calculation is represented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev G. V., Kulkov V. M., Yegorov Y. G., Sharifullin R. R. Electromagnetodynamic tether system in low-orbit satellite motion control tasks. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 49-54. Low-orbit satellite with electromagnetodynamic tether system (EDTS) motion control methods are presented. Efficiency EDTS using for low-orbit satellite maneuvering analyze is described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alekseev V. A., Kudriavtseva N. S., Malozemov V. V., Pichulin V. S., Titova A. S., Shangin I. A. Mathematical modeling of heat processes of miniature unboard equipment. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 55-61. Mathematical modeling of heat processes of miniature onboard equipment (МОЕ) for operation in nonpressurized modules is discussed. It is formulated and solved the problem of criteria conditions determination providing the temperature field of МОЕ operating in a spacecraft identical to the temperature field of the same МОЕ operating in climatic chamber under equal heat generation of the instruments. It allows us to change the expensive thermal tests for МОЕ in heat vacuum-chamber by much more cheaper thermal tests in climatic chamber. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kovkov G. V., Malyshev V. V., Fedorov A. V. Advanced astrophysical system segment evolution and stability. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 62-71. Ballistic layout for advanced astrophysical space system is under consideration. Spatially scattered spacecraft orbits dynamics is analyzed. An approach to maximize an arm of a radio interferometer at the expense of a high apogee orbit disturbance is suggested. Numerical simulation results are given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rodchenko V. V., Pichuzhkin P. V., Paleshkin A. V. Decrease in the ecological damage at regular and supernumerary operation is rocket the space technics. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 72-80. In article ways of decrease in probability of an emergency outcome of flight of a product are presented is rocket the space technics and the estimation of dispersion of points of falling of the fulfilled steps is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nenarokomov A. V., Netelev A. V. Identification of the mathematical model of heat transfer in destruction material. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 81-87. In this work present algorithm of identification thermal characteristics destruction heat-shielding materials, based on methodology of inverse problems. At the decision inverse problem the vector of required characteristics consisting from 7 none-linear depending from temperature component (heat capacity, thermal conductivity, heat capacity of filtered gas, heat effect decomposition, and parameter of the Arenius equation is defined: sedate parameter, before exhibitor factor and energy of activation). Stability of the decision inverse problem is reached by application in algorithm of a method iterative regularization. Iterative process for a vector of required parameters is based formula gradient methods of optimization: us=us-1+γsgs, s=1,...,s* Where u — vector of unknown functions, s — number of iteration, γ — descent step, g — increment of unknown functions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golubev I. S., Levochkin S. В. Substantial basis of design competitiveness of flying vehicles. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 88-96. Actual competitiveness of flying vehicles is formed by the market to many formal and informal signs at acts of purchase and sale. These signs (competitive advantages) along with target efficiency, should be provided at designing of flying vehicles. In article the concept of design competitiveness of the flying vehicles is offered, defining which factors are the technical perfection, competitive advantages and a market price. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobiev A. G., Borovik I. N., Hohlov A. N., Lizunevich M. M., Sokol S. A., Gurkin N. К., Kazennov I. S. Modernization of fire test for investigation of working process in liquid rocket engine of small thrust with ecology clean propellant. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 97-102. The technical paper about modernization of "Rocket Engine" department fire stand for investigation of working process of liquid rocket engine of small thrust on ecology clean propellant. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Anisimova T. V., Danilina A. N., Kryuchkov V. V. Methods of increasing quality of output voltage for inverters with step output waveform. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 103-112. This paper is devoted to the comparative evaluation of the two modulation strategies developed for multilevel inverters control: the harmonic elimination technique with voltage control (OHSW) and the optimal minimization of the total harmonic distortion method (OMTHD), which are a very important and efficient strategies of eliminating sel ected harmonics fr om spectrum of the output voltage or minimizing its total harmonic distortion in order to improve its quality. First, we describe briefly the basic idea and concept of each technique. Then, we present a study of the performances of each one by the means of a comparison between them. Simulation has also been presented to establish the effectiveness of the proposed analysis. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lapushkin V. N., Novikov A. V., Rodchenko V. V. Thermodynamic study of the characteristics of small-size centrifugal compressor turbojet disk gtj using solidworks cad package, and mathematical modeling of cosmos. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 113-119. Article deals with the possibility of using modem computer technology in the design of small gas turbine disk motor-generators for the analysis of thermodynamic processes on the highway the engine in a small amount, in the example simulation of a centrifugal compressor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krahin O. I., Zenin V. A., Fatyanov S. A. Thermomechanical engines and power plants based on shape - memory alloys. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 120-130. The publication focuses on some questions about calculation and design of thermomechanical engines and thermal power plants developed by alloys with shape memory. Also, some requirements for the alloy defined when it is used as an active element (actuator) in thermomechanical engine and in the power plant. Next, there goes classification of active elements and recommendations for its selection for the maximum efficiency and adaptability. There are also given some fundamentals of design of thermomechanical engines with active elements based on alloys with shape memory, then there goes engineering method for calculating the thermomechanical engine. Finally, there goes a theoretical researching of special type power plant turbine working in two environments (water-air) and the possibility to create an installation of this type. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Terentyev V. V. The choosing of collaborative product development chain in a knowledge - based -system. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 131-135. The paper formulated the following possible method of development engineering products: 'find the optimal Collaborative Product Development chain (CPD chain) in the information infrastructure". The method focuses on the collective distributed work with complex, hierarchical structures, with large amounts of heterogeneous information. An algorithm for implementation of the method applied to the problem of estimating time and material costs for the engineering project. In paper defined the tasks of development an expert system for criteria! evaluation the sequence of realization mechanical engineering project. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Medvedskiy A. L., Kurbatov A. S. Investigation of stress-strain state building carbon-carbon composite materials with technological defects. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 136-139. The article offers the generalized approach towards software modeling which is based on interaction graph. The given approach allows to define notation and to represent a software system according to set notation. Notation can be extended to promote detailed description. Interaction graph provides the combined usage of different models without any restriction on technologies applied during software development. The explanation how this approach can be used to represent a software system in different notations is also described in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostyukov V. M., Merkuliev A. M. Comparative analysis of effectiveness of employing complex measurement processing algorithms in aircraft control system. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 140-148. Task of estimating effectiveness of employing complex measurement processing algorithms in control system of the aircraft was considered. Solution of this task based on employing complex mathematical simulation was proposed. Three different complex measurement processing algorithms were investigated. Statistic simulation was carried out and descriptions of errors of estimation of status variables of aircraft were calculated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sudakov V. A. Management automation of enterprise application development. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 149-153. In this article some questions of enterprise applications developing management process automation are considered: process formalization, developing mechanism oflifecycle information collection, criterion of efficiency of software developers, OLAP technology application for strategic management. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sirotinsky V. V., Semenov D. V. The problem of productivity of enterprise data warehouse. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 154-159. Data warehouse foundation aspects are discussed in the article. Differences of OLTP-systems from the systems focused on the analysis of the data are described. Modern ways of optimization of productivity of analytical information systems are systematized. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Komarova N. V., Miuskova R. P. Optimization of organizational decisions in highly-technological manufacture for the purpose of labour productivity increase. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 160-164. In article optimization methods organizational decisions with use applied a mathematics, network and heuristic methods are stated. Recommendations about application of domestic base system of microelement rate setting of labour as measuring toolkit for an estimation of the existing organization of work and designing of optimum organizational decisions in highly technological manufacture are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mikheyeva L. S. Mechanism of formation program of organization development management system for enterprise radio-industrial complex of Russia. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 165-170. Radio industry is an important system-branch of the economy of Russia. Economic reforms are carried out in a crisis situation in the native aviation and space industries in Russia. Creating the mechanism for the formation of organization development control system enterprise of radio-industrial complex will allow optimizing the controlling system of the enterprise. As a resulte the optimization of controlling system will be achieved improving the performance of the entire enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panagushin V. P., Chaika N. K., Klonitskaya A. Y., Gusarova Y. V. Perfection of legal and economic base for reduction of the unprofitable organisations of the aviation industry. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 171-175. By-laws were amended by the introduction of proposals on redaction of unprofitable enterprises in aircraft industry for recovery of their solvency and financial sanation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fomkina V. I., Kolosov I. M. Distinguishing features of budgetary planning in foreign economic activity of aviation company. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 176-180. The derivative financial instruments is presented in the article to manage an consolidated budget enterprise. A developed technique is based on the hedging of foreign currency with usage the derivative instruments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Medvedskiy A. L. Dynamics of non-uniform transversal-isotropic spherein the acoustic environment. Aerospace MAI Journal, 2010, vol. 17, no 1, pp. 181-186. In work the problem about radial fluctuations hollow elastic non-uniform transversal-isotropic sphere placed in the unlimited acoustic environment is considered. It is supposed that heterogeneity of a material of sphere is described by the sedate law concerning radial co-ordinate. The problem decision is under construction with use of integrated transformation ofLaplas on time. For a finding of originals it is used асимптотика трансформант in a vicinity of infinitely remote point of a complex plane that corresponds to initial times of interaction. Comparison received асимптотики with the decision constructed with use certainly scheme of type oj Kurant — Izakson — Rice [1] is spent. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isaev V. K., Zolotukhin V. V. Some problems of 2D-maneuvering to ensure the vortex safety of an aircraft. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 5-10. The generalized parametric model is given to calculate the evolution of vortex wake behind an aircraft. Using this model the method has been developed for correcting the trajectory of the aircraft during its movement in a vortex wake behind an aircraft-generator. We consider two types of flat-plane maneuvers of an aircraft-follower with subsequent returning to the original trajectory: in the vertical and horizontal planes. An algorithm has been developed to ensure the vortex safety of an aircraft-follower using criterion of minimum deviation of an follower of the original trajectory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aksenova O. A., Khalidov I. A. Influence of gas atoms scattering parameters on a surface on flow stability. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 11-14. It is shown, that rarefied gas flow instability (that could be observed as variation of flow regime by a small deviation of the parameters) can remain valid in different flows. The regions of parameter variation are found, corresponding to different types of attractors (stationary attraction points, limit cycles, infinite cascades of bifurcations and chaotic attractor). The results could be applied to rarefied flows in channels and nozzles in flying space vehicles, as well as to small-scale flows in very narrow channels (near to molecular scale), where Knudsen number is large at normal atmospheric pressure. Active interest in these flows is caused by practical importance of microelectric systems as well as by development in nanotechnology. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bedarev I. A., Fedorov A. V. Numerical investigation of detonation initiation in shock waves. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 15-22. In the work numerical simulation of formation and propagation of a detonation wave in a reacting mixture of hydrogen and oxygen is presented. One-dimensional non-viscous and two-dimensional viscous flows of a reacting mixture are investigated. As mathematical model gasdynamics equations are implemented, taking into account heat generation at the expense of chemical reactions. Various detailed kinetic schemes are applied for the chemical transformations' modeling. Adaptive grids were implemented for the numerical technique. Mathematical model and numerical algorithm are verified on experimental data and some tests. Influences of 2-D and viscosity on detonation parameters in case of a detonation initiation in reflected shock waves are analyze. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov I. E., Kryukov I. A. Numerical investigations of turbulent flows with free and restricted shock separation. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 23-30. The article is devoted to numerical study of separation of turbulent boundary layer from nozzle wall for supersonic viscous flow. Interaction of shock wave with boundary layer is studied mainly for internal flows. Flow in plane, cone and profiled axisymmetric nozzles is considered. Detailed study of flow structure and some its parts (separation, mixing, reattachment, recirculation flow) is performed. Space-time correlations between flow parameters in different flow zones are investigated. Conditions of realization oj restricted and free shock separation in profiled nozzles, hysteresis of separation type during increasing or decreasing entrance pressure, possibilities of control of separation type and location of separation point are studied. Numerical simulation of turbulent flows in dual bell nozzles is considered for wide external pressure range. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pirumov U. G., Shustov S. A., Gidaspov V. Y., Ivanov I. E. Basics of physical gas dynamics of nozzles and jets of rocket microthrusters. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 31-42. Physical statement of a problem about modelling gas dynamical processes in nozzles and jets of Rocket microthrusters taking into account their nonideal flows is stated. The description to the mathematical formulation of a problem received on this basis and the developed numerical algorithm of its decision are implemented in the form of a program complex. Results of approbation of the developed numerical model, showing its adequacy are stated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Veitsel A. V. The new class of binary offset carrier signals for navigational system. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 43-48. The new class of meander pseudorandom signals for radio navigating systems is offered. The new class of signals is based on the BOC-signals. The method of formation of a new class of signals and their characteristics providing compatibility with existing signals and possibility of realization of broadband signals on their basis is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerko S. A., Sorokina I. A. Application of increases of pseudophases at relative determinations of moving objects on signals GLONASS and GPS. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 49-56. In article experience of application of increments of the first and second differences ofpseudophases in a problem of relative definitions on signals ofSRNS GLONASS and GPS is considered. The basic achievement of the applied approach is the increase in right ambiguity resolution of phase measurements at relative definitions of two mobile receivers. Results of tests with use of real measurements of navigating receivers are resulted. Tests were spent as on signals ГЛОНАСС and GPS separately, and at the combined mode. The given experience can be useful at the decision of applied problems, for example, problems of definition of spatial orientation, management of relative movement of several objects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karpuhin E. О., Vitomsky E. V. Applying of filtering technology in the design of secure communication systems. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 57-60. Results of the analysis of software technologies used in the development of host-based firewall on OS MS Windows. Descriptions of method of developing software tools for technology-based Filter-Hook Driver, enhances the effectiveness of the development and maintenance of industrial firewall. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tkachev A. B. Research of correlation properties of sequences for signals with code division of system GLONASS. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 61-66. In article consideration of correlation properties of various binary sequences which can be applied to signals with code division in system GLONASS is spent. The analysis of sizes of correlation functions lobes of these sequences is carried out both at absence, and in the presence of frequency shifts between signals. Also sizes of the lateral lobe of autocorrelation function nearest to the main maximum are considered. The choice ofparametres of Weil codes minimising this size is made. The Weil codes providing the least multipath error are found. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakalov V. P., Nuzhdin V. M. The estimation of antenna diagram of panoramic radar of radar image of earth's surface. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 67-69. The technique of the estimation of antenna diagram of the panoramic radar on the basis of the radar image of district is created. The technique allows to refuse labour-consuming direct measurement and provides sufficient accuracy for practical appendices. Results of modelling and the estimation of antenna diagram on the basis the real radar image are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ignatskaya I. V., Lukin V. N. Interaction Graph Software Modeling Conception. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 70-75. The article offers the generalized approach towards software modeling which is based on interaction graph. The given approach allows to define notation and to represent a software system according to set notation. Notation can be extended to promote detailed description. Interaction graph provides the combined usage of different models without any restriction on technologies applied during software development. The explanation how this approach can be used to represent a software system in different notations is also described in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kibzun A. I., Panarin S. I. Stochastic model of alterability of remote education system. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 76-79. This article considers distance learning system CLASS.NET, that has been created by the authors. Analyzed system's important property — modi/lability, that is necessary for rapid implementation of the new requirements. Introduced the stochastic model of modiflability and a new approach, which enables to find the optimal parameters of the system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kichinskiy K. A., Reviznikov D. L. Practical approaches to the design and development of scientific and educational distributed Internet applications. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 80-89. Different technical aspects of the designing and development of scientific and educational internet-applications using modern web-technologies and RIA-technologies are discussed. Practical approaches are presented for the combining different types of solutions to aroused problems based on the consideration of the local application context. It is shown than RIA-technologies are potentially applicable to organize and run distributed online-computations on the web-browser side. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Say Khing Aung Tint . . Architecture and scenario of the education system. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 90-95. It is considered three-level WEB - the focused architecture of system of computer training and testing. Assumes storage of a didactic material and the metadata on a server of databases, remote access of users to system through the Internet/ intranet, processing of results and realisation of adaptive management by process of training (testing) on a server of appendices. Aspects of system are managing directors and validation rules of the scheduler which is intended for support of functions of the virtual teacher of each real user. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kindinova V. V., Kuznetsova E. V. System dynamics in simulation modeling problems for the dyopoly markets. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 96-103. The simulation model of the duopoly markets is presented. The model is designed with applying of System Dynamics technique in Anylogic modelling environment. The imitating Model allows to analyze a level of demand for the homogeneous goods of two contestant firms, to estimate rates of growth of incomes affirm and the competitor. Results of the computer experiments, reflecting the phenomena of a hysteresis and an avalanche, are analysed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krinetsky E. O., Shebeko Y. A. Imitating prototype for the competitive behaviour model of economic agents in the conditions of the limited volumes of renewed resources. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 104-109. The article offers the generalized approach towards software modeling which is based on interaction graph. The given approach allows to define notation and to represent a software system according to set notation. Notation can be extended to promote detailed description. Interaction graph provides the combined usage of different models without any restriction on technologies applied during software development. The explanation how this approach can be used to represent a software system in different notations is also described in the article. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golovanov A. I., Sultanov L. U. Computational investigation of hyperelastic solids using left Cauchy—Green deformation tensor. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 110-118. The article is devoted to analysis of hyperelastic solids using left Cauchy—Green deformation tensor. An incremental method is used. Stress state is represented by Cauchy stress. A general constitutive relationship is derived from the proposed strain energy. The finite element method with poly linear three-dimensional isoparametric approximation is applied. Numerical computations illustrate ability of the described approach and its program realization. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dmitriev A. I., Zolnikov K. P., Psakhie S. G. Numerical study of the kinematic properties of bilayered films of finite length and nanosclae thickness. Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 119-124. With use of molecular dynamics method the kinematic characteristics of non-closed nanostructures were studied. Nanostructures were formed from bilayer nano-sized crystalline films of Ni-Cu grown on the substrate. Interatomic interactions were described within the embedded atom method. It was shown that in case of sudden separation from the substrate the edges of non-closed nanostructures can make free harmonic oscillations. The dependence of the amplitude of oscillations of the size of the original film was investigated. The influence of the crystallographic orientation of the original film on the parameters of oscillations of non-closed nanostructures was analyzed. The results of simulation are of interest in the design of the components of nanodevices for various applications. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Koterov V. N., Yurezanskaya Y. S. Modeling of passive suspended substance dispersion on the oceanic shelf . Aerospace MAI Journal, 2009, vol. 16, no 7, pp. 125-131. Suspended poly disperse substance dispersion in a water body is simulated in the case when the spread area is considerably larger than the depth of the water body. The efficient two-dimensional methods is developed taking into account interactions between bottom and substance, substance faction index and vertical source position. Stochastic discrete clouds method is suggested taking into consideration «4/3 low». This method combines the advantages of stochastic discrete particles method and discrete clouds method. Stochastic discrete clouds method is tested by the comparison calculation results and analytical solution for the model problem oj pollutant dispersion from time-continuous point source. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eremin N. A., Liseitsev N. К. The automation of airplane layout design for flying wing configuration. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 5-10. New approach to automation of layout design flying wing configuration of airplane is discussed. The process is realized on the base of comparative analysis of alternative airplane configurations. The configurations are results of reconfigurations of the base layout scheme. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ignatkin Y. M., Makeev P. V., Shomov A. I. Researches of aerodynamic characteristics of helicopter rotor on vortex ring state mode by nonlinear blade vortex model . Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 11-15. Article is devoted to researches of vortex ring state of helicopter rotor by nonlinear blade vortex model. Examples of vortex wake, flow lines, velocity fields and aerodynamic characteristics are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Artamonov B. L., Mojzyh E. I. System of the interactive analysis of the zone of the review through flight compartment windows of the flying device. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 16-28. The software intended for automated construction and the comparative analysis of a zone of the flight compartment view oj space from the possible locations of the pilot ofaircrafts is considered. A basis for construction of borders of a zone of the review are virtual parametrical models of a cabin and a workplace of the pilot, executed on the basis of system of solid-state modelling SolidWorks. The developed system allows to carry out in an interactive mode the analysis of layout and technological decisions oj shape of a cabin and glasing at all design stages of life cycle of aircraft and to provide conformity of borders of an actual zone oj the flight compartment view spaces to normative requirements of aviation ergonomics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Maslov A. D., Krivolutsky Y. V. Method of the structure formation and number of the helicopter fleet on the basis of the predictive region development models. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 29-33. It is developed the method of the structure formation and number of the helicopter fleet on the basis of aerial work content, structure and characteristics, which helicopters support in the hand-picked region over a predictable period of time. As a case in point it is defined the structure and number of the prospective helicopter fleet, that supports execution forecast aerial work contents in Tyumen region. The helicopter operating cost of the examined models is specified. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pravidlo M. N., Zhuravlev L. I. On methods of developing and comparison mathematical models of aviation ejection launchers. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 34-38. This article is dedicated to modeling problems of dynamics of aviation ejection launchers. An analysis of existed approaches to mathematical models development for ejection launchers is carried out. A method is suggested to its modeling, based on using numerical method of computation coefficients of Lagrange equation of 2-nd kind and on mathematical model comparison based on ejection launcher's ground testing results. Comparison problem is viewed as dynamic system comparison problem. Method of comparison with reference model is used there. Provided results of comparison with developed method use showing good modeling results convergence with results of ejection launcher's ground testing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kravtsov V. A. The finit element models of slide composite material. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 39-42. Some existing types of composite material units models for calculation with Finite Element Method are described. The developed model for increase accuracy of units analysis made of composite materials in irregular zones is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volkov V. N., Gusev A. N., Ivakha V. V. Heat-loaded trajectory selection for durability valuation of aviation guided missile airframe. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 43-48. The article devoted to heat-loaded trajectory selection for durability valuation and ground-based test execution of aviation guided missile load-bearing unit elements. The introduced approach allows selecting material of aviation guided missile load-bearing unit elements with durability assurance in all service conditions at projecting phase. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pychkov A. M. Criterions and computation method of distributed control signals limitations for flight-apparatus rule drives. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 49-54. For unmanned flight apparatus executive machinery and ruling drives are the same for any contour of angle control. In this paper the problem of qualitative and correct control signals for ruling drives distribution is considered and solved. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveev Y. A., Lamzin V. V. Optimization of parameters of earth remote sensing space system taking into account the features of spacecraft designer decisions. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 55-66. The method is considered for comparative techno-economic alternative analysis of project solution Earth remote sensing (ERS) space systems. The method is allowed to define influence of external and internal parameters of summary cost ERS space systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kartovitsky L. L. The fan mathematical model for off-design regimes to estimate its acoustic power. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 67-73. The development algorithm of the mathematical model, estimating parameters of subsonic and transonic fans is considered using optimization for off-design operating regimes with the purpose to estimate the noise power for low pressure compressor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Agul'nik A. В., Onishchik I. I., Htay T. M. Self-empirical simulation of combustion efficiency and combustion flame stability for Gas Turbine Engine. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 74-81. This is the result of semi-empirical algorithms calculation of combustion efficiency and stalling characteristics of the typical combustion chamber of Jet engine (puc.l), based on generalization of the experimental data resulted in the scientific and technical literature. In algorithms use relative parameters of combustion chamber which have been not connected with its absolute sizes are used. This results of the settlement analysis of influence of some design data of the chamber and operating modes on its characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nesterenko V. V. First principles of methodology of integrated optimization of image and parameters in hot section of gas turbine turboshaft engine. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 82-92. The article is related to problems of integrated development ofturboshaft engines with axial-centrifugal or centrifugal compressor, rotary combustion chamber and axial-flow turbines of gas generator and power turbine with various cascade numbers. Criteria which define the choice of gas generator turbine and power turbine cascade number and construction arrangement are investigated. Development of inter-turbine transfer channel with minimal losses of gas energy and high level of gas dynamic stability on the base of experimental characteristics and criterial dependences of different versions ofdiffuser ring channels is examined. In conclusion, the advices for the choice of main parameters at development ofturboshaft gas turbine engines in power range 300... 3000 hp are given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Amelkin A. S., Kiansky T. N., Ravikovich Y. A. The physical model of intershaft bearing working in off-design conditions. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 93-97. This article describes the physical model of high pressure turbine intershaft bearing of aviation bypass engine working in off-design conditions. The origin of initial damage of the intershaft bearing, factors that influence the initial damage rate and probable consequences of the defect formation are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuprukhin A. A., Nikitin P. V., Sotnik E. V. Experimental definition catalytical and radiating properties of materials of heat shield of space flying apparatus . Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 98-107. In article the method of experimental definition catalytical and radiating properties of perspective materials of heat shield oj space flying apparatus (SFA) of the planning class is stated. The method is developed with the purpose of use on high-temperature gasdynamics stands reproducing natural thermal parameters at flight of SFA in an atmosphere of the Earth and other planets. The analysis of influence catalytical and radiating properties on heat exchange on surface SFA is carried out. Algorithms of experimental definition of these properties are offered. Importance of the results stated in work is supported with that fact, that catalytical and radiating properties appear the unique factor, capable to reduce a supply of heat to a surface of a space vehicle at flight in dense layers of an atmosphere with hypersonic speed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kirillov V. Y., Tomilin M. M., Gordeev S. V. Research shields characteristics of flexible material. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 108-110. The article describes results of research characteristics flexible material to detection possibility of application for protection electronic elements and units from electromagnetic interference arise from electrostatic discharges. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlova N. V., Lunev E. M. Software and algorithmic maintenance for definition of navigation parameters of the unmanned aerial vehicle on the basis of photographic image. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 111-119. This article examines the possibility of definition of navigation parameters for an unmanned aerial vehicle on the basis of the ground-based objects photographic image. The algorithm of calculation of navigation parameters based on known coordinates of the displayed ground-based objects on image is presented. The modeling results which have confirmed the possibility of use of this method are provided. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Milyutin D. S., Veitsel A. V., Nikitin D. P. Use of new signals of satellite navigating systems for improvement of position accuracy. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 120-124. One of the basic errors of definition of position in satellite navigating systems — a multipath error is considered. Calculation oj multipath error for various signals taking into account frequency characteristics a radio path is resulted. Bending around multipath errors for various BOC-signals are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Glazkova I. A., Malyshev V. V., Darnopykh V. V. Estimation of perspective micro-satellite Earth observation system efficiency on the base of imitative modeling. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 125-134. The problem ofa-priory estimation of a perspective Earth observation system functioning is considered at the article. The orbital segment of the system is based in 5 micro-satellites. Five variants of orbital segment are researched and adapted scenarios of target functioning are offered also. These scenarios allow to apply a method of imitative modeling for system efficiency estimation. The results of modeling are presented and analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goncharenko V. I. Method of reflection and rating visibility settings of ballistic missiles' trajectory. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 135-142. Method of examination visibility settings of ballistic missiles' trajectory is offered, based on using mathematical models of ballistic missiles' trajectory. The characteristics of mathematical model of BM's trajectory are realization, which is created by Nustrem 's modified integration method. The use of this method is shown to make a research of visibility settings of ballistic missiles'trajectory from given points of observation for calculating conditions of situation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybalko A. A. The modeling of cloud service provider network defence systems with virtualization elements. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 143-149. The following work is dedicated to modeling the perimeter network security systems of datacenters. The work is focused on the usage of virtualization mechanisms to provide protection of web servers and cloud based applications. A base analysis is made oj methodology and instruments chosen for the task. Also, the UML programming language is used for making the basic modeling: use case diagram, sequence diagram and the state diagram. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sheval V. V., Krylov I. G. Comparative experimental and imitating researches of automatic landing of a pilotless aircraft. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 150-154. The technique of joint complex natural and imitating tests of a control system of low-sized pilotless aircraft (LSPA) is presented. Features of the rational coordination of the results received on mathematical model, with formation of the program of carrying out of natural experiments and with parameters of the law of management of carrying out of automatic landing LSPA are shown. The assumption of the general character of the offered technique is come out. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Fomkina V. I., Nikulina E. N., Tarasova E. V. The characteristics of the financing investment activity of the aviation enterprises. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 155-159. There are revealed financing sources of investments in aviation industry. The advantages of using different forms of credits are detected. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kalakutina E. Y. The features of crediting companies in aviation industry. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 160-163. The problems of organizing the crediting of companies in aviation industrial complex in Russian Federation were examined. The specific features arising at crediting in defense industry complex were marked. Possible variants of loan raising depending on the borrower's problems to be solved were shown. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sadchikov I. I., Chulcov S. A. Substantiation of rational flight multiplication factor of using rocket engines and glider in the system's perspective reusable launch vehicles of payload in orbits. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 164-170. This article presents the estimation of rational flight multiplication factor of using propulsion system and glider in the system oj perspective reusable rocket on criterion general costs and production output in view of safety launch vehicle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Novikov A. N., Pronkin N. N. Information maintenance of financial management of corporations in aviation industry. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 171-174. A new view of possibilities of usage of information technologies in enterprise resources management in aerospace industry according to the continuous management integration process in all chains and levels of the industry is proposed in the article. The authors inquire the questions of practical realization and evaluation of efficiency of using modern information technologies in order to increase the quality of decision-making in financial management of aerospace industrial enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Levin V. A., Smirnov S. V. On the properties of internal trapped waves in a model of ocean dynamics. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 175-181. The effects of viscosity and spatial finite-differencing on internal coastal trapped waves in numerical models are investigated using thef-plane shallow-water equations approximated on Arakawa В grid. Semi-infinite model basin of constant depth is bordering a straight, vertical coast. No-slip boundary conditions are considered. The solutions are presented for some «typical» values of model parameters. We found, that together with the Kelvin wave, an additional short wave solution propagating in the opposite direction appears. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y., Severina N. S. Numerical simulation of experiments by definition of time of the delay of ignition in shock tubes. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 182-192. The physical and mathematical model and the computing algorithms intended for numerical simulating of distribution of stationary detonation waves in shock tubes are resulted. The gas mixture of hydrogen with the oxygen, diluted with argon is considered. The settlement way receives detailed structure of the recompressed stationary detonation wave in a shock tube. Results of comparison oj calculated times of a delay of ignition with experimental data are resulted. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinnikov V. V. Algorithmic description of ghost-cell immersed boundary method. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 193-198. This paper considers aspects of algorithmic description and program implementation of implicit ghost-cell immersed boundary method for solving heat transfer and aerohydrodynamic equations in complex geometrical domains with curvilinear boundaries on rectangular grids. Detailed description for solving Laplace equation in domain with curvilinear boundary is provided. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abgarian K. К., Bazhanov D. I., Kholomeeva A. A. Density of electronic states of some perovskite-like structures forecasting by the example of CaTiO3. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 199-203. In the given work the algorithm of forecasting of density of electronic states of any crystalline material, proceeding from bases of the quantum theory, together with algorithms of construction and an estimation of stability of crystalline structures and their property which have been earlier developed and described in our works is described. In article by the example of well-known perovskites it is shown, how, using for calculations only the standard data about the elements entering into investigated structure, and assumptions about symmetry type of crystalline structure, possible to predict not only atoms positions in a standard crystalline cell, but also to define parameters of a cell and density of electronic conditions of substance precisely. Perovskite CaTiO3 is studied in detail from the point of view of its electronic structure. These approaches could be applied for creation new materials for aviation and space-rocket fields. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Artemiev A. Y. Rapid error-bounded simplification of a 2.5-dimensional triangular mesh. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 204-212. The article describes a method for the rapid error-bounded simplification of a 2.5-dimensional triangular mesh. The algorithm presented preserves geometrical features of a surface within the given error bounds. Some method applications include post-scan mesh processing in range scanners, terrain models simplification, mesh processing in network applications. The algorithm also supports concurrent computing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dmitriev S. S., Kuznetsov E. B. Application of discrete continuation for solving systems of differential-algebraic equations. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 213-221. Problem of analyzing of durability of aviation and rocket-space constructions subject to creep of material may be reduced to numerical solving of systems of differential-algebraic equations with delay argument. Approach for solving systems of differential-algebraic equations, based on discrete continuation along the best argument is considered. Error estimation of solution of the system of nonlinear equations by Newton's method is obtained. System that describes process of vibration-drilling is solved via this approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N., Inflianskas V. V. Algorithm of evaluation of convergence of solution in finite-elemetal problems. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 222-227. We have considered two basic cases of the convergence of solution infinite element problems. An algorithm has been given to evaluate point-by-point convergence of solution for local finite element mesh refinement. To illustrate the method the results of cylindrical three-layered composite shell computation under the action of local load have been presented. For stresses reaching maximal value in loaded area, we have determined parameters of mesh density producing converge solution. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Petukhov A. A., Reviznikov D. L. Algorithms of numerical solution of fractional differential equations. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 228-234. Some problems of numerical solution of fractional differential equations for anomalous diffusion are considered. Numerical algorithms are presented for the equation with fractional derivatives in time and space. Analysis of stability and approximation is carried out for developed explicit and implicit schemes. It is shown that the numerical results are in good agreement with exact analytical solution. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V. Method of calculation dynamic and stress-strain state of an aircraft skin at action muzzle shock wave. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 235-243. The method and algorithm of calculation of the dynamic and is intense-deformed conditions of the panel of an aircraft skin, being in immediate proximity from a cut of a trunk and subject to influence a muzzle shock wave is considered.
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Vestyak V. A., Zemskov A. V., Erichman N. N. Numerical-analytic solution for inverse quotients thermoelasticity problem for a plate. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 244-249. An inverse quotients thermoelasticity problem for a finite thickness layer is considered. The proposed solution is based on the assumption that thermo--mechanicalprocesses in the layer have a stationary harmonic character. The area geometry and boundary conditions allow reducing the problem to a one-dimensional thermoelasticity problem. Assuming thermomechanical oscillation frequency small enough a solving equation was produced. This equation allows determining quotients of temperature stresses and heat release under deformation. Obtained results can be used to simulate the process of experimental determination of physical-mechanical properties of the materials used in aero- and spacecraft manufacturing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korshikov S. B. Object selection for fast calculation of CAD documents hash. Aerospace MAI Journal, 2009, vol. 16, no 6, pp. 250-251. In this article we are reviewing method of fast calculation of CAD documents hash. This method based on information selection from model document, that reduce time for making document's digital signature and authentication against it. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Ivanov N. A., Kolesnikov V. A., Mednov A. G. A technique to evaluate temperature dependences of thermal and physical characteristics for anisotropic materials basing on an inverse problem solution . Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 247-254. Algorithms and software are developed to analyze thermophysical characteristics of anisotropic materials basing on a solution of inverse heat conductivity problem stated as an extremal one. An efficiency of the technique is demonstrated as applies to a recovery of the thermal conductivity tensor and volumetric heat capacity basing on physical experiment results. The recovery is carried out for an orthotropic material built on carbon fibers and epoxy binder. This material is promising for design of aerospace structures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baranov V. N., Zaw L. O. A post-flight analyses technique to support flight tests of light aeroplanes. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 195-200. One of actual contemporary scientific and engineering problems is design of light airplanes intended for monitoring of natural and technogeneous disasters. Flight test is very important step in design process for any aircraft including light one. Aerodynamical and other characteristics are revealed and refined by means of flight test. Proposed two step scheme for solving the problem on the basis of preliminary processing of transients and the use of the method of least squares, follow by the final processing of information using the Kalman filter | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Popov S. A., Ignatov N. E. VT-1 MAI vertical wind tunnel design. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 5-16. Survey of existing free fall simulators is presented as well as a market analysis of the area. A design problem for vertical-flow wind tunnel is formulated basing on cost-effectiveness and safety requirements. Some ways are proposed to solve this problem. The suggested technique can be used to develop subsonic vertical-flow wind tunnels. Some aspects are analyzed to shape working section of the tunnel, to choose and design the optimal axial fan, to match operating modes of the fan with electric motor characteristics. General arrangement and overall view is presented for the designed VT-1 MAI vertical-flow wind tunnel. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Prilipov A. V. An improvement of energetic and mass performance indexes for gas-hydraulic drive systems with displacing power source. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 40-45. The Solving of the developing task of energy efficacy performances of gas-hydraulic drive system with displacing power source in the mobile objects control aims | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Poliansky V. V., Nesterov V. A. Estimation of reliability alteration for airframe configuration with mechanical damage. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 32-39. In work results of reliability alteration analysis ofpilotless aircraft with mechanical damage are represented. Variant of aircraft movement in ground terrain rounding mode is examined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ignatkin Y. M., Makeev P. V., Grevtsov B. S., Shomov A. I. A nonlinear blade vortex propeller theory and its applications to estimate aerodynamic characteristics for helicopter main rotor and anti-torque rotor. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 24-31. A technique is presented to analyze aerodynamic characteristics of helicopter rotors basing on nonlinear blade vortex theory taking into account vortex diffusion. Basic features of the suggested model are discussed as well as possible applications of the model. Some investigation results are demonstrated for rotors at various operation modes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stepanov V. D. A procedure of optimal discrete synthesis for aircraft complexes basing on their formalized morphological analysis. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 17-23. Optimal synthesis problems are considered for aircraft complexes assembled from units belong to a finite set of alternative subsystems. A statement and solution technique are suggested for the synthesis problem basing on optimal decomposition of the aircraft complex into groups of closely linked subsystems. Main principles are suggested to analyze morphologically the aircraft complex. Simulation results are presented as applies to a foundation of conventionally optimal updating ways for hypothetical aircraft complex of tactical aviation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bykov A. V., Parafes S. G., Smyslov V. I. Hardware and software tools for computational and experimental investigations of aircraft aeroelastic stability. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 56-63. A firmware inclusive software and equipment for excitation oscillation and data acquisition in laboratory conditions is considered. The firmware provides experimental, calculated and experiment-calculated investigations directed to determination of natural oscillations, frequency response of system stabilization, as well as solution of flutter and aeroservoelasticity problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lamzin V. V. A performance investigation for optical-electronic Earth remote sensing system during planned upgrade. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 46-55. The influence of parameters and realization project program for techno-economic characteristic of Earth remote sensing (ERS) space system are researched. An example is given to demonstrate effective updating process for the some ERS space systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilyev Y. В., Gatsenko L. S., Evdokimov K. V., Svotina V. V., Semenov Y. A. A modeling of processes in cascade photoelectric transducers. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 123-130. Cascade photoelectric transducers are presented as well as operational performances of GaAs heterostructures intended for spacecraft. A physical and mathematical model is suggested for cascade photoelectric transducers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shcherbakov M. A., Yun A. A., Krylov B. A. A comparative analysis of turbulence models using Fastest-SD scientific code and ANSYS СFХ commercial software package. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 116-122. A flow simulation is presented for a 2D channel with different Reynolds numbers (Re = 5600, Re = 13750). Additionally a parametric analysis is carried out for different meshes depending on various Reynolds number values. Computational experiments are carried out to compare the ANSYS CFX and Fastest-3D software packages. The k-Ј, k-o, SST, low-Re WJ and low-Re CLS EARSM turbulence models are used in the experiments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shtyrlin A. F. Charged-particle beam acceleration and energy efficiency of colloid electric propulsion thruster. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 111-115. Necessary conditions are examined to achieve thruster working medium velocity in the range from 3 to 30 km/sec. Charged particles motion in the thruster beam was studied according electric field distribution in the single thruster cell volume. Thruster effectiveness is estimated numerically taking into account its energetic efficiency. It is found out that for voltage varied from 3 to 3d kV the acceleration efficiency is changed in the range from 0,5 to 0,9. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Skorohod Y. Y., Shergin V. E. An analysis of converter input power circuits for advanced aircraft electrical systems. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 101-110. An analysis is carried out for input power circuits and control algorithms to stabilize voltage in advanced aircraft electrical systems operating with higher voltage level. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Butrimov D. L. A numerical investigation of transonic compressor cascade characteristics for modern gas-turbine engines. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 92-100. A computational technique is described to solve Reynolds averaged Navier-Stokes (RANS) equations. Procedures are presented to obtain faster steady-state solution of the RANN. Numerical aerodynamic simulation results are presented as well as analysis results for parameters of a transonic cascade. A possibility is demonstrated to change flow structure and to improve aerodynamic characteristics of the transonic cascade. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gridin V. N., Kvasnikov L. A., Sawin V. L., Smakhtin A. P., Chuyan R. К. Wireless power engineering as a basis for development of global power networks. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 87-91. It is well known that the European Union accepts energy problem as one of the five vital world problems together with water, public health, agriculture, and biological diversity problems. Process of power transmission from an energy generator to an energy consumer is one of important links included into full power engineering process. A new power transmission method is discussed. It is based on focused microwave and optical electromagnetic radiation beams. This method is capable potentially to solve some traditional and essentially new engineering problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karasiov V. N., Kartovitsky L. L., Levin V. M. Some organizational aspects for working processes in a ramjet combustion chamber. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 78-86. Some organizational aspects are discussed for working processes in a ramjet combustion limited-size chamber. Methods are examined to compress, ignite, stabilize flame as well as to combust a liquid hydrocarbon fuel in the chamber to obtain effective working process in the short channel with moderate total pressure losses. Experimental results are presented to demonstrate combustion of kerosene in the ramjet combustion chamber. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko A. N., Kulikov N. I., Sorokin A. E., Starovoytova N. P. Converter-fed motors with slotted and smooth-core armature for high-precision electric drives. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 73-77. An integrated comparative analysis is carried out to reveal specific indexes for converter-fed motors with slotted and smooth-core armature. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M., Yanyshev D. S. An analysis of hydrodynamics and heat transfer for unsteady turbulent flow in aircraft power plant channels. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 64-72. A survey is presented for current status of hydrodynamically unsteady turbulent flow modeling in channels as well as some results obtained to date. The hydrodynamically optimal shape of flow acceleration curve is derived. An analytical solution is obtained for the Prandtl friction ratio equation. Numerical simulation results are provided for turbulent flow in a circular pipe using modem turbulence simulation techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ershova T. V., Nikitin P. V. Thermo-erosive destruction of heat-protective materials in supersonic heterogeneous flows. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 135-143. An analysis is carried out to study influence of heterogeneous incident flow poly dispersity on thermo-erosive destruction for heat-protection materials. Obtained results indicate possible interference between temperature fields under the influence of various-sized particles. It is shown that incorporation of smaller particles into heterogeneous flow carrying large particles causes a reduction oj total destruction speed for the heat-protection material. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shishkin S. S. On calculation of leak tightness of rivet joints. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 131-134. A technique is suggested to analyze leak tightness for aircraft rivet joints with complete contact between plate surfaces and rivet shank. The technique is based on the theory of a porous layer. A simple procedure is discussed to calculate the contact pressure in a rivet joint according to the theory of small plasto-elastic deformations basing on direct measurements of component deformations in plates. It is revealed that in domain of real-world process variables for rivet joints leak tightness is determined by height oj microroughnesses on the hole surface. The contact pressure value is demonstrated considerably smaller influence the leak tightness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kulyba Y. N., Turuk V. E., Pappe G. E., Egorov A. A., Kirpichev K. U., Neretin E. S. An automated workplace for characteristics measurement and testing of microwave signal delay device intended for synthetic-aperture radar. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 149-158. A development of universal automated workplace is discussed to test microwave signal delay devices (SDD). The workplace allows us to accomplish tests of various electronic devices operating in microwave frequency range. A signal simulator and power control unit is suggested which is intended for attenuator integrated into the SDD. It is intended also to generate control signals to switch various channels of synthetic-aperture radar switching and to detect control signals. Experiments are controlled by means oj specially developed software packages named as Automated Workplace for SDD- Testing, which is based on the Wonderware System Platform and the InTouch SCADA-system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dudchenko A. A., Lur'e S. A., Shumova N. P. Some specific features of a resin in the neighborhood of rigid nanoparticle. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 144-148. Analytical expressions are derived to describe changes of elastic modulus for a media in the neighborhood of rigid nanoparticles taking into account their sizes and arrangement. These expressions are based on previous results related to a model ofinterphase material layer with rigid inclusions under tensile loads. Estimations are suggested for varying values of the Poisson ratio, and shear modulus as well as for a strength of resin in area adjoining to the particle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mordasov K. A. An evaluation of potential noise immunity of a decoding algorithm for pseudo-random codes based on passive matched filtering. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 166-170. An algorithm is suggested to decode rapidly long pseudo-random codes. An analytical estimation is considered for a potential noise immunity of the algorithm. Computer simulation results are presented for the algorithm operating in discrete symmetric channel using simplex block code (1023, 10) generated by means of circular shifts for one period of linear recurrent sequence with maximum length. The simulation results are compared with analytical ones. The comparison demonstrates a necessity to improve the pseudo¬random code decoding algorithm to reveal its useful potential capabilities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakhtin A. A., Popov L. A., Smirnov A. V. An implementation efficiency of cross-layer interaction for fast routing protocol in wireless ad-hoc networks. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 159-165. Methods are described to implement routing protocols ensuring effective communication at different levels of the Open Systems Interconnection (OSI) model without reducing throughput and increasing information transfer delays. A comparison is carried out between developed protocol and existing routing protocols for wireless ad-hoc networks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Darnopykh V. V., Kalashnikov A. I., Malyshev V. V. An optimization of observation schedules for an Earth remote sensing constellation by means of dedicated software tools. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 201-218. The optimization problem of operative planning for Earth observation system which orbital segment consists of several different (target functioning and parameters of special on-board equipment (devices)) spacecrafts (SC) is considered at the article. The process of the optimization is demonstrated as an order of special software application. One of the advantages of the software is the universality, i.e. possibility to solve the problem for any kind of Earth observation SC-constellation at any long-time planning interval. The example of optimization problem is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Levsky M. V. Optimal control problem for a fixed-time spatial spacecraft turn. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 186-194. Optimal control problem is discussed as applies to a fixed-time spatial spacecraft turn. A functional is minimized interpreting as a propellant consumption. An analytical solution is derived for the stated problem. The optimal solution belongs to a class oj two-impulse control. Under this control spacecraft turns along the so called free motion trajectory. The initial control problem is reduced to solution of three problems including acceleration of the spacecraft needed to reach the necessary angular momentum, uncontrolled rotation of the spacecraft, and damping of angular velocity. The complete solution of the reorientation problem in the closed form is given for dynamically symmetric spacecraft. This solution allows us to use the control method in practice. Simulation results are presented to demonstrate practical realizability of the suggested control algorithm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishin V. M., Phyo M. K. Reliability optimization for aerospace vehicle control systems using standby loaded redundancy. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 178-185. A method is suggested to increase reliability of control systems for aerospace vehicles under various failures. This method uses optimization of redundancy structure for standby loaded redundancy and it is based on reliability optimization algorithm and non-classical weighed edge graphs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krivilev A. V. A computer-aided analysis technique for a control word of mechatronic unit intended for electric drive with direct current motor. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 171-177. A technique is presented to analyze mechatronic unit control words basing on a modified adjacency matrix and constraint patterns. The technique allows us to find all possible control word states as well as all transitions between the states for an arbitrary switching method using key elements. Besides this technique reveals forbidden states and transitions for the command word which cause through currents. A description and implementation of the technique is performed by means of the Mathematica language tools. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moskvicheva N. V. An asset cost estimation for aircraft corporations under consolidation terms. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 242-246. The process of consolidation of aviation enterprises began in 2006, and it has not been completed yet. The advantages of mergers of enterprises are the industry's efficiency and a rational approach to spending of budget funds. Under the circumstances of the consolidation, appraisal of assets value of enterprises — taking into account their activities, analysis of their advantages and deficiencies — becomes of especial significance. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shchukina D. V. Taxation problems for closed end real estate investment trust and ways to solve them. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 234-241. Long ago real estate investment trusts became a part of investment world. Nowadays these trusts are the main part of global economy in whole and different countries economies in particular. Trust members taxation problem is one of the main factors braking elaboration of real estate investment trust in Russia. In the presented research peculiar properties of tax liabilities of real estate investment trust members are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Klochkov V. V., Nikitova A. К., Efimova N. S. Economic justification of major aircraft development areas as applies to unmanned aerial vehicles. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 224-233. Optimization techniques are suggested to solve family design problem for advanced patrol unmanned aerial vehicles (UAV). It is stated that UAV family members are intended for various customer kinds each of which has different payload requirements. The developed techniques are based on a simplified optimal demand model. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krugliayeva E. A., Korolev V. V. Economical framework of computer-aided logistics management for manufacturing of aircraft components as applies to on-board radar systems. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 219-223. An economical framework of computer-aided logistics management for manufacturing of aircraft components is presented as applies to on-board radar systems for a new generation aircraft. Major ways are discussed to realize information systems intended for manufacturing processes management as applies to development of this high-technology systems at main defense industry enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishanina T. V., Kwak J. . Application of the finite element method for calculation of nonlinear vibrations of a rotating blade. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 296-299. Mathematical model for calculation of vibrations of a rotating blade in the transverse plane is developed using the finite element method. The nonlinear and linearized equations of the blade vibrations are obtained assuming that the elastic blade axis is nonextensible. The calculation examples of the response are given for the absolutely rigid and hinged connections of the blade and the rotor hub in the case of kinematic impact on the hub. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shklyarchuk F. N., Yun H. S. Deformation of a skew four-beam box of a wing with variable sweep angle. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 291-295. Multi-level mathematical model is developed for calculation of deformations of a skew four-beam box of a wing with variable sweep angle using the section method. Estimations of the accuracy of the displacement approximations of the sections are fulfilled. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Konstantinov M. S., Min T. . A trajectory optimization method to solve a problem of spacecraft insertion into geostationary orbit using electric thrusters. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 282-290. This paper describes the trajectory optimization method for spacecraft insertion into geostationary orbit (GSO) with the use oj electric propulsion. Special efforts are made to provide regularization for the solving of the boundary value problems of optimal control. By applying the Pontryagin 's maximum principle, the low-thrust trajectory optimization problem is reduced to the boundary value problem for the ordinary differential equations system. The core sense of the boundary value problem is the solution of the non-linear system of equations. To solve the non-linear system of equations, we offer to use the hybrid method which combines the Levenberg — Markquardt method with the quasi-Newton method. We compare the effectiveness of this method with the use of the continuation method on parameter which offered in the works by V.G. Petukhov. The numerical results of the spacecraft's trajectory into GSO and the effectiveness of the electric propulsion application for such insertion are presented. Two factors are considered as the criteria of optimization — the time of flight (which is minimized for minimum-time transfer problem) and terminal mass of the spacecraft (which is maximized for fixed-time transfer problem). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bityukov Y. I. About parameters characterizing a ribbon laying scheme in winding process. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 274-281. A mathematical model is developed for winding with continuous fibers laying in the direction of acting force. This winding technique is one of the major manufacturing methods for products made of composite materials. Analytical expressions are derived to calculate parameters characterizing the winding process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makhrov V. P. Hydrodynamics of controlled flows with free boudaries forming by a ring type wing used as external hydrodynamic singularity. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 264-273. Some theoretical and experimental results are presented for axisymmetric cavity flows generated by a ring type wing. These flows are known as Lighthill-Shushpanov ones. They can be analyzed using the vortex singularity technique for «body-ring wing-cavity» combinations. A numerical solution of'integro-differential equations is carried out applying spline functions to cavities with with positive and negative cavity numbers. Experimental results demonstrate efficiency of the technique for cavity flows generation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Safronov V. S. Analytical stability estimation for a stiffened cylindrical shell with a hole under a complex loading. Aerospace MAI Journal, 2009, vol. 16, no 5, pp. 255-263. A technique is presented as well as appropriate theoretical investigation results/or stability problem as applies to stiffened cylindrical shell with a hole under longitudinal compression and external pressure. Analytical expressions are derived to solve this stability problem. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Orlov V. V. Effectiveness criteria generation for shipboard fighters in regard to air defense missions. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 5-7. An approach is suggested to generate effectiveness criteria for shipboard fighters as applies to air defense missions. This approach, among the factors influencing efficiency of air raids repulsion, takes into account such generally accepted ones as striking force losses or losses for both conflict sides. Besides one more factor is considered, which determines favorable conditions for operation oj shipborne anti-aircraft missile weapon systems. This factor estimates breaking degree for formation of the air striking force. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zherebin A. M., Zurabian N. I. An air combat model to estimate effectiveness of advanced aviation ordnance. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 8-13. An analytical model of some two-sided conflict is suggested to support solution of conceptual design optimization problems for advanced aviation ordnance. A peculiarity of the model consists in dividing of objects used by both conflict sides into two categories including target objects appointed to hit in the given operation and striking objects used to realize the operation. A distribution problem is solved for the attacked targets as applies to the situation analyzed. Parametric analysis results demonstrate us how much important is to distribute targets properly in the conflict considered. The proposed model can be used to solve many problems related to evaluation of conflict parameters influence on conflict results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Efremov A. V., Koshelenko A. V., Tyaglik M. S. Structure and algorithms development for control systems using additional controls to achieve necessary efficiency and flight safety. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 14-21. Experimental research results are discussed which allow to prove suggestions intended to simplify manual piloting for a extremely short landing and carrier landing as well. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Frolov V. N., Garanin I. V. A methodological approach to calculation of combustion chamber thrust for a detonating engine as applies to conceptual design problems. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 22-26. An engineering technique is suggested to calculate a combustion chamber thrust values for pulse-jet detonating engines. This technique allows us to reduce significantly computation costs and time needed to solve the problem. The one-dimensional classical theory is used to compute a propagation of detonation wave in the chamber. A finite-element model based on the Euler equations is used also to compute non-steady flow of combustion products as well as to calculate filling of the chamber with a fuel mixture. A demonstration example is presented for the technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Hilkevich V. Y. An influence of temperature non-uniformity for input stream on a nozzle performances. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 27-31. An evaluation of nozzle losses for a liquid fuel ramjet is carried out by means of CFD-simulation techniques. It is demonstrated that radial temperature non-uniformity for a nozzle input causes increasing of values for flow and impulse coefficients on | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kikot' N. V., Marchukov E. Y. Development and investigation of a method to analyze heat conditions for rotor-connecting roller bearings of gas-turbine engines. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 32-36. A bench is described to test rotor-connecting roller bearings intended for gas-turbine engines. An engineering analysis method is developed basing on obtained experimental data to analyze a heat mode for the bearings with various oil feed techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivkin E. I., Sirotkin I. A. Inspection techniques for a cleaning quality evaluation as applies to cooled turbine blades throughout their manufacturing and repair. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 37-40. A serious problem emerges throughout manufacturing and repair of aviation gas-turbine engines. The problem relates to a cleaning of cooling channels within turbine blades from various contamination substances. Many techniques have been developed to perform high-quality cleaning of inner cavities in machine parts. However besides of the cleaning we need examination techniques suitable for large-scale manufacturing environment. This subject is analyzed in the paper in regard to gas-turbine engine production. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ilyinskaya O. I., Khakhin V. N. Machining techniques for materials with regular anisotropy of properties. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 41-44. Investigation results are presented as applies to manufacturing problems for a machining of aircraft parts made from single-crystal materials. Quality management techniques are suggested to obtain appropriate surface layer of the manufactured parts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveyev A. V., Bobronnikov V. Т. A technique for aircraft control system design using MATLAB/Simulink software. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 53-61. A technique is presented to design control systems for unmanned aerial vehicles (UAV). The technique suggests a step-by-step automated synthesis including solving of optimization problems for controllers basing on transient performance criteria within a space of tuned parameters. An example is described to demonstrate an application of the technique for control system synthesis in regard to a gliding UAV. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krivilev A. V., Stebletsov V. G. Computer-aided technique to synthesize logical functions for mechatronic actuator module equipped with a direct current motor. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 62-68. A synthesis technique is described for control logic functions, which allows us to obtain appropriate truth table and analytical expressions for any arbitrary method of switching with key elements. The obtained results can be transferred into various simulation systems and computer-aided design systems. The technique is implemented using the Mathematica software system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khakhulin G. F., Novikov S. A., Posadsky A. I., Eskin V. I. Investigation results for observation scheduling algorithm intended for computer-aided space monitoring system aimed to movable naval objects. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 69-78. Investigation results are presented for observation scheduling algorithm intended for computer-aided space monitoring system aimed to movable naval objects. The results confirm adequacy of observation problem statement as well as efficiency of used technique and schedule generation algorithm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Terentiev M. N. A model of energy-saving wireless sensor network with synchronization of time scales. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 79-84. A problem of lifetime increasing is discussed for nodes of wireless sensor networks using autonomous non-renewable power supply with alternation of active and sleeping time segments. A mathematical model is suggested for the wireless sensor networks with energy saving and synchronization of time scales. A time scale synchronization technique is developed to allow communications between network nodes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Konovalov V. L. An ownership capital fair cost as an efficiency cornerstone for industry capital investment projects under the crisis conditions. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 85-94. Long crisis of the world economy enhances significance of scientific approach to effective management of capital structure for industrial enterprise in regard to its crisis threat resistance ensuring. An integrated model is suggested to determine the ownership capital fair cost for the enterprise taking into account such factors as world financial system conditions, state and industrial sector risks as well as risks which are inherent for the enterprise. Conclusions and recommendations are presented about relatively efficient ways to overcome revealed conflicts within the bounds of the integrated model. The obtained results are based on analysis of the conflicts which are a cornerstone of contemporary financial management and associate with ownership capital fair cost determination. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sidelnikov Y. V., Bukhalov V. А. An improvement procedure based on aircraft industry case to define development jobs for high-technology projects. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 95-100. An improvement procedure is suggested to define engineering system development job on the preliminary project stage. The procedure consists of corrections sequence basing on solution search for predefined auxiliary tasks as well as on answer search for a set of basic and explaining questions | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fomkina V. I., Kolosov I. M. Some aspects of export sale proceeds for aircraft industry enterprises. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 101-106. Origins of dynamics are revealed for a financial condition of aircraft industry enterprise in regard to production export. Two basic kinds of financial risks are exposed to manage effectively export sale proceeds of the enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ganzhela N. S., Efimov D. A., Mirzoyev E. G. Building of integrated production structures for aircraft industry enterprises basing on their reequipment. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 107-112. Some ways are suggested to build integrated production structures in the Russian aircraft industry enterprises affiliated with the Russian Technologies State Corporation. It is concluded that one of directions to enhance the competitiveness of new generation aircraft is reequipment production capabilities of the enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozhevnikov A. S., Rybackov K. A. A spectral analysis method for stochastic systems as applies to financial mathematics exemplified with the Black—Scholes model. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 113-125. We consider the Black-Scholes model, which is used to estimate stock prices and European options. The problem of finding stock price probability density function, expected stock price and its dispersion as well as the option premium is studied in the paper. To solve the analysis problem which consists in finding of probability density function for stock price we develop the algorithm based on spectral form of mathematical description. We also use the Monte-Carlo method to control an accuracy of approximate solution. The Black-Scholes formula is used to calculate the option premium. Simulated results are analyzed for different variants of the stock price and values of the option behaviors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilevsky D. V., Spirin G. G., Shlyapnikov I. P. An investigation of heat conductivity for anisotropic materials. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 126-129. The short-term measurements technique for irregular thermal conditions is applied to investigate a heat conductivity of orthotropic materials, in particular artificial asbestos named amphiboles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Salganik R. L., Mishchenko A. A., Fedotov A. A. Electro-thermo-mechanical effects in materials with cracks and rough coating under bending deflection. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 130-138. Models of electro-thermo-mechanical effects caused by a heat release due to electrical losses in a material with coating and rough boundary are analyzed. These effects occur under the electromagnetic field which changing rapidly enough and penetrate into the material rather superficially. Also a detachment phenomenon is studied for a thin layer of a material which can be the coating. The phenomenon caused with a bending instability of the layer is considered as well as the layer subsequent behavior. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Moiseev K. A. About resonant oscillations of nonlinear systems. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 139-146. A non-traditional approach is presented to find out resonant frequencies for linear and nonlinear systems. Some important results are obtained basing on this approach. The results change appreciably our ideas about dynamical behavior of nonlinear systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korovaytsev A. V., Korovaytseva E. A. Locally analytical method to calculate normalized integral matrices in mechanics of deformable solid body. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 147-152. A locally analytical method is suggested to calculate normalized integral matrices for linear models of deformable elements. The matrices are defined for boundary problem conditions expressed in vector-matrix form. Lattice function theory techniques are used to derive integral matrices in analytical form basing on some special identity transformation of the source mechanical problem. The method allows us to abandon usage of mesh functions. A typical example demonstrates capabilities of the method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Emelin N. M., Tarabrova I. N. An approach to justification of indices to evaluate research activity of young Russian scientists. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 153-156. Research activity of a young scientist as a complex and multilateral system cannot be evaluated completely using traditional techniques and indices. It occurs because of activity results present a new knowledge realizing in scientific publications, patents, know-how etc. It is needed to use a specific system of indices which allows us to evaluate research activity of young scientists with completeness and authenticity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sharonov A. V., Novosyolov S. V. An algorithm for geoinformation measuring systems to reconstruct relief fragments of underlying surfaces. Aerospace MAI Journal, 2009, vol. 16, no 4, pp. 45-52. An algorithm is suggested to generate re lief fragments for some underlying surface. This algorithm is based on a two-dimensional wavelet transform. It provides us to reconstruct required re lief fragment without information about whole underlying surface. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pirogov S. Y., Yuriev A. S., Tipayev V. V., Makhrov A. S. A numerical stream simulation for external-compression inlet with energy supply into incoming supersonic flow . Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 154-159. Numerical investigation results are presented to demonstrate an influence of energy supply on a shock-wave structure in external-compression inlet for its nominal operation mode. It is shown that energy supply into incoming undisturbed supersonic flow can be used to change shock-wave structure arising in the inlet under the nominal operation mode. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Antufiyev B. A., Smiyan A. В. Dynamics of cylindrical shell with attached cantilever plates. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 150-153. An approximate evaluation of natural frequencies is described for a lower oscillation spectrum range of a thin elastic finite-length cylindrical shell with two attached cantilever elastic plates. The plates are attached to the shell along a section of generatrix. The described problem is solved in the contact statement with satisfaction of compatibility conditions for the shell and the plates according to the Bubnov method. Some examples are considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Belousov A. I., Prisekin V. L., Rastorguyev G. I., Fedotova O. R. An influence investigation for dynamic aircraft properties in regard to stability of loading channel. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 145-149. An oscillation onset process is analyzed for a test bed intended for carrying out aircraft fatigue tests. A mathematical model is derived to describe a loading for cantilevered aircraft wing with a large aspect ratio value. It is shown that usage of a proportional control law for the loading of elastic inertial system with low damping ration leads to forced oscillations in the system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V., Tran Ngoc D. . Dynamic state of beam system with variable parameters under moveable load action . Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 138-144. An important applied problem is studied, which consists in oscillation analysis for two beams with variable parameters under moveable load action. A technique basing on decomposition on natural oscillation modes is used to derive mathematical model for the problem. The elastic beam system must be expanded in this case with zero-motion modes as for a perfectly rigid body case. Lagrange second-degree equations are used to calculate oscillations of the system. Effect of various factors to dynamic state of the beam with variable parameters is investigated under moveable load action. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kireyev V. I., Pavlov Y. A. Integro-differential parabolic splines in applied shaping problems for complex industrial products. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 130-137. One-dimensional and two-dimensional Integra-differential parabolic splines are derived to approximate shapes of structural elements for complex modem industrial products. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rubinchik E. A. Satellite monitoring data in metrics related to analysis of market for agricultural sector products. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 126-129. A role of satellite monitoring data is considered to forecast a market development for agricultural products. An implementation experience for remote sensing techniques is analyzed as applies to the Russian agricultural sector. Some achievement examples in arrangement, processing and utilization of satellite data are discussed in regard to the European Union countries practice. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Popov E. V., Muborakshoyeva D. T. A possibility analysis to achieve strategic goals of the United Aircraft Corporation in regard to the civil aircraft market. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 116-125. An analysis is carried out to provide a correct definition of strategic goals for the Russian Joint-Stock Company «United Aircraft Corporation» (UAC). Medium-range and long-range forecasts are considered in regard to manufacturing of aircraft for the civil aviation. Material resources and intangible assets are evaluated for the member companies of the UAC to reveal its major references in future market competition. A comparative study is performed to estimate management level for aircraft manufacturing enterprises from the standpoint of international regulations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Actov V. V. Industrial engineering techniques for aircraft manufacturing within the bounds of integrated production systems. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 110-115. Methods are presented to evaluate an economic-organizing stability and manageability of integrated production systems in aircraft industry. A cooperative efficiency estimation technique is suggested for these integrated production systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brekhov O. M., Naing L. A. Estimation model of indexes of performance of the computer network for execution of heterogeneous tasks. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 101-109. An analytical model is suggested to estimate performance indexes for a computer network with a limited number of computing modules intended for execution of heterogeneous tasks with dynamic change of their quantity. Some transient and steady modes oj operation are considered for the computer network. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Benevolsky S. V., Goncharenko V. I. Solving of boundary-value and optimization problems related to ballistic design basing on grid function visualizations. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 90-100. A non-standard method is suggested to solve boundary-value ballistic problems basing on usage of unified mathematical models for flight vehicle motion on powered trajectory segment as well as on a surface visualization for appropriate boundary or optimization conditions. An application is demonstrated for this method to compute maximum flight range and realizable flight time range when lunching intercontinental ballistic missiles to reach a predetermined range taking into account some limitations concerning an area of warhead reentry for fixed launch directions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pilishkin V. N. Low-order robust regulator synthesis based on solving of linear-matrix relationships. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 85-89. A regulator synthesis problem for multidimensional dynamic object is studied taking into account limitations on variables and uncontrollable disturbances. A decomposition of the system into low-order subsystems is accomplished. Internal relationships between these subsystems are replaced by limited disturbances, which are not connected with each other. For each of these subsystems their own robust regulator is synthesized. Synthesis itself is based on geometrical relations, which provide the phase limitations. These relations are transformed into a parametric linear equation regarding to the synthesized regulator matrix. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malshakov G. V. Management processes automation for higher education institution basing on CALS technologies. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 77-84. Problems are considered as applies to automation management processes in institutes of higher education basing on CALS-technologies. Modem automation tools are analyzed. Some principles are formulated to support management process automation for higher education institutions. Life-cycle models are suggested for automated subsystems as well as for integration of these subsystems into whole system. An applied STEP-based protocol is developed to provide automation of management processes. A set of synthesizer, analyzer and loader for EXPRESS-schemes are implemented using VBScript language. Some software package is obtained as a result of the study to support automation processes based on CALS-technologies. The package includes synthesizer, analyzer, loader for EXPRESS-schemes, PDM PartY PLUS component from Lotsija Softvea and iterated automation subsystems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dobychina E. M. Phase noises of frequency synthesizers. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 69-76. An analysis is carried out for phase noise characteristics of frequency synthesizers with phase locked-loops. Simulation results are presented for noise processes as well as a technique to decrease the phase noise level for the frequency synthesizer output. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ravikovich Y. A., Kiansky T. N., Amelkin A. S., Kabanov N. A. Power deformations of a bearing housing at non-stationary thermal flows. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 65-68. It is shown that thermal and mechanical elastic deformations of a bearing mounting surf ace result in a damage of the bearing. Recommendations are suggested to design bearing mount assemblies free of this defect. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidov A. S., Kashelkin V. V. An estimation of damage level and stresses in cantilever samples basing on changes in natural frequency and amplitude of oscillations. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 62-64. A technique is presented to estimate damage level and stresses for structural materials. The technique is based on the conception suggested by Yu.N. Rabotnov to describe a fracture with creep process for cantilever stainless steel samples basing on changes in natural frequency and amplitude of oscillations. The oscillation amplitudes together with overload factor values can be used to evaluate beam stresses. The technique usage is demonstrated by means of some numeral examples. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Seong-up H. . Design of afterburner for high-productive fumigation facility. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 54-61. A design problem is studied in regard to afterburner for high-productive fumigation facility. The afterburner is used to clean up contaminated air from toxic substances. Thermodynamic analysis is performed basing on the principle of chemical equilibrium for arbitrary heterogeneous system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Fedorov M. Y., Kraus E. I., Fomin V. M., Shabalin I. I. Simulation of structural impact actions to ensure safety for space nuclear power systems. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 49-53. Some approaches are considered to ensure safety for space nuclear power systems. These approaches are related to develop forecasting techniques for accident radiation consequences caused by impacts on structure of space nuclear power systems. Several interrelated problems are generated with solutions, which make it possible to reveal radiation consequences for the nature and population. Computation results are presented to describe destruction analysis problem for the nuclear reactor of space nuclear power system. The destruction is caused with a high velocity impact by space debris as well as with impact because of fall on the Earth surface. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Guskov K. V., Khartov S. A. A measuring system for working gas flow rate to support electro rocket thruster tests. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 41-48. A necessity is substantiated to replace RRG-type and similar flow meters in a typical test bench working gas supply system. The replacement is carried out for a new thermal flow meter having no analogs to support unambiguous and exact measurements for main parameters of a thruster providing its thrust efficiency and specific impulse. Descriptions of created flow meter models are presented as well as their parameters and usage recommendations with the test bench to support ground testing of electro rocket thrusters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Obukhov V. A., Pokryshkin A. I., Popov G. A., Yashina N. V. The usage of a sustainer electric propulsion system for spacecraft attitude control. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 30-40. Problem of spacecraft attitude control for a non-coplanar inter-orbital flight using hinged sustainer electric propulsion has been studied. Trajectory legs corresponding maximum angular acceleration of the spacecraft longitudinal axis at plane configuration for the solar panel (SP) orientation to the Sun are under investigation. It has been shown that small permitted deviations of the SP orientation to the Sun provide reduction of control moments and deflections of cruise propulsions. Possibility is important to change one SP orientation variant by another differing the sign of the SP rotation angle, which provides reducing control moment values. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidova N. S., Dvornikov M. V., Nesinova A. S. Membrane technology for multilayer structures of clothing with thermal control intended to extreme conditions. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 22-29. Smart clothing imitating human skin functions and animal hair coat realizes heat exchange dynamics and perspiration. It becomes therefore an active mechanism of human interaction with external environment for a range of extreme modes. An attempt is carried out to formalize biological processes of human surface heat transfer, which is exemplified for a case of three-layer design clothes with a set of parameters of porosity, permeability and moisture absorption, taking into account the phenomena of wettability and capillarity, which are inherent in the membrane technology. The layerwise mathematical model was presented, in which the parametric analysis was carried out. The results are shown in the criterial form. The main parameters that determine the mathematical model are Marangoni number, Weissenberg number, capillary number. The structural recommendations are formulated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Boldyrev A. V. Wing structural optimization under strength and stiffness constrains. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 15-21. A new method is proposed to select some reasonable wing structure layout at early design stages. The method is based on a special finite element model with consideration of constraints on equivalent stresses and generalized displacements. An appropriate computational example is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhuravlev P. V. Design of passenger airplanes taking into account operational uncertainty factors related to aircraft fleet structure. Aerospace MAI Journal, 2009, vol. 16, no 3, pp. 5-14. The article substantiates the necessity of taking into account the uncertainties during the process of design of passenger airplane as a part of an optimal (reasonable) fleet. Main uncertainties are sorted into groups. After that the uncertainties with most influence on the design are selected. The appropriate methods for taking the chosen uncertainties into consideration are proposed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakulin V. N., Martynenko S. I. A robust multigrid technique to solve continuum mechanics problems. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 171-175. A problem statement is suggested to solve a broad class of application problems. The problem associates with computing technology development providing advanced black-box type software generation to solve continuum mechanics problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churkina T. E. On stability of a satellite motion in elliptical orbit in case of cylindrical precession. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 162-170. Stability is analyzed for an angular satellite motion in elliptical orbit in case of cylindrical precession. The satellite comes in this case to its initial position revolving on its axis of symmetry within the time of one revolution in the orbit in absolute space. A first approximation of stability regions is obtained in the space of problem parameters including inertial parameter and orbit eccentricity. A detailed nonlinear motion stability analysis is carried out for these regions considering cases with and without 4th order resonances. The stability is inspected for a majority of initial conditions in terms ofLebesgue measure. Regions of parameters values are obtained to satisfy formal stability conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ganiev O. R. Resonance effects under wave propagation in porous medium saturated with liquid. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 154-161. A one-dimensional problem is discussed related to a resonance effects as applies to some finite layer of porous liquid-saturated media. It is shown a possibility to generate unidirectional movements of liquid in porous media with such kind of the wave effects. Resonance nature of these processes is investigated and the main role of a fast wave associated with momentum transfer in a skeleton is determined. The wave influence on such media leads to huge average effective pressure gradients.. Important factor in simulation of wave processes is a friction in the skeleton, because it causes qualitative changes in process characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shustov S. A. A numerical simulation of termogas dynamic processes in low thrust engines at non-ideal conditions. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 146-153. A physical problem statement is discussed as applies to simulation oftermogas dynamic processes in low thrust liquid-propellant rocket engines at non-ideal conditions. The statement is based on experimental results obtained by the author of the paper. Appropriate mathematical model is discussed as well as a numerical algorithm and its software implementation to solve the model. Validation results are presented to show adequacy of the model. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Starostin K. I. Mathematical modeling of aircraft environmental control systems with air humidity account. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 141-145. A mathematical model is presented for a high-pressure water separation scheme. The scheme is included as a part into aircraft environmental control systems. Numerical techniques are described to solve the model equations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ananyev A. V., Borisov D. M., Vasiutichev A. S., Gidaspov V. Y., Degtyaryov S. A., Laptev I. V., Rudenko A. M. A numerical simulation of three-dimensional two-phase flows with chemical reactions for ramjets. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 131-140. A numerical technique is described to simulate viscous flows with chemical reactions as applies to flowing ducts of air-breathing jet engines. Submodels and computation techniques are suggested for flows in air intake, ducts and combustion chambers of the engine. Test results are presented and compared with experimental data as well as with numerical simulation results for three-dimensional flow examples. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinnikov V. V., Ganiev K. O., Reviznikov D. L., Ukrainsky L. E. A dipole method for simulation of stirring processes. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 122-130. Some mathematical modeling aspects are discussed in regard to stirring processes. A dipole method is suggested to simulate stirring in fluids as well as to evaluate quality of resulting mixture. It is shown that dipole method is a compromise between high-precision, but resource-wasted contour method and economical, but less accurate marker method. Benefits of the method are versatility and applicability for enclosed and open flow ducts. Besides the method is generalized rather easy for three-dimensional case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kudryavtseva I. A., Panteleyev A. V. A modeling of two-component plasma dynamics with charged particles collisions near a flat probe. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 114-121. A mathematical model is suggested to describe collision behavior for two-component plasma and charged particles nearby a flat probe. A technique is presented to solve this problem. The technique is based on composition of the Particle-In-Cell Method and the finite-difference method (the splitting method). Results obtained illustrate some influence of charged particles collision on the plasma characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vasilevsky D. V., Preobrazhensky B. A., Spirin G. G. Thermal activity for disperse material with a melting component. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 109-113. A measurement technique for thermal activity at irregular heat conditions is used to study disperse materials with melting filling components. It is found that melting measurement results indicate efficient thermal activity depending on melting heat. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kryukov I. A. A computation of turbulent supersonic flows. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 101-108. Some modifications of the k-ε turbulence model are considered as applies to numerical simulation of supersonic turbulent flows. Strong compressibility and occurrence of regions with large parameter gradients (i.e. with dynamical gas medium discontinuities) are typical for these flows. An equation for turbulent kinetic energy in compressible case contains normally three new terms. These terms discussed briefly in the paper are compressible dissipation, pressure-dilatation and turbulent mass flow. Existence of discontinuities leads to considerable increasing of turbulent kinetic energy production due to gradients of mean velocity. It results in significant deviation from equilibrium state near discontinuities. It is for this reason that some non-equilibrium modifications of the k-ε turbulence model are suggested in the article. All considered modifications are analyzed basing onflow calculation results in regard to a supersonic under-expanded jet with complex shock wave structure and flow as well as in regard to a supersonic nozzle with separation. A new version of the k-ε turbulent model is suggested to contain considered modifications. This version is able to calculate both flow classes with a good accuracy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y., Losev S. A., Severina N. S., Yarygina V. N. Influence of electronic excitation on a shock wave structure in oxygen. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 93-100. An influence of electronic excitation on a shock wave structure in oxygen is estimated. Electron-excited molecules participating in chemical reactions behind the shock wave are considered as separate components of a mixture both in their basic and singlet conditions. A mathematical model of the process is suggested as well as a composition is revealed for considered components, electron-chemical reactions and accepted values for speed constants of the reactions. Gas parameters behind the front of the stationary shock wave are simulated. Estimation results are presented to demonstrate an influence of electronic excitation on the parameter distribution for the flow behind the stationary shock wave. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shustov S. A. Experimental investigation of cross profile generation processes for thermogas dynamic parameters of combustion products in nozzle inlet for regular liquid-fuel microthrusters. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 85-92. An experimental research technique is suggested to investigate cross profile generation processes for thermogas dynamic parameters of combustion products in liquid-fuel microthrusters. The technique is based on a modular structure for microthrusters with self-inflammable propellants. The structure consists of regular agitating head and replaceable insertions to investigate flows of the combustion products from agitating head up to nozzle inlet of the microthruster. Experimental results are presented to demonstrate efficiency oj the technique to reveal basic relationships for generation processes in regard to thermogas dynamic parameters of combustion products in liquid-fuel microthrusters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abgarian V. K., Abgarian K. К., Ryzhov Y. A. A numerical simulation of surface relief changing for polycrystals under ion-plasma flow irradiation. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 79-84. A numerical simulation is discussed as applies to surface relief changing for polycrystals under ion-plasma flow irradiation. A mathematical model is suggested basing on a transition to curvilinear spherical geometry to generate needed computational scheme. The purpose of the transition consists in computational area closure on itself. This approach allows us to eliminate determination problem for boundary conditions. The proposed «closure of boundaries» technique could be applied for arbitrary N-dimensional computational area. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Markina N. L., Reviznikov D. L., Cherkasov S. G. Mathematical model of conjugate heat-mass transfer between a gas-vapor bubble and surrounding fluid. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 71-78. A numerical simulation approach is discussed in regard to cavitational processes. A mathematical model is suggested to describe unsteady conjugate heat-mass transfer between a vapor-gas bubble and surrounding fluid. The model takes into account a spatial inhomogeneity of gas and fluid temperature fields as well as inhomogeneity of component concentration in the bubble. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov I. E. Numerical simulation of multiphase flows with large volume fraction of dispersed phase. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 62-70. A mathematical model is suggested to investigate flows of two-phase liquids for cases when a volume fraction of the first phase cannot be neglected in comparison with the volume fraction of the second phase named as the carrying phase. Both phases are described as a compressible media. A hyperbolic-type system of equations expresses conservation laws for mass, momentum and energy. A higher-order Godunov-type numerical method is developed to solve this system of equations. Computational experiment results are presented for two-phase and two-fluids cases. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y., Moskalenko O. A., Pirumov U. G. Numerical simulation of stationary detonation waves in gas and gas-droplet reacting mixtures. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 51-61. Numerical simulation results are presented for stationary detonation waves in gas and gas-droplet reacting mixtures. Cases oj existence for detonation wave minimum speed are considered as applies to hydrogen-oxygen gas mixture diluted with argon with addition of water drops as well as in methanol-air gas-droplet combustible mixture. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Romanova T. N., Anisimov A. V. A practical solution of some NP-hard software configuration problem. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 43-50. A mathematical statement of structural synthesis problem is presented as applies to software engineering field. Two versions oj the problem are discussed relating to various complexity classes as well as techniques needed to solve appropriate problems. A comparative analysis is carried out for the considered problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Anisimov A. V., Romanova T. N. Theory and practice of NP-hard structure synthesis problem solution by means of software tools. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 34-42. An example of NP-hard structure synthesis problem solution is described. The problem is typical for enterprise automation processes. Optimization statement of the problem is formulated. Appropriate software implementation is presented in regard to such problem class for three approximate solution search methods as well as for one accurate development search method. Data structures used for the method implementation are described. Analytical and numerical estimations are compared for precision and complexity oj involved optimization techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sologub G. В. A development of simulation test system. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 28-33. A structure, functionality and features are described for a software tool set meant for generation of tests. A scheme of sequential question generation is presented as well as a technique to evaluate testing results. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mashkov K. V. A transport level integration for applications using open source technology. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 19-27. Many medium-size and large corporations use a variety of computer applications for managing data, including supply chain management applications (for managing inventory and shipping), customer relationship management applications (for managing current and potential customers), business intelligence applications (for managing internal operations), and other types of applications (for managing data such as human resources data, internal communications, etc). Unfortunately, such applications typically cannot communicate with one another in order to share data or business rules; for this reason, such applications are sometimes referred to as islands of automation or information silos. This lack of communication leads to inefficiency, in the form of the same data having to be stored in multiple locations, or straightforward processes that are unable to be automated. This article reviews two integration platform namely Mule ESB and Jboss ESB. A bank credit reception is considered as an example. Architecture of systems and appropriate integration decision is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybalko A. A. Virtualization as a basis of next generation computer security systems. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 12-18. Application aspects are discussed in regard to virtualization mechanisms intended to protect servers and workstations. A comparative analysis is carried out for virtualization tools available on the market at the present time taking into account fault tolerance aspects for system and application programs. Protection techniques are proposed basing on virtualization andparavirtualization mechanisms. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panteleyev A. V., Letova T. А., Kondakov V. K. Computer-aided textbook as a tool to guide a student self-instruction activity in regard to study of mathematical disciplines. Aerospace MAI Journal, 2009, vol. 16, no 2, pp. 5-11. A technology for development of computer-aided textbooks is proposed to support education in mathematics. The technology is based on representation of education activity as some information process with closed-loop feedback. The proposed technology is applied in the Mathematical Cybernetics Department at the MAI to generate information bases for computer-aided textbooks used to guide self-instruction activity of students. The computer-aided textbook technology could be used also for distance education tasks by means of relevant information bases placed in the Internet. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitin N. B., Makhrov V. P. Aerohydrodynamic characteristics estimation for a grid fin by means of numerical solving of Reynolds-averaged Navier-Stokes equations. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 136-140. A technique is suggested to estimate aerodynamic characteristics for a grid fin by means of numerical solving of Reynolds-averaged Navier-Stokes equations. An effectiveness of the technique is evaluated as applies to design problems for thr grid fin as well as to prelimitary estimation for lifting properties of this fin. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shtyrlin A. F. Specific particle charge nouniformity and kinetic losses in a colloidal electrojet thruster. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 129-135. The time-of-flight measurement technique for beam parameters is studied to estimate polydispersity of sputtering for liquid working media in a colloidal electrojet thruster. The investigation is carried out using a module of the thruster equipped with 18 emission units. These 18 units generate in total the beam with 75 mm diameter on the outlet of the module. A kinetic efficiency value for the module varies in the 0.55..0.75 range depending on fluid flow rate and particle outlet velocity values. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zinchenko A. S., Yudina O. V. A financial planning method for production activity of aircraft industry enterprises. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 124-128. A method is suggested to budget a production activity of aircraft industry enterprises. The method is aimed to enhance efficiency of the enterprise activity. Appropriate contents and operational procedure are presented to obtain a consolidated short-term budget for the aircfaft industry enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishin V. M., Phyo M. K. Optimization of non-failure operation of one class components of aircraft control systems at the active loaded reservation. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 116-123. Reliability enchancement is one of the important problems, which aircraft control system designers are needed to solve. An approximate analytical technique and a numerical one are suggested to optimize some class of aircraft control system units basing on active redundancy approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Azimov D. M., Gorbatenko S. A. About optimization of nominal trajectories for synthesis of onboard spacecraft guidance algorithms. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 107-115. An analytical approach is considered to solve a variational trajectory optimization problem for spacecraft center of mass in the Newtonian field. Classes of extremal and optimal thrust arcs, which are classifield depending on values of power and specific impulse are defined using the Clebsch condition. Two classes of analytical solutions are obtained for extremal spacecraft motion with a limited power. The thrust arc solutions obtained can be used in spacecraft maneuvers design for transfer into some specified orbit or for escape from some elliptical orbit. The analytical definition technique to find extremal solutions of the variational problem can be used as a tool to obtain reference trajectories needed to solve spacecraft guidance problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nevolin A. O. New methods for improving open prorocols information systems security. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 101-106. Open XML-based protocols are described with their application areas as well as their intrinsic virtues and shortcomings. Existing techniques are analyzed to support information security when these protocols are used. Disadvantages are revealed for these techniques. New approach is suggested to enchance security of transferred data basing on the protocols and ita theiretical efficiency is evaluated. Test results are presented to demonstrate efficiency of the approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sharonov A. V., Novosyolov S. V. An algorithm for generation of undrelying surface relief by means of geoinformation measuring system. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 95-100. A new technique is proposed to generate underlying surface relief basing on measurement of height results for this surface in a finite number of points. The technique is based on 2D wavelet transform. It allows us to represent the relief with suitable accuracy and prevents necessity to save all information about underlying surface relief. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Beschastnykh V. N., Ravikovich Y. A., Sokolov A. N. Evaluation of static bearing strength for a tilting-pad hydrostatic gas bearing. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 84-94. There is an application area for turbomachines where using of gas-lubricated bearings is economically resonable in regard to rather heavy rotors. It is referring to turbogenerators with 500..2000 kW capacity value equipped with high-freguency electrogenerators. Mathematical modelling results are presented in the paper for gas flows within lubrication layer of tilting-pad hydrostatic gas bearings. Experimental data are described to demonstrate bearing strength and rigidity for discussed bearings. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Akhmetova E. R., Tazetdinov R. G. A modification of titanium alloys for friction pairs by periodic discharge in liquid flow. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 73-83. An analysis of metal is carried out for friction pairs basing on biological compatibility criteria. An influence of periodical discharges in liquid flow is analyzed for the materials as well as an effect of these discharges on tribomechanical characteristics of titanium alloys. Besides the previous results are generalized. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobey V. V., Evstratov S. V. New trends in technology for winding of composite material construction. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 61-72. Major trends are discussed in winding technologies in regard to thread constructions made of composite materials. Some data are provided about design features of various automated equipment as well as storage, impregnation and preparation devices for threads, cords, belts and their combinations. A value selection for basic winding parameters of layer-built constructions is carried out using algorithms based on concepts of geometric net and line on the surface. Main features are revealed for an algorithm intended to develop executive devices of a winding machine. Some examples are presented for programs to supportwinding of various constructions shaped as a body of revolution. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sorokin V. A., Zakharov N. N., Sharov M. S., Yanovsky L. S. Experimental investigations of mixing process in a combustion chamber model for combined propulsion system with asymmetric air intake. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 54-60. The technique of measurement carbon dioxide concentrations — simulator of gas generator products in combined propulsion system, in an airflow of the model of combustor is described. The results of experimental investigations of mixing process in model of the combustor are shown. A measurement technique is suggested to evaluate carbon dioxide concentrations in combustion chamber gas flow produced by a simulator of gas generator products in combined propulsion system. Experimental results are presented for mixing processes in a model of combustion chamber. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenov P. N., Shkarban I. I. A surface temperature influence on sputtering characteristics for boron nitride based ceramics. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 49-53. Experimental results are presented to study influence of surface temperature on values of sputtering yield for boron nitride based ceramics with surfaces irradiated by 300 eV Xe+ ion flows. The surface temperature varies in this case in the 300-1100°C. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molchanov A. M. A calculation of supersonic non-isobaric jets with compressibility corrections in a turbulence model. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 38-48. A turbulence model is suggested to consider effect of high-speed compressibility on the turbulence process. Some series of numerical computations for turbulent non-isobaric jets have been carried out with different flow models. A satisfactory compliance is achieved between obtained numerical results and experimental data. A comparison of the simulation results with these experimental data reveals how important is to take into account an influence of compressibility corrections on the intensity of turbulent mixing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Hilkevich V. Y. Numerical operability evaluation for an ajustable two-position nozzle. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 31-37. A mathematical model is suggested for adjustable two-position nozzles intended to liquid fuel ramjets. An example is solved to demonstrate operability of the nozzle both in closed and open positions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A., Onishchik I. I., Yun A. A. A simulation of mass and heat exchange within model combustion chambers. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 27-30. Some results are presented to demonstrate application of the Fastest-3D package for simulation of turbulent processes with heat and mass transfer in model combustion chambers. A comparison of numerical and experimental data is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bordakov V. N. Working process theory and computation for pneumohydraulic systems. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 15-26. A system of differential equations is derived basing on relationships for mass, energy and impulse balances to describe time changes of pressure and temperature derivatives for gaseous working substance in regard to various types of pneumatic systems. Numerical simulation of pneumohydraulic systems demonstrates a close fit between results obtained by mefns of suggested mathematical model and experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kudriavtseva N. S., Malozemov V. V. Joint optimization of mass and power characteristics for spacecraft thermal control system and cooled instruments under specified reliability requirements Propulsion and Power Plants. Aerospace MAI Journal, 2009, vol. 16, no 1, pp. 5-14. The article is related to joint optimization problems for mass, power and reliability characteristics of thermal control systems and cooled radio electronic equipment for long-term mission spacecraft with high reliability requirements. As equipment operational reliability depends maintly on cooling medium temperature it is interesting to choose some optimum temperature level at minimum mass and power characteristics under condition of required reliability. The suggested technique allows us to shoose optimum equipment redundancy level as well as optimum temperature level for thermal control systems at minimum values of mass and power characteristics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dmitriev O. N., Ekshimbayev S. K. Basic conceptual aspects of management system re-engineering for a modern Russian defense industrial enterprise. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 7-10. Problem aspects are discussed to reorganize in-house management system for a modern Russian defense industry enterprise. The reorganization is a transformation of mainly empirical management activity with insufficient quality level into highly efficient managerial actions basing on technical and economic assessments of management decisions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sidelnikov Y. V., Bukhalov V. А. Project selection procedure based on multicriterion model. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 11-17. A procedure is suggested to select scientific and engineering projects using multicriterion model of decision making for a problem situation. The procedure is developed by the authors of the paper. The decision is made by some group of experts basing on analysis of specially structured information about project features. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ageyeva N. G., Biriukov A. S. An organizational positioning management mechanism for industrial enterprises: new ways to form conceptions of positioning and effectiveness management. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 18-21. The article is concerned with positioning management and activity effectiveness for industrial enterprises in the conditions of complicating environment. Some aspects and causes are discussed for business competition on industrial markets. A necessity is substantiated to change a plant management. A management improvement problem is formulated to generate integrated model of positioning management for industrial enterprises. The model core is management of positioning strategy and activity effectiveness for industrial enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolmykov V. A. Convergence urgency for manufacturing and marketing management of enterprise belongs to the modern Russian high-tech industry. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 22-26. A conceptual innovation is suggested which consists in management convergence and integration for enterprise production and marketing activity in regard to the modern Russian high-tech industry. Preconditions and problem aspects are discussed to realize appropriate support research. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kochetkov V. I. Features of resource effective management technologies (lean-technologies). Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 31-38. Basic management principles are given for modern institutions. An expansion of successful application area is discussed for these principles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mikheyeva L. S., Komarova N. V. A build-up of enterprise development strategy on the basis of correlation for operational and cost estimation management models. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 27-30. A mechanism is presented in the article to manage an enterprise basing on system decisions and development strategy. The mechanism uses operational and cost models. This approach allows to reach efficiency for business processes and to ensure appropriate activity supervision for the enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Erygina L. V. Principles and tools of strategic planning for innovation activity of industry enterprises. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 39-44. An integration of defense industry enterprises into the market economy as well as necessity to enhance their innovation activity are conditions providing a stable progress of the defense industry within the bounds of military-technical co-operation and conversion of production. A high uncertainty level and variability of external and internal environment factors caused by the modern defense industry progress tendencies lead to necessity of further development and application for tools and techniques of strategic planning. The tools and techniques have to be put to use in planning practice in regard to innovation activity in defense industry enterprises. An innovation strategy becomes an important factor, which allows to enhance competitiveness and to preserve production in innovation potential of the defense industry enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galkina E. E., Malko E. V. An open accounting submission as a part of competitive conception of strategic marketing. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 45-49. Social responsibility is now for a business one of the most important aspects. An enterprise image becomes strategic fictitious asset. An open accounting submission exerts a positive influence on the enterprise image. The open accounting makes a possibility for the enterprise to demonstrate its social responsibility and goodwill to follow principles of stable progress as well as to display activity results in economic, ecological and social areas | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kukushkin A. V. Development of a project management system model on the basis of automatic control theory. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 50-54. Conceptual and mathematical models of project management system are suggested in the article. These models are based on approach successfully applied in automatic control theory and system analysis. A significance of the model elements is discussed with regard to project management. A definition for the model is formulated according to system classification in automatic control theory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grigorash K. V. A price stimulation of development for defense industry enterprise within the bounds of state defense order. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 55-60. Potential development aspects are discussed for a Russian defense industry enterprise. An influence of state defense order is shown as applies to the condition of the enterprise. A scheme is synthesize for an operation of the system implementing the state defense order. A classification is presented for indirect performance measures, which evaluate effectiveness of spend the state defense order funds. An organizational and economic mechanism is built basing on the indirect performance measures providing price stimulation for development of defense industry enterprise potential within the bounds of the state defense order. The results presented in the article demonstrate a suitability of the approach to the price stimulation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pimenov A. N., Panagushin V. P., Semenov P. N. An analysis of unprofitability influence on enterprise net wealth value. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 61-64. One of the key indicators of financial stability and appeal for an enterprise is its net wealth. The net wealth demonstrates the real owned capital of the enterprise. A drop of the net wealth relate as a rule to losses caused with financial and economic activity of the enterprise. Joint-stock companies with net wealth less than their authorized capital stock are at the present time attractive objects for company takeover. Joint-stock companies with understated net wealth have as a rule low market equity value. This circumstance produces favorable conditions to buying up stock of the company for the purpose of management encroachment as applies to the company. A technique is presented to analyze an actual value of net wealth basing on accounting calculations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gusarova Y. V., Klonitskaya A. Y. A relationship analysis for creditworthiness and unprofitableness for industrial enterprises. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 65-69. An original technique is suggested to diagnose unprofitability causes for industrial enterprises. Main research goal is detection of «fictitious» unprofitability indicators for the enterprises basing on interconnections between their indexes of tax loading and paying capacity. The unprofitability causes are described as well as their indicators in external accounting statements. Influence measures are suggested to prevent «improper» business. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chaika N. K., Zverev A. M., Chistov P. V. An enterprise economical management technique based on diagnostics and unprofitability analysis. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 70-74. A substantiation is suggested in the article for such economic category as unprofitability. An original technique for enterprise economic management is presented basing on diagnostics and analysis of unprofitability. The technique uses indexes from three groups. These groups are: indexes defining effectiveness of managerial and commercial expenses as well as financial and other kinds of activity; indexes defining effectiveness of investment projects for the enterprise; indexes defining effectiveness of expenses related to profitable enterprise objects. Most significant causes are revealed basing on the indexes for the enterprise unprofitability. Measures are developed to improve financial and economic mechanisms of the enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Agapov S. A., Kulikova A. N., Khomutova Y. V. Simulation of company value basing on a set of balanced indexes. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 75-79. One of important aspects of company value management is discussed in the article. The aspect consists in planning of company value change within a budgeting system basing on a set of balanced indexes, which influence the company value. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zerkina E. N. Conceptual aspects of indebtedness management for a modern Russian defense industry enterprise. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 80-83. Suitability is evaluated to realize management for a modern Russian defense industry enterprise in regard to its indebtednesses. This realization is based on conceptual scheme of technical and economic assessment for core management decisions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybnikov A. I., Ryzhko A. L. A development conception for information model of a high-tech enterprise. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 84-86. A methodological approach description contains in the article associated with formulation of modeling concept for aerospace industry enterprise. This approach is directed to development of integrated information management system basing on the enterprise model. Initial theoretical statements of the concept are presented as well as its configuration, model levels and modeling aspects taking into account. The concept is formulated basing on long-term practical experience in development of information management systems for Russian aerospace industry enterprises. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dzhamay E. V., Kalachanov V. V. An economic selection mechanism for corporate information systems with regard to organization of aircraft production. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 87-91. An economic mechanism is discussed in the article to automate effectively production processes in aircraft industry enterprises. A system of indexes is suggested to select basing on their values some corporate information system. An expert judgement based procedure is demonstrated to evaluate values of the indexes by applying information management techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kobko L. I. Models and techniques of integrated logistics management for aircraft production organization. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 92-99. A theoretical scheme is presented for integrated logistics management in regard to aircraft production. Besides a methodological approach is formalized as well as some review is carried out for appropriate algorithms, models and tools. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baskov A. O., Degtiariov A. V., Oghanov V. A. Application of activity-based approach for operation planning with respect to information technology divisions of aircraft industry enterprises. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 100-103. A problem of preservation and development takes on special significance last time in the Russia as applies to scientific and production potential of aircraft engineering complex as well as a problem of enhancement for its competitive ability. It is necessary that considerable attention have to be focused on development of high technologies as well as on integration transformations in aircraft production area. Such transformations presume more intensive application of information technologies. Some aspects are discussed in the article as applies to management efficiency enhancement for information technologies by means of activity-based planning techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sirotinsky V. V., Semenov D. V. Techniques for data quality enhancing during development of corporate data warehouse. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 104-108. Data cleaning aspects are discussed in the article as applies to data entering into some data warehouse from various sources. Principles are described to extract, transform and load data into warehouse as well as optimization techniques to reveal and correct «polluted» data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kostina G. P., Kolesova E. A. An improvement of model and information support to select component suppliers for projects implemented in the Sukhoi Design Bureau. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 109-113. Problems related to procurement system are discussed in the article as applies to aircraft industry enterprise. A model is suggested to select suppliers. Recommendations are devised to embed the model into integrated ERP system for the enterprise. The recommendations allow us to enhance a labor productivity of the logistics staff as well as to reveal reserves for economy of the enterprise funds. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nizhegorodtsev R. M., Petukhov N. A. Trend factor models for forecasting of gross regional product (for regions of the Central Federal District as an example). Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 114-120. Trend regression models to forecast a gross regional product (GRP) are developed and applied in the article. The models allow us to take into account such factors as capital, labor, information expressed in their quantified form. The models allow us also to evaluate a contribution of information production into economic growth. Results obtained by means of the trend regression models are capable to serve as a reliable basis for clusterization of the Russian regions. The models have been tested for regions of the Central Federal District as an example. The relative error for the GRP forecast does not exceed 10% as a rule. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Novikov A. N. A process development for integration of enterprise financing management with its strategic plans. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 121-128. A structure for integration of enterprise financing management with its strategic plans is suggested as applies to support financial responsibility of the enterprise. Procedures and techniques are developed which allow us to make financial planning for the enterprise accordingly to its strategic goals. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Tarasova E. V., Fomkina V. I. Some aspects associating with cost of capital . Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 129-132. Main components are revealed for a capital of companies. Factors are detected influencing price of the capital. Numerical models are generalized for the average weighted cost of the capital. Conditions are detected for effective activity of a firm as applies to management of return on equity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kalakutina E. Y. Features of credit process organization in commercial banks. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 133-136. Organizational aspects of credit operations are studied as applies to the Russian Federation commercial banks. Main stages are structured for the crediting process. Specific features are revealed in regard to implementation of each process stage. Basic critical factors are detected as well as parameters influencing considerably on a quality of business processes for each stage. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Melnikova G. V., Moshchelkova V. Y. A development of communication policy as a basis for market promotion of high-tech industrial equipment. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 137-142. An application problem is discussed related to usage of marketing tools in management of production and sales activity for high technology enterprises. An approach is suggested to plan and realize a process of marketing stimulation for promotion of high-tech industrial equipment considering specific activity character for manufacturers from appropriate industry sector. A practical significance is demonstrated for suggested principles using a project related to the market promotion of autoclave equipment intended for food industry as an example. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mineyev N. A. A system for efficient support of small-scale business in the Russian Federation. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 143-146. A mechanism is presented to optimize a state regulation process related to business activity in the conditions of transition termination to market economy. Main goal of the proposed measures consist in decreasing of the regulations as well as in providing their clarity and effectiveness. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A development of educational program basing on a model of competence. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 147-155. New approaches are discussed in the article to formulate third generation state educational standards. These standards are based on a model of competence for appropriate specialist. A way from the model of competence to content of educational subject is demonstrated for one of educational discipline as an example. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Aseykina N. S. A development of management technique for prevention of occupational traumatism and morbidity in industrial plant departments. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 156-160. A conception is developed to enhance effectiveness of precautions management for occupational traumatism and morbidity. A structure of goals is formulated to reach the main goal, which consists in prevention of occupational traumatism and morbidity. Special attention has been paid to aspects associated with interest and diligence enhancement as well as with personal responsibility for department stuff related to preventive activity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vostrikova S. M. A development of hierarchical indicator system for safety of galvanic production. Aerospace MAI Journal, 2008, vol. 15, no 6, pp. 161-168. A hierarchical indicator system for safety of galvanic production is presented in the article. The system allows us to develop economic mechanism taking into account ecological, economic, technological and social aspects of the galvanic production influencing on the biosphere. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baranov V. N., Li B. K. Optimal control of light airplane during flight tests. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 62-66. A problem of non-iteration synthesis is solved in the paper to generate a control algorithm for a light airplane to go through flight tests. It is proved that the algorithm suggested in the paper is practically the same as optimal control algorithm basing on Pontryagins maximum principle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Cherepanov V. V. Identification of physical properties for highly porous fibrous material by means of statistical modeling techniques. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 109-117. A statistical mathematical model is developed for highly porous fibrous composite material. It is shown that the model allows to compute such effective parameters of the material as conductive and radiation thermal conductivity, energy accommodation coefficient, complex index of refraction, scattering indicatrix, coefficients of dissipation and absorption for radiation etc. These material features are very resource-intensive to obtain appropriate data experimentally because of their values are defined through processes with essentially local and spectral nature. These values are extracted basing on the proposed approach both from direct simulation results and from solution of inverse problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Belitsyn I. V., Kotyrlo T. V., Spirin G. G. An estimation of influence zone for electric field generated with overhead power transmission line. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 136-144. A technique is suggested to estimate an influence zone for electric field generated with high-voltage power transmission lines. This influence zone is interpreted as acting value of electric field strength generated with the power line along the major semiaxis of polarization ellipse. The zone is computed taking into account conductor and suspension strand sagging, ground effect, three-dimensional structure of a metal power transmission tower. A possibility is demonstrated to apply the technique for some real-life examples. Influence zones are calculated for these examples as applies to overhead power transmission lines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinepres A. L. Flight simulator evaluation of piloting process for a single-rotor helicopter with fly-be-wire backup control system using side control levers. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 21-26. Flight simulator evaluation results are presented to analyze activity algorithms and psychophysiologic features for a pilot interacting with some backup fly-by-wire control system for various flight modes. In addition a comparison is carried out for side control levers and conventional control sticks to assess their performance quality in regard to flight tasks and psychological loading of the pilot. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abgarian V. K., Ryzhov Y. A. A predictive model of erosion calculation for ion-plasma sources and discharge chamber channel walls in stationary plasma engine. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 40-43. A model is suggested to compute wall shape changes for discharge chamber channel of a stationary plasma engine. Computed erosion shapes were obtained for the M-100 engine. They correspond satisfactorily to data of full-scale durability tests. An appropriate computer program is able to analyze flows of atomized channel material both inside and outside of the channel. Calculation results show a film sputtering into anode region and these data are confirmed with experiments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinnikov V. V., Reviznikov D. L., Sposobin A. V. An estimation of influence zone for electric field generated with overhead power transmission line. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 101-108. A numerical simulation is discussed for thermo-erosion body destruction in supersonic flow with impurity of particles in it. An integrated mathematical model is presented including a two-phase flow in shock layer model as well as a heat-and-mass transfer model for ablative heat-resistant coating. The model of two-phase shock layer is build basing on a combination of Euler description for a gas phase and Lagrangian description for a disperse phase. A full-scale version of discrete-element method is used basing on direct numerical simulation of the impurity dynamics. Computational results are described for numerical simulation of thermo-erosion destruction for a circular cylinder. These data take into account an influence of shape changes for the streamlined body caused by mass losses on characteristics of the two-phase shock layer. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gidaspov V. Y., Pirumov U. G., Severina N. S. Mathematical modeling of quasi-one-dimensional non-steady flows of reacting gas with arbitrary number of interacting discontinuities. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 83-94. Computational algorithms are described to model quasi-one-dimensional non-steady flows for multicomponent reacting gas. Main feature of the technique suggested in the paper is a way to calculate trajectories of strong and weak discontinuities. The trajectories are moving computed nodes and their parameters are calculated by means of some dedicated algorithm. A software package is developed to solve problems of dynamics for reacting gas. Problems of such nature are important for applications as well as for educational purposes within the bounds of physical gas dynamics course of lectures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golovanov A. I., Mitriaykin V. I., Shuvalov V. A. An investigation of stess-strain state for hingeless torsion bar of helicopter rotor in geometrically nonlinear statement. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 118-127. A definition of the problem is suggested to analyze a stress-strain state for multilayer torsion bar of helicopter main rotor in geometrically nonlinear statement basing on finite-element method. A description of basic multilayer finite element is given as well as a design model for torsion bar of the helicopter rotor. The stress-strain state is calculated for appropriate operational loads. Numerical results obtained by means of the model are compared with experimental data and they correlate satisfactorily one with other. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krylov B. A., Onishchik I. I., Yun A. A. A calculation of temperature fields for a model of mixing combustion chamber. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 53-57. Results of three-dimensional simulation are presented for flows in a combustion chamber. The results are obtained by using of explicit algebraic model of Reynolds tensions. A comparison is carried out for the computed results and appropriate experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abashev O. V., Kuprikov M. Y. An application of artificial neural networks in aircraft design. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 27-33. A reduction of airframe mass is one of important aircraft design tasks. It is needed to apply modern weight calculation techniques to solve these tasks appropriately. Some approach based on artificial neural networks is suggested to compute assembly masses for transport airplanes. Mass computation for aircraft wing is described as an example. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Malyshev V. V., Li W. ., Baranov V. N. A technique of correlation analysis for characteristics of instrumentation used to support flight tests of light airplanes. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 67-75. One of actual contemporary scientific and engineering problems is design of light airplanes intended for monitoring of natural and technogeneous disasters. Flight test is very important step in design process for any aircraft including light one. Aerodynamical and other characteristics are revealed and refined by means of flight tests. This activity is based on data obtained from various measuring devices including airplane on-board ones. It is needed some preliminary analysis of precision for the measuring equipment to provide exact and valid experimental data. Results of the analysis allow us to build some appropriate equipment set needed to support flight tests. A technique is suggested to carry out a correlation analysis for characteristics of measuring devices solving the problem stated in the paper. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Avrashkov V. N., Metelkina E. S., Meshcheriakov D. V. Flame air heater for wide-range scramjet combustor research. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 44-52. A design of three-stage heater is proposed and realized to generate high-enthalpy model flow at a ground-based test-bench for combustion chambers of dual-mode scramjet research in conditions of connected-pipe test facility. A number of experiments are carried out to measure stagnation temperature fields at outlet from supersonic nozzles mounted on the heater. Test results obtained in the experiments demonstrate that the three-stage heater design is able to simulate effectively flight conditions for Mach number range M=2 ÷ 7,5 and for altitude values range H=0 ÷ 38 km. A numerical model of the heater is described basing on thermodynamic calculations. The model is intended to identify characteristics of model flow generated with the heater as well as to diagnose operating conditions of the heater. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nikitin P. V., Stepanenko S. A. A technique for assessment of blackness level for heat resistant coatibgs. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 58-61. A new technique is suggested in the paper to assess blackness level for heat resistant coatings. The technique is validated experimentally. Test results are compared with data obtained by means of other techniques and correlate with them satisfactorily. Special features of the technique are its portability, high precision and adequacy of obtained results. An algorithm of the experiment execution is described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ovchinnikov S. Y. Operation features of double-chamber shock-stuts with two kinds of structure. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 7-20. The subject of the paper is calculated analysis of double-chamber shock-struts. Introductory part of the paper contains characterization of main operation modes for shock absorption including landing shock and cross over of runway irregularities. Some double-chamber shock-struts are sel ected which implement in the most complete manner advantages of the shock-strut double-chamber structure. Mathematical description of these shock-struts is discussed. In the parts one and two of the paper two structural kinds of the double-chamber shock-struts are described in detail. All operational modes are described for each kind of the shock-struts. An equation is derived for relationship between velocities of shock-strut piston and floating piston as well as a computational algorithm is suggested for state parameters. Qualitative conclusions are obtained fr om a structure of this equation about operational features of the shock-strut kinds. The part three contains calculation results to compare both kinds of the shock-struts for the cases of landing shock and cross over of runway irregularities. A vertical velocity of impact is varied for the landing case whereas height of irregularities and taxing speed are changed for the cross over case. Areas of preferred application are revealed for both kinds of the shock-struts. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Orlov V. N. About a teachnique to solve approximately matrix differential Riccati equations. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 128-135. A technique is suggested to solve approximately matrix Riccati equations. The technique consists of approximate solution of the equations in their analyticity region and some neighborhood of moving singular solution point as well as algorithm to search the moving singular solution point with prescribed precision. This algorithm is based on necessary and sufficient existence conditions for singular solution points. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sorokin A. E., Shcherbakova E. A. A technique to evaluate financial and economical condition of aircraft industry enterprises. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 76-82. Methodological science-based tools are suggested to analyze and assess financial sustainability of aircraft industry enterprise using differential approach to the assessment. An approach are presented within the bounds of the methodological tools to reveal some optimal level of financial sustainability of the enterprise subject to peculiar features of aircraft industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stepanenko S. A. Gas dynamics and interphase heat exchange foe supersonic heterogeneous flow inleaking on some obstacle. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 34-39. High-speed nonisothermic heterogeneous flows become to apply increasingly in innovative technologies. It is a very topical problem now to study in-depth a nature of coatings, which are obtained by means of interaction between high-speed heterogeneous flows and surfaces. An approximate mathematical model is suggested in the paper to analyze these interactions. In addition the problem is solved for supersonic heterogeneous flow inleaking on some flat obstacle. An analysis of inertial motion modes for particles in shock and pressurized layer has important practical bearing on coating technologies basing on usage of supersonic heterogeneous flows to form thin coatings. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shtyrlin A. F. Focusing properties of a single emission cell for colloid electrojet engine. Aerospace MAI Journal, 2008, vol. 15, no 5, pp. 95-100. Focusing properties are analyzed for electrostatic liquid atomization from pointed edges of emission electrodes with diameter values from 2.24 mm to 3.22 mm. A physical mechanism of the process is studied by means of modeling for electric field in an emission cell, trajectory construction for charged drops and determination of annular divergence for a beam. Experimental data are obtained basing on measurements of current distribution in multisectional target with overall capture angle equal to 120°. Experimental relationships are presented for a mean annular divergence value as well as for a coefficient of vector-angular energetic losses subject to unit rate of flow for some unit length of emission edge. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ageyeva N. G., Kuznetsova A. B. A technology for selection of basic units basing on a balanced set of performance indexes . Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 89-95. Stages of management strategy development cycle are substantiateв for the case of differentiation in decision-making levels. These stages are based on some balanced set of performance indexes. A technique is suggested to interconnect the stages of management strategy development cycle and the decision-making levels. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Antonov G. N., Vlasov O. G. Systems analysis and safety in technology-related field. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 139-144. The concept of safety is discussed as one of the most significant properties for complex man-machine systems. An importance of the safety concept is demonstrated by means of examples from aviation, astronautics and navy fields. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bespalov V. А., Ghotseliuk T. B., Laznenko S. А., Matveyev K. А., Chaplygin V. N. A computational evaluation of surface fracture growth and stress intensity factors for standard parts with complicated geometry. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 111-117. A technique is suggested to estimate numerically values of surface fracture growth and stress intensity factors (SIF) for standard parts with complicated geometry. A module is developed basing on the ANSYS finite-element software package. This module allows to generate automatically a net of singular elements and to evaluate SIF distribution along the front of elliptic-shaped fracture. Numerical and experimental investigations are carried out for fracture growth duration in regard to structural elements of airliner high-lift devices. It is demonstrated that the proposed technique for finite-element SIF and crack growth resistance evaluation provides results, which are acceptable with respect to accuracy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I. Geometric techniques for analysis of self-oscillations in throttled liquid rocket engines . Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 50-52. A geometric representation of nonlinear system dynamics in phase space is one of the most evident and significant techniques for investigation of system instability. A state of the nonlinear system is represented by point in the phase space at each moment of time. While the state changes the point generates a phase trajectory in the space. The phase trajectories describing transition of the system is named as its phase portrait. The phase portrait provides full and clear view of the nonlinear system dynamics. Basing on these considerations some geometric techniques are discussed to analyze self-oscillations in throttled liquid rocket engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bokov N. А. Methods and tools to simulate business processes at implementation of corporate information systems . Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 96-104. An approach to business process modeling is suggested basing on synthesis of functional and operational techniques for organizational design. A validation of the approach is accomplished by means of analysis for problems and processes, which take place at implementation of corporate information systems. An enterprise resource planning system for telecommunication company is discussed as an example to demonstrate effectiveness of the approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bordakov V. N., Ermolov A. F., Sinitsyn A. N. An ejector system for gas purification. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 53-61. Experimental results are presented to evaluate a liquid-gas ejector system for gas purification. The considered system is intended for gas-phase mixture decontamination of poisonous components. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lepeshinskii I. A., Zuyev Y. V., Kirdsook S. ., Istomin Е. А. A gas-turbine engine as a source of working substance in long-range large-power fire suppression system . Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 44-49. An approach is discussed to use a gas-turbine engine as a source of working substance in long-range large-power fire suppression system. An analysis is carried out to evaluate influence of the engine scheme and its main parameters on efficiency of the fire suppression system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korshakovsky S. I., Krasnenkov M. А. A generation of electrical signals for nondestructive inspection of turbine parts in aerospace engineering . Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 118-125. A technique is suggested for nondestructive inspection of electroconductive turbine parts in aerospace engineering. The technique is based on generation of static magnetic field in a checked area and transformation of arising secondary magnetic field of whirling currents in this area into electric signals. The obtained results allow to define the form of these signals corresponding to typical defects in rotor blades of the turbine. The techniques of mechanical defect examination, temperature inspection, vibration and other factors supervision implementing for engine parts enable to provide operational emergency protection of the engine. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kotelnikov M. V., Anickin N. А. A mathematical modeling of collisionless plasma flow around a cylindrical body. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 105-110. A mathematical modeling is accomplished to investigate physical processes in the near-wall region of a charged cylindrical body, which is located in low-density weakly ionized plasma. First of all the plasma at rest case is discussed then an influence of broadside directional velocity is taken into account and thereafter combined influence is analyzed for broadside directional velocity and magnetic field. Obtained results cover qualitatively features of own satellite atmosphere or some of its cylindrical parts streamed with collisionless plasma flow. These results are useful too for diagnostics of plasma by means of cylindrical probes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lianzberg V. P. High-pressure acrylic windows with translucent shell-formed unit made of organic glass. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 5-9. An investigation is carried out to enhance a loading capacity of high-pressure acrylic windows with translucent shell-formed unit made of organic glass. A literature survey is presented with analysis of contemporary structure versions for such windows. Main ways to enhance strength of the windows are outlined. Some new window versions are proposed which are studied experimentally. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panteleyev A. V., Letova T. А., Kondakov V. K. “Optimization techniques through examples and tasks” computer-based educational unit as a tool to support self-instruction of students while studying the “Optimization techniques” course. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 80-88. «Optimization techniques through examples and tasks» computer-based educational unit is developed as a tool to support self-ins a tool to support self-instruction of students while truction of st consists of the «Optimization techniques through examples and tasks» textbook and a teaching program associated closely with the textbook issued by the «Higher School» publishing house in the year 2004. The teaching program is developed in the TBBuilder 2 software environment basing on the requirements to the educational units. udents while studying the «Optimization techniques» course. The unit consists of the «Optimization techniques through examples and tasks» textbook and a teaching program associated closely with the textbook issued by the «Higher School» publishing house in the year 2004. The teaching program is developed in the TBBuilder 2 software environment basing on the requirements to the educational units. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bomas V. V., Portonet D. S. Preference formalization in the DSS/UTES decision support system by means of default preference function. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 68-74. A technique is suggested to generate users preference function in the DSS/UTES decision support system. The technique is based on preliminary formation of some default version of the preference function. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Protasov V. I., Maximov N. А., Potapova Z. E., Sincha D. P. Quasi-associative search of pictures in large data bases. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 62-67. A geometric technique is considered to search digital terrain pictures according to a graphic image corresponding some representative part of the desired picture. The technique is based on ring filters. Each picture is associated with some hash, which describes uniquely this picture. The hash is used for quasiassociative search in large data bases. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Raznoschikov V. V. Efficiency evaluation for using of cryogenic and gas fuels in propulsion systems of passenger airplanes. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 35-38. Some approaches and techniques are discussed to evaluate usage efficiency for cryogenic and gas fuels. This problem is solved in regard to propulsion systems of passenger airplanes basing on analysis of the aircraft-propulsion-fuel triad. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Talalayev A. A., Rochev A. S. A technique to evaluate influence of flow coefficient at tests of multinozzle assemblies by means of gas-dynamic differential test bench. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 39-43. A technique and a calculation scheme are proposed to evaluate difference between flow coefficient values for some compared jet nozzles with various configurations and dimensions of their inlets and throats. This evaluation is based on experimental results obtained by means of gas-dynamic differential test bench. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Toropov G. P., Khartov S. A. A mathematical model of jet expansion inside vacuum chamber for plasma accelerator. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 25-34. A mathematical model and calculation of gas distribution results is presented for jet expansion inside vacuum chamber of operating plasma accelerator. A numerical reconstruction is carried out for spatial distribution of ionic current in the jet subject to a charge — exchange process provided with interactions between accelerated ions and residual gas inside of the vacuum chamber. A thrust of the accelerator is estimated basing on corrected measurement and calculation results for the ionic currents. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chouen B. T., Krylov S. S. A shader graphics based system for generation of dynamical three-dimensional images intended for Internet application. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 75-79. A new approach is suggested and discussed to generate three-dimensional animated images intended for Internet applications. The approach uses a shader procedural representation of animation effects. A principal advantage of the approach consists in rather small data volume for files obtained as a result of image generation. An effective image transfer via data channels is provided in such conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shydakov V. I. An investigation of ground effect influence on aerodynamic characteristics and air stream parameters for lifting rotor of helicopter. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 10-18. Analytical relationships are derived basing on mathematical modeling to evaluate aerodynamic characteristics of helicopter main rotor operating near ground surface. These relationships allow to calculate thrust and power for the rotor as well as basic parameters of air stream namely streamlines, velocities and pressures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shtyrlin A. F. A generation of unipolar electric charge in electrostatic source of liquid particles for colloid electrojet engine. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 126-138. Applied-physics and theoretical foundations are discussed to generate unipolar electric charge in electrostatic source of liquid particles for colloid electrojet engine. Liquid working medium of the engine is investigated as cold electrolytic plasma. A decompensation of spatial charge for electrolytic ions as well as generation of unipolar electric charge takes place in the plasma upon action of strong electric field. An analytic solution is suggested to solve a calculation problem for specific charge of the particles depending on liquid properties, spraying electrode polarization, field parameters and consumption of working medium. A comparison for calculated and experimental data is carried out. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shumilov I. S. Damping of airplane control surfaces oscillations in case of activated or deactivated hydraulic system. Aerospace MAI Journal, 2008, vol. 15, no 4, pp. 19-24. An analysis is carried out to reveal an influence of hydraulic actuator operation mode on a motion stability of aircraft control surfaces. Some recommendations are suggested to choose a damping value for these control surfaces in case of activated or deactivated hydraulic system as well as design solutions ensuring needed damping level for these control surfaces. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Amelkin A. S., Kiansky T. N. An influence of a spline connection on geometrical parameters of above-placed bearing. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 90-94. Rolling-contact bearings are placed often in spline connection zones of gas-turbine engines. The spline connection deforms essentially the geometry of bearing mounting surface as a result of torque transfer. An analysis is carried out for this phenomena influencing unfavorable on operation conditions of the bearing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I. An anomalous increased permeability phenomenon for fine-pored material (membranes). Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 95-97. A speed of manufacturing processes, gas and liquids clean-up for example, determined by permeability through porous materials and membranes can be raised essentially by means of self-oscillation generation for simultaneous gas and liquid flow. It is possible to use the proposed techniques for development of advanced technologies related to various application problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I. About computation of bifurcational parameters for choking liquid jet engines . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 208-211. Instability of dynamic systems with essentially nonlinear characteristics is very complicated problem to solve it. This problem is solved in the design process of various aerospace vehicles and power systems. A choking liquid jet engine is an example of the systems. The analysis of such systems is carried out by means of harmonic balance technique or using qualitative theory of differential equations. Yet another approach is phase portrait formation for the system. Bifurcations must be analyzed in addition to the phase portrait for the system with complicated nonlinearities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Borovik I. N. A mathematical model of specific cost for payload launch into the target orbit by means of reusable upper-stage rocket. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 44-50. A mathematical model is built to analyze specific cost for payload launch into high-energy target orbits by means of reusable upper-stage rocket. Suitability conditions are revealed basing on the model for design and maintenance of reusable upper-stage rockets. A transition from 200 kilometer low earth orbit into some geotransitional orbit is assumed as a basic operation. Main requirements are formulated to choose key design parameters for propulsion system of the reusable upper-stage rocket. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brekhov O. M., Tee Khan -. . An analytic model for basic estimation of upgrade instant time for the software of a remote real-time computing system . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 147-153. Analytical models with various detail levels are suggested for software upgrade processes. The collection of these models provide evaluation of time needed for the upgrade taking into account possible bugs in the new version of the program. Besides the collection makes it possible to verify models mutually. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko N. N. A system analysis application for developing of economic-organizing mechanism to educate manpower resources for aircraft industry . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 191-202. Modern aviation industry enterprises become more and more exacting to staff selection. The staff education efficiency by means of traditional techniques does not meet present market requirements. It is for this reason that a combined industrial and educational area is discussed. The area is a complex combined system (CCS), which includes various hierarchical levels. The ultimate goal of the CCS is to provide competitive products while training highly qualified staff. Due to methodological approach proposed in the article a possibility arises to reveal, describe and investigate basic units of the combined industrial and educational area, such as university and aerospace industry enterprise, as well as a collection of system relations. This approach enables also to obtain generalized schemes of cost-effectiveness analysis and assessment for the CCS basic units. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Glukhov A. V. An analysis of schemes applied by domestic and foreign air transportation companies for acquisition of aircraft . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 203-207. An analysis of international financing experience is carried out as applies to aircraft purchase by means of leasing. Aircraft acquisition schemes are described and analyzed for domestic and foreign airlines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidov A. S., Kashelkin V. V. An estimation of absorption coefficient value for some material basing on creep cyclic tests. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 69-73. Some techniques are described to reveal internal friction characteristics for constructional materials. These techniques are based on results of cyclic creep tests. An approach is suggested to evaluate absorption coefficient values using the Andrade creep model and the numerical value of stress relation for the cyclic creep tests with a partial unloading for which there are no accumulation and relaxation of deformations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Diachenko D. A. An infuence of structural parameters describing mixing zone of annular combustion chamber for gas-turbine engine on non-uniformity of temperature field at outlet of the chamber. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 51-54. Experimental investigations are described for an annular combustion chamber of gas-turbine engine. The investigations are aimed to decrease a hoop temperature distribution before the turbine on a combustion chamber test bench. Ensuring of sufficient penetration depth of air jets into the flow in a mixing zone is used to assure required temperature distribution. Relations between hoop non-uniformity of temperature field and some influencing factors are analyzed. These factors include air consumption, hole pitch as well as relative momentum for delivered air on conditions that temperature field is uniform before the mixing zone. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ermilov Y. I., Ravikovich Y. A. An experimental investigation of ultimate load-carrying capability for leaf-type axial air foil bearings intended for low-sized high-speed turbo-machines. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 74-82. An experimental investigation is carried out to reveal ultimate load-carrying capability for leaf-type axial air foil bearings intended for low-sized high-speed turbo-machines. A new nondestructive technique is suggested to estimate this characteristic essentially simplifying experimental work. A test rig is described, which is aimed to evaluate ultimate load-carrying capability for axial air foil bearings. Some test results are presented for axial air foil bearing with 37 mm outer diameter and maximum rotation per minute up to 90000. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanisov V. Y. Methodological principles of mixed financing of research and development to build armament and defense technologies . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 178-190. Methodological principles are presented for mixed budgetary and off-budget financing of research and development to build armament and defense technologies. Practice-proved implementation schemes are discussed for organizational and mathematical models and techniques based on the suggested principles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov V. M. Conceptual foundations of orbital servicing for advanced automatic space vehicles . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 5-7. Some results are discussed related to research of possibilities to implement an advanced technique intended to maintenance support for new-generation space vehicles by means of servicing immediately on their operational orbits. A concept is suggested to introduce servicing activity. Jobs are formulated for a servicing space infrastructure as well as requirements for servicing tools. A composition for the space system is determined. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kessaev K. V. About thermodynamics of resonance tube. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 15-24. As applied to a problem of gas dynamic ignition of rocket propellant we analyze the heating-up mechanism inside a deep cavity (resonance tube) when a jet of underexpanded gas enters in it. Analysis of heat exchange between gas and cavity walls shows that there are two stages of the process: on initial stage with a swift temperature increasing the heating is governed by shock-wave oscillations inside the tube and an influence of heat exchange predominates on the next stage with slow temperature increasing. The speed and level of heating are increased when the resonance tube inlet is made in form of supersonic diffuser. Experiments confirm the analysis results. Recommendations for design of effective igniter are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Knyaz V. A., Ilya V. Krupennikov I. I., Sharonov A. V. Video measurements and a correlation stereo indentification problem solving using the gradient approach and pyramids of stereopairs. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 98-103. Full time needed for stereo identification is intolerably large in problems of stereopair-based video measurement aimed to motion control for dynamic systems. An algorithm is suggested to overcome this situation. The algorithm uses some gradient approach and an image pyramid to perform stereo identification for pixels obtained from two cameras with mutually known orientation parameters. The algorithm is implemented on experimental facility equipped with CCD cameras. The resolution is 640×480 pixels and the frame rate is 30 frames per second for the cameras. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korshikov S. B. Algorithms for recovery of assembly links in regard to parametrical changes of assembly components . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 212-218. Assembly links are considered for assembly structures. Algorithms are suggested to recover these links after parametrical changes in geometry of assembly components. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Levsky M. V. Spatial orientation control with minimum fuel consumption for spacecraft . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 129-140. An optimal control problem for a spatial maneuver is described and solved to change a spacecraft orientation with minimum fuel consumption. It is shown that optimal solution belongs to the two-impulse control class. The spacecraft orientation maneuver under this control performs as a free (uncontrolled) motion. Control techniques based on the free trajectories technique are proposed to enhance implementation accuracy for predefined spacecraft angular attitude. The synthesized controls are invariant both to external disturbances and parametrical errors. Results of mathematical modeling are given to demonstrate high efficiency of the proposed control algorithms as well as their practical feasibility. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Beresnev A. G., Loghunov A. V., Loghachiova A. I. Some problems related to refinement of high-temperature alloys produced by means of granular metallurgy techniques. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 83-89. Main development directions are discussed for granular metallurgy of high-temperature nickel alloys. The development provides refinement of produced materials as well as stability increasing for their operational properties. These enhancements are related to various stages of the production cycle including manufacturing of granules; filling, compaction and sealing of granules in capsules; separations, dissemination, gas-static compaction of capsules and deformation by means of new chrome-based stamp materials. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lukovnikov A. V. A conceptual design of aircraft propulsion systems in multidisciplinary statement. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 34-43. A multidisciplinary methodology is suggested for conceptual design of aircraft propulsion systems. This approach is aimed to research stages of aircraft design processes. A composite mathematical model is developed for aircraft-propulsion systems intended to generation of optimal preliminary propulsion design basing on performance indices for various kinds of aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chaika N. K., Klonitskaya A. Y., Semenov P. N., Safonov I. V., Pimenov A. N. A diagnostic technique to analyze causes of unprofitability and low profitability for enterprises of aircraft industry . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 165-172. A diagnostic technique is suggested to analyze causes of unprofitability or low profitability for enterprises of aircraft industry. The technique is based on evaluation of tax proceeds into various level budgets according to data from tax accounts. A kind of unprofitable activity is revealed basing on comparison of economic efficiency indices for the enterprise. An enterprise classification by unprofitabilty kinds is carried out by means of calculation for incomes missed out of the various level budgets. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makarov M. I. Conceptual foundations of advanced computer-aided monitoring system for the Russian space infrastructure. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 120-128. Standard tasks, architecture, and operations of advanced computer-based system for complex monitoring of the Russian space infrastructure objects are described. This system is aimed to ensure the proper safety of a space activity | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makhnenko Y. Y. An application of regularizing data processing technigues for navigation of geostationary satellites . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 8-14. Application features are considered for regularizing techniques intended to processing of measurement data associated with navigation of geostationary satellite. This task is classed as an ill-posed boundary problem. Some navigational alternatives are analyzed which depend on necessity to expand a repertoire of adjustable parameters. The alternatives are location-dependent too for the satellite in some specific point relative to a ground station. They depend also on range measurements basing on the only station. A conclusion is obtained about application efficiency for the versions of the considered regularizing techniques to ensure a needed navigation accuracy and reliability subject to minimum implementation costs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Merkishin G. V. A generation of image description basing on binary relations . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 104-113. A description problem is discussed as applies to geometric and reflective properties of observation object for the purpose of its recognition. An object representation is introduced as a collection of most meaningful structural units and their binary relations. A symbolic language is suggested as well as a system of differential equations describing a movement of the information structure throughout the process of its generation, refinement and evolution. Basic processes and structure of composition synthesis are defined for information parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Molchanova S. Y. A simulation of induction motor drive with adaptive vector cobtrol by means of the CASPOC software environment . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 141-146. A synthesis problem is considered as applies to control laws and parameters for induction motor drive with adaptive control basing on vector voltage inverter. The model which is used to solve the problem is generated in the CASPOC software environment. A simulation is carried out for various performance indices and control constraints. Regulation parameters are presented with logical functions to implement microprograms for some dedicated microprocessor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nadiradze A. B., Khartov S. A., Shaposhnikov V. . Investigation of ionic erosion process within stationary plasma thruster. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 25-33. An analysis and experimental data are presented to reveal ionic sputtering features of ceramic chamber surfaces for a stationary plasma thruster (SPT). An important conclusion is made according to the obtained results. Namely, the main feature of ionic erosion (sputtering) of ceramic materials used in the SPT is some surface heating up to a temperature under which an exponential growth comes for the sputtering coefficient. Data about selectivity of the sputtering mechanism are obtained too. This mechanism causes decreasing of nitrogen percentage in the SPT chamber surface layers. A procedure is suggested to test ionic sputtering tolerance of material samples during the SPT trials. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ratnikov S. . An application of vortex tube enhancing of gas-turbine plant efficiency. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 63-68. A thermodynamic analysis is carried out to evaluate efficiency of gas-turbine plants (GTP), which include a vortex tube to enhance GTP efficiency and to decrease energy losses in cooling system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybnikov S. I., Hoang Minh Dac -. . An analytical design of optimal control laws for aircraft short-period longitudinal motion according to multivariant generalized work performance index. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 154-164. An analytical design of optimal regulators is discussed according to multivariant generalized work performance index. This approach is applied to parametric synthesis of control laws for short-period longitudinal motion of hypothetic middle-range airliner. A set of optimal control systems is generated with various response speed and energetic control costs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Spirin V. G. Thin-film multilevel switching cards with thick-film polymer isolation . Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 114-119. Some design-manufacturing versions of thin-film multilevel switching cards are presented. These versions use isolation of conductive levels by means of thick-film organic dielectric. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sysoyeva I. V. Accounting and analytical support for risk capital management in regard to aircraft industry enterprises. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 173-177. A risk capital operates in aircraft industrial sector. It means that investments are used with a heightened risk as compared to usual conditions. A technique is suggested to manage the risk capital of aircraft enterprises. The technique is based on evaluation of venture risk treated as accumulated market and innovation risks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lepeshinskii I. A., Zuyev Y. V., Tsarenko P. B. An investigation of interaction between subsonic high-concentrated two-phase flow and partially permeable body. Aerospace MAI Journal, 2008, vol. 15, no 3, pp. 55-62. Results of theoretical and experimental investigations are considered to analyze an interaction between subsonic high-concentrated two-phase flow and partially permeable body. A new physical model is formulated for this problem. Values of the model coefficients are determined, which characterize energy dissipation as well as a percentage of gas entrained with particles into partially permeable body. Recommendations are suggested about gas-dynamic probe operations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakhshiyan B. T., Goryainov A. V. A skeleton algorithm to solve linear programming problems and its applications for optimal estimation problems. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 5-16. A new algorithm is proposed to solve ordinary and multiparameter (generalized) linear programming problems. The algorithm guarantees absence of almost degenerate iterations and does not require inversion of matrices. The algorithm was tested to solve optimal minimax estimation problems for polynomial and trigonometric models. Some examples are presented to demonstrate an effectiveness of the algorithm in comparison with the standard simplex method. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Borisov A. V., Skvortsova N. N., Stefanovich A. I. Information technologies for HMM identification of plasma turbulence processes. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 17-27. An information technology (IT) providing a phenomenological model of turbulent plasma density is presented. Applicability of this IT is demonstrated by both some synthetically modeled data and real measurements from the TJ-II stellarator (CIEMAT, Madrid, Spain). | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bortakovsky A. S., Pegachkova E. A. Control synthesis for active satellite stabilization basing on necessary optimality conditions for logical-dynamical systems. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 28-35. An active stabilization problem with minimum fuel consumption is considered for a satellite. The solution of the problem basing on its classical statement provides a minimizing sequence with infinitely many engine burns during infinitely short time intervals. However, this infinite impulse strategy is practically unreliazable. Hence it is suggested to take into account the number of switches, solving the problem within logical- dynamical systems (LDS) class. An approximate solution is derived basing on necessary optimality conditions for LDS. These necessary conditions are compared with the Pontryagin maximum principle. Results of some test calculations are discussed as well as their practical applicability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dmitriev S. S., Kuznetsov E. B. Optimal parameterization for systems of Integra-differential-algebraic equations with delay argument. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 36-44. A numerical solution of initial value problem for nonlinear systems of integro-differential-algebraic equations with delay argument is investigated using the method of solution continuation with respect to a parameter. Necessary and sufficient conditions are proved to transform the problem to the optimal argument. The optimal argument is the arc length counted along the integral curve of the problem. Numerical examples demonstrate efficiency of this approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kan A. V., Kan Y. S. Guaranteeing confidence estimation of parameters for a set of distributions. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 45-50. A problem under consideration is parametric estimation based on some sample of finite size in the case where the Central Limit Theorem (CLT) is applied to construct asymptotic confidence intervals. It is suggested to construct guaranteeing confidence intervals taking into account an inaccuracy of the CLT normal approximation. Such intervals are constructed explicitly for some unknown parameter of the exponential distribution and also for some unknown probability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kibzun A. I., Matveyev E. L. A parallel algorithm to optimize a fractile function. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 51-58. A parallel algorithm is suggested to minimize a quantile function. The algorithm is based on decentralized algorithm for the quantile estimation. The almost sure convergence is proved for the algorithm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kibzun A. I., Miroshkin V. L. An approach to computer simulation of motion for a group of connected objects. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 59-65. An approach is suggested to simulate a motion for a group of connected objects. This approach is based on representation of motion for some object as its coordinate system motion. Tree-type structures are constructed to describe relations between coordinate systems associated with the objects incorporated into the group. The tree structure specifies some order on the set of coordinate systems to simulate interconnections between them. An algorithm is presented to generate tree structures needed to describe relations for coordinate systems. An application of the tree structures are demonstrated to model two types of interconnections between coordinate systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krasinsky A. Y., Khalikov A. A. A computer-aided analysis of stabilization problems for steady motions of mobile robots as nonholonomic systems. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 66-76. Some possible statements are discussed for stability and stabilization problems related to steady motions of nonholonomic systems. A structure of nonlinear vector equations is analyzed to describe perturbed motions as well as a type of stability achievable after stabilization for various statement of the problem. A software product is described to realize in some symbolic form an algorithm to generate coefficients for stabilizing control and estimation systems. An application of the product is discussed to solve the stabilization problem for steady- state motion of unicycle model. Lagrange variables are used in the problem and stabilizing coefficients are calculated by the Krasovsky method for optimal stabilization problem associated with assigned linear controlled subsystem. As an example a transient process (unicycle tilt angle subject to time) is demonstrated for the unicycle motion under the action of the synthesized control. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuznetsov Y. V., Shevgunov T. Y., Baev A. B. A parameter estimation for linear model of electromagnetic field scattering within microwave devices. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 77-89. A linear model is presented to describe electromagnetic field scattering processes within microwave devices. The model consists of dynamic and non-dynamic linear systems. An impulse response estimation technique is considered for given input and output signals obtained by numerical time domain simulation of the scattering process. A new stability criterion is suggested to perform a posteriori estimation of dynamic model order as well as techniques to implement this criterion. The matrix pencil method is applied to estimate parameters of the dynamical system in time domain. The vector fitting technique is used to estimate linear model parameters in frequency domain. An identification problem for microwave coplanar resonator is discussed as an example basing on simulation results obtained by means of transmission line matrix (TLM) technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lebedev M. V., Semenikhin K. V. Minimax estimation of random vector in the presence of arbitrarily correlated disturbances. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 90-104. A minimax estimation problem with mean-square criterion is discussed for stochastic observation model with white-noise and arbitrarily correlated disturbances. The least favorable covariance matrix is derived for the arbitrarily correlated disturbance. The minimax state estimate is obtained by means of this matrix for the analyzed system. The minimax algorithm is compared with other estimation techniques. Some results of numerical simulation are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pankov A. R., Ignashchenko E. Y. Minimax-adaptive optimization of linear statistically uncertain models. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 105-112. A quadratic programming problem is discussed in case of optimized model with inexact parameters. Analytical properties of minimax solution are investigated in regard to a given uncertainty set for unknown parameters of the problem. A numerical algorithm is suggested to obtain the minimax solution of the problem. Adaptation techniques are considered as applies to minimax solution. These techniques are based on statistical estimates for uncertain model parameters. Some numerical simulation results are presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panteleyev A. V., Apostol N. P. Techniques and software for modified genetic constrained optimization algorithm with binary encoding. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 113-122. The global constrained optimization problem is considered as applies to multivariable functions. It is suggested to solve this problem by means of genetic algorithm with binary coding. Recommendations are discussed to apply the algorithm. A software implementation of the algorithm is described as well as numerical experiment results using a bundle of test functions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybackov K. A. Sufficient optimality conditions for a problem of centralized control for stochastic multiple-structured systems. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 123-131. An optimal control problem is considered for nonlinear stochastic systems with random structure under incomplete state information. Sufficient optimality conditions are derived as well as relationships to obtain optimal control both for general case of minimized functional and for optimal at the average control. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sinitsyn I. N., Sinitsyn V. I. An ellipsoidal analysis of distributions in stochastic systemsons in stochastic systems. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 132-141. A development is suggested for theory of ellipsoidal analysis in regard to one- and multidimensional distributions in differential stochastic systems. The theory is discussed as applies to problems of aerospace engineering. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sirotin A. N. An exact analytical description of reachablity set for asymptotically stable linear discrete systems with constrained l1-norm scalar control. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 142-146. A linear stationary system with discrete time and scalar control is considered. It is assumed that the control is restricted on -norm, i.e. the sum of modules of control actions on each pitch is restricted and the Kalman rank condition is satisfied. A construction problem is investigated in regard to the reachability set for such class of systems. The investigation is carried out for systems with spectral matrix radius less than unity. It is shown for this case commonly encountered in practice that the required set admits exact analytical description. The set represents some convex restricted closed polyhedron with a finite number of vertices. An estimate is obtained for the number of polyhedron vertices. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khrustaliov M. M., Rumyantsev D. S. Synthesis of optimal control strategies for flexible satellite in case of information constraints. Aerospace MAI Journal, 2008, vol. 15, no 2, pp. 147-154. A behavior of satellite with elastic rod is investigated. The satellite moves on a near-earth orbit and it is stabilized by means of jet engines. It is known space is rather «quiet» environment in terms of vibrational loads acting on objects remaining in it. Therefore structure element stiffness can be very low for a spacecraft. Effects related with action of gravitational field gradient on the satellite are studied. The study is curried out for a small elastic displacement case. The results obtained in the paper can be valuable both for satellite control theory and applications. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bobe L. S., Gavrilov L. I., Kurmazenko E. A. Development prospects for regenerating life support systems in regard to long-term manned space flights: A preliminary analysis . Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 17-24. Capabilities evaluation is carried out to develop a space-crew integrated regenerative life support system (IRLSS) intended for accomplishment of long-term autonomous spaceflights to the Mars and to the Moon. Features and functions for the IRLSS are discussed as well as engineering requirements and constraints in regard to spaceflight conditions. Preliminary analysis results show that development of the IRLSS for interplanetary spaceflights can be based partially on design choices and engineering processes used in modern systems for orbital flights. Some possible concepts are introduced for advanced regenerative water supply systems and for air revitalization and monitoring systems in the spaceflight conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bordakov V. N. Experimental investigation for alcaline hydrolysis of lewisite within a pilot plant. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 77-86. Experimental investigation results are discussed for parameters of alcaline lewisite hydrolysis within a pilot ejector chemical reactor. Stoichiometric equations are derived and validated experimentally to describe alcaline lewisite hydrolysis within ejector. Optimal conditions are obtained to conduct appropriate technological process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galeyev А. G. Development of hydrogen-fueled rocket engines and power plants with consideration of corresponding safety problems. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 56-63. Some development aspects are considered for 11D56, 11D57, RD-0120 hydrogen-fueled rocket engines as well as for various power plants against several foreign-made engines. A significance of simulation and autonomous tests for assemblies and systems is discussed with consideration of corresponding safety problems. Basic principles are analyzed to provide ground tests safety for rocket engines and power plants. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khaustov A. I. Theoretical and experimental investigations of pumps for pressure systems of aerospace vehicles. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 70-76. Dynamic characteristics are investigated for pump units, which are parts of pressure systems of aerospace vehicles. An influence of the pump is discussed on pressure and flow pulsations as well as on time shift of the pulsations. Besides relationship are studied between these pulsations and pressure characteristic shape, plus geometric and operational pump parameters in regard to cavitation-free mode of operation. Experimental data are presented for impeller machines with various pressure characteristic shapes. It is demonstrated that the steeper a pressure characteristic shape the stronger a cutting of intake pulsations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rodchenko V. V., Gusev E. V. Modeling of preparation processes for upper-stage rockets to test them on engineering test bed. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 3-7. Modern and advanced spacecraft and rocket systems are developed basing on high-technology systems, robotics, automation tools, computers etc. Therefore spacecraft and rockets tend to be more and more complex in terms of structure and maintenance. These circumstances demand higher requirements for professional skills of maintenance staff. However a personal training is based until now on full-scale systems as well as on spacecraft and rocket mockups and simulators. This equipment includes obsolete computers in most cases and it has insufficient training capabilities. Advanced software-based simulation systems allow to enhance effectiveness of training processes for the spacecraft maintenance staff. Some features are discussed for these systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Novikov A. N. Multiobjective optimization of current activities financing for enterprises. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 117-125. An approach is suggested to realize strategic-oriented optimal management for financing of industrial enterprise current activities. The management goal is a business solvency of the enterprise. An appropriate multiobjective optimization problem is formulated and solved using game theory and linear programming techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Berns V. A., Bobryshev A. P., Prisekin V. L., Samuilov V. F. Coaxiality monitoring for deflecting surfaces basing on vibration tests. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 87-91. A technique is suggested to monitor coaxiality for aircraft wing deflecting surfaces. The technique is based on analysis of characteristics variations for resonance oscillations of the surfaces. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balyk V. M., Kalutsky N. S. A statistical synthesis of stable design choices for flying vehicle design processes in conditions of multiple-factor uncertainty. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 29-36. Stability conditions are formulated for design decisions in respect of multiple-factor uncertainty caused by target and environment states. Considerations are introduced for design choices, which are stable to the multiple-factor uncertainty. These choices are presented as dynamically varying statistical sampling. Regularization rules are derived for initial set of the design choices basing on the Lipschitz condition. A toy missile control problem is solved using the regularization rules to demonstrate peculiarities of selection process for the stable design choice in conditions of multiple-factor uncertainty caused with the target behavior. A layout is suggested to synthesize statistically stable algorithmic and software control solutions under the multiple-factor uncertainty. An appropriate software tools are developed to support design of stable control laws for unmanned vehicles operating in multiple-factor uncertainty conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baranov V. N., Gorbatenko S. A. Mathematical models of flexible cable to investigate towed systems. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 136-144. Various mathematical models of flexible cable are considered. These models can be used to design nautical and aerospace towed systems. They allow to analyze steady and unsteady motion modes for towed systems as well as to build control algorithms for such systems.The models can be applied also to conduct analysis of full-scale tests results for towed systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorbatenko S. A., Baranov V. N. A control law synthesis for multidimensional dynamical systems basing on inverse dynamics problem techniques. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 109-116. A synthesis of control laws for multidimensional systems using inverse dynamics problem techniques is considered. These control laws are invariant to external and parametric disturbances. The suggested synthesis technique is easy-to-use and effective. Requirements and conditions can be involved to take into account peculiarities of applied problem to be solved. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Degtiarev S. A., Leontiev M. K. . Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 64-69. Results of dynamical properties simulation are discussed for a multiplication unit used in compressor test bed. Investigations are carried out both in linear and nonlinear statements. A linearization is performed for operational modes typical for the multiplication unit. Computations using nonlinear and nonstationary model allow to reveal stability boundaries for plain bearing based output shaft of the multiplication unit. The boundaries are computed subject to a loading, which is propagated by the unit from a gas-turbine drive to the compressor to be tested. Boundary conditions are also taken into account for the ends of input and output shafts of the multiplication unit. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zolotov A. A., Nepochatykh D. A. A choice of spacecraft design parameters subject to operation efficiency requirements. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 37-43. A technique is suggested to choose spacecraft design parameters subject to operation efficiency requirements. Recommendations are formulated to evaluate effectiveness and to normalize reliability for spacecraft onboard equipment. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Konstantinov M. S., Petukhov V. G. Stability maintaining for orbital configuration of spacecraft system in high elliptic orbits. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 8-16. High-elliptical Molniya type orbits can be used for regional and global satellite communication systems as well as for terrestrial monitoring systems. Such systems can be considered as an addition to geostationary satellite systems and as an alternative to these systems in some cases. A serious shortcoming of such systems is strong degradation of orbital elements for the satellites and some obstacles to provide stability of the satellite system. An approach is suggested and an algorithm is developed to ensure stability of the satellite system on high-elliptical orbits. It is shown that average characteristic velocity consumption can be reduced to a yearly level of 55 m/s to provide stability for a satellite system consists of typical spacecraft with stationary plasma thrusters of the SPT-70 type. This estimation does not take into account design restrictions, for example on arrangement of engines. This value is very close to demanded characteristic velocity consumption to maintain orbit for a geostationary spacecraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korshikov S. B., Padalko S. N. An effective parameter distortion technique for two-component geometri model to secure transfer it within open data transmission channels. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 126-135. A technique is suggested to secure design information containing in forms using in CAD/CAM/ CAE systems. The technique is based on minimization of open text length as well as on a «distortion- restoration» procedure to conduct design data transfer within open data transmission channels. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveev Y. A., Lamzin V. V. A constraint-based technique to choose design parameters of spacecraft versions meant for earth remote sensing. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 44-55. Methodological aspects are considered for design investigations to update effectively space systems intended for earth remote sensing (ERS). A statement of the constrained update problem is discussed. An example is given to demonstrate effective updating process for the some ERS space system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Morozov H. I., Malozemov V. V. Mathematical model of biotechnical life support system and its components. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 25-28. Design problems are considered for biotechnical life support systems (BLSS) intended for implementation of various processes, which are parts of biological recycling of substances on board of manned spacecraft. Approaches are discussed to simulate biotechnical units of the BLSS as well as peculiarities of the appropriate models. Design results are discussed and analyzed for the mathematical models describing as the biotechnical units as the BLSS integrally. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tan W. ., Efremov A. V., Tiumentsev Y. V. An evaluation of aircraft handling qualities by means of neural network based prediction model for characteristics of pilot control actions. Aerospace MAI Journal, 2008, vol. 15, no 1, pp. 92-108. An approach is suggested to build a neural network based model, which allows to predict characteristics of pilot control actions. The model is developed using some data base containing experimental results. These results are obtained by means of test bench experiments involving human operator (pilot) for a set of different aircraft dynamical configurations. Frequency response of the neural network based model is compared with experimental results which was not utilized for a training of the network. The comparison demonstrates close fit for the theoretical and experimental data. The obtained model is used to derive selection criteria and handling qualities evaluation for manned aircraft. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makarenko A. V., Prilipov A. V., Samokhina K. E. Energy and mass properties of primary power supplies intended for autonomous actuators of mobile object control systems. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 3-12. A comparative analysis basing on integrated approach is carried out for various classes of primary power supplies intended for autonomous tracking actuators. These actuators are needed to solve control problems related to mobile objects. Recommendations are suggested to design the primary power supplies. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vdovin V. A., Kostin A. A. Using of corporate pension systems to prevent personnel drain as applies to aircraft Industry. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 95-101. An analysis is carried out to reveal advantage of some advanced approach to solve staff problems as applies to aircraft industry enterprises. This approach is based on corporate pension systems to enhance enterprise attractiveness for the staff. One of main problems is considered from this point of view namely how to prevent depreciation of pension reserves by means of efficiency increasing for asset management of non-state pension funds. An aggregative process scheme is analyzed to manage investment portfolio of the fund. A conceptual management scheme is suggested basing on rearrangement of portfolio assets for a financial tools level. A management algorithm is developed basing on modified oscillator for rate of change representation. An efficiency is demonstrated for the approach to manage investments of pension reserves. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobiev A. G. A mathematical model of thermal state for low-thrust liquid rocket engines. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 42-49. A mathematical model is suggested to describe a thermal state of low-thrust liquid rocket engines. Main attention is focused on such topics as physical meaning of model components, techniques used for analysis of engine properties, model capabilities to predict operational efficiency of combustion chamber in regard to its thermal mode, model capabilities to analyze engine efficiency for predefined propellant mixing scheme. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zenkova L. F., Kikot' N. V. A research and development experience in respect to front bearing of high-pressure compressor for a small-sized gas-turbine engine. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 63-67. Development history is described for the transmission of gas-turbine engine intended to a trainer airplane. Some versions of transmission layout analyzed during design process are discussed. Front bearing of high-pressure compressor is considered as an example. Results of design layout analysis are listed to present layout influence on the final design decision. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ighonin V. I., Chuchin V. N., Titov D. V. About locally modular arrangement of radiative-convective energy exchange for a part of industrial heat-and-power system. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 68-80. A locally modular arrangement of radiative-convective energy exchange is analyzed for a part of industrial heat-and-power system. Each part of the system is interpreted as a energy converter. The parts are described basing on functional relationships between system parameters and system entropy using the “flows and forces” concept. A model for integrated heat-and-power system can be constructed in the form of interconnected system parts. It is suggested to use three-level hierarchical representation of the system analyzed in the paper including micro-level, macro-level and meta-level. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karasiov V. N. Simulation of dynamical characteristics for complicated design scheme gas-turbine engines. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 30-35. Simulation dynamical models are discussed to analyze gas-turbine engines with complicated design layouts. These models are needed to study stability and control for airplanes with deflected thrust vector. Some examples are considered for dynamics of transition processes for integrated propulsion system based on double-flow turbojet engine with a separate fan. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karpenko E. M. Potential capabilities estimation for an industrial enterprise. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 102-107. An integrated technique is suggested to evaluate potential capabilities for an industrial enterprise. The technique is based on regression simulation and logical interpretation of simulation results. It is essentially needed to take into account the full set of potential elements, i.e. sources of their capabilities, to explain observed dynamics of main indexes describing enterprise activity effectiveness. It is needed to analyze as the capability sources such factors as traditional resources as well as non-resource indicators namely organizational structure of the enterprise, management style, enterprise staff knowledge, staff motivation level, market competition level. It is possible only with integrated taking into account all of the sources to evaluate correctly the potential capabilities of the enterprise. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozlov V. I. Some problems of modern electrodynamics. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 108-118. Electron dynamics is analyzed basing on some realization examples for plasmodynamic systems. This problem belongs to a separate area of electrodynamical studies. A general physical picture of electromagnetic field is considered that assumes existence of neutral electric field generated by material formations. Besides a potential nature of the electric field is supposed originating at the magnetic inductance variation in some spatial point. Problems of generalized electric field are discussed. Such field was introduced into electrodynamics by Maxwell as convenient concept to formalize electrodynamic links. Also concepts of absolute and relative in electrodynamics are considered. A possibility in principle is discussed to accomplish interplanetary missions without expendable mass consumption. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Larionov S. Y., Nechayev Y. N., Mokhov A. A. Investigations and analysis of “cold” blowing for a thrust module of high-frequency knocking combustion pulsejet engine. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 36-41. Tests are described and analyzed for a thrust module of knocking combustion pulsejet engine. This advanced engine was tested on a special experimental bench. An operation of the thrust module investigated with the bench is based on the Hartmann-Sprenger effect. High-frequency self-oscillation arise within the thrust module resonator shaped as a segment of sphere for some combinations of geometrical and gas-dynamical parameters of the resonator. Reasonable geometrical and gas-dynamical parameters of the thrust module are determined for forthcoming tests with ejector thrust enhancer for the non-steady pulsating stream case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leontiev M. K., Fomina O. N. An active stiffness control for bearing support of gas-turbine engine rotors. Structure and static analysis. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 57-62. Some measures are discussed to reduce a vibration level for high-speed gas-turbine engine rotors, especially in regard to transmissions of gas-turbine engine test benches. A bearing support design is suggested to allow stiffness control for the bearing. Numerical simulation results as well as static test data are considered for elastic parts of the bearing support. The bearing support described in the paper was manufactured and included in the transmission of the test bench intended to compressors of gas-turbine engines. Preliminary static and dynamical tests demonstrate functionality and operational efficiency of the bearing support design. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lobanov I. E., Myakochin A. S., Nizovitin A. A. Simulation of intensified heat-transfer for a turbulent flow within turbulator-equipped tubes by means of balance equation for turbulent pulsating energy. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 13-21. A theoretical model is suggested to describe intensified heat exchange for turbulent flows within channels equipped with turbulence promoter. The model is based on balance equation for turbulent pulsating energy derived for open surface valleys withrelatively small turbulence promoters. Heights of the promoters are comparable in this case with a thickness of a buffer area. Numerical simulation data are obtained for these conditions. These data correspond satisfactorily to existent experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlova N. V., Frolov M. D. Aircraft positioning with relief-metric extreme-correlation navigation system. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 85-88. A possibility is studied to use an extreme-correlation navigation system basing on relief-metric optoelectronic system for high-precision and robust aircraft positioning. A technique is suggested to evaluate aircraft position using relief information retrieved from optical characteristics of underlying terrain. Simulation data confirm sufficient reliability of the technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Obukhov V. A., Pokryshkin A. I., Popov G. A., Yashina N. V. Motion and orientation control for spacecraft on a high elliptic orbit. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 22-29. An electrical rocket propulsion system structure is proposed with rotating thrusters. The thrusters have star-like arrangement. They are located uniformly in the same plane while nominal directions of their thrusts cross the spacecraft inertia axis which is orthogonal to this plane. The suggested propulsion system structure allows to solve efficiently such problems as high elliptic orbit correction and spacecraft attitude control. The system ensures to enhance spacecraft energy efficiency by means of more comprehensive using of solar cell panel power and more saving consumption of fuel. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rakov D. L., Thorbeck J. . Active soundproofing system for noise reduction within aircraft passenger cabins. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 81-84. Active sound-suppression systems can be applied to reduce noise level inside aircraft passenger cabins as well as noise insulation for transport systems. An acoustic technique used in discussed investigations is named usually as 4S-technology (Steerable Sound Suppression System). This technique is based on acoustic effect arises under the influence of appropriate stress in porous material panels which results in surface and internal deformations of the panel. A relationship is revealed between noise suppression efficiency and degree of material deformation. One can change noise suppression capabilities of the panel generating various stresses in their material. This technique allows to shift panel noise suppression capability depending on the noise frequency. Some active, passive and adaptive noise suppression systems can be realized basing on the proposed approach.. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Talalayev A. A., Kolomentsev P. A. Technical facilities and techniques to test over-expanded nozzles for earth conditions. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 50-56. A gas-dynamic test bench is described as well as tools and techniques to study non-steady flows within nozzle assemblies of liquid-propellant rocket engines in earth conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyncherov K. T. An implementation of residue number scaling procedures. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 89-94. Some implementation versions are discussed for procedures to scale numbers represented in residue system code. These procedures are intended to use in digital signal processing. A high-speed algorithm is proposed as well as a structure for table arrangement of the scaling procedure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Salganik R. L., Mokhel A. N., Fedotov A. A. Contact problem of elasticity theory for semirestricted bodies with rough surfaces in the case of almost full contact between them. Aerospace MAI Journal, 2007, vol. 14, no 4, pp. 119-127. A contact problem of elasticity theory is considered for semirestricted bodies with rough surfaces in the case of almost full contact between them. Shearing interaction between contacting bodies is neglected. The plane strain case is analyzed as well as the spatial one. A numerical example is given to demonstrate how to solve the contact problem for the case of tyre on pavement with extended hole in it. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khomutova Y. V. Economic-based enterprise operation using cost management strategy. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 139-145. An ordinary method to evaluate enterprise activity based only on analysis of financial indices do not allow to react rapidly on changing market situations in hard competition conditions. A profit is considered traditionally as the main index describing an effectiveness of a business. Therefore some danger exists to pay this index too much attention. In this case other aspects of the enterprise activity including innovations, client policy, personnel qualification etc. cannot obtain proper attention. Such approach can results in great negative profit, in decreasing of the enterprise market segment and in a crash as the final result. According to a modern approach to business activity evaluation an enterprise cost must be the baseline index of enterprise effectiveness instead of the profit. A value of the approach is confirmed by extensive experience of the world economy. This experience demonstrates an importance of the enterprise cost as the evaluation index to enhance enterprise competitive ability. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khakhulin G. F., Novikov S. A., Posadsky A. I., Eskin V. I. Observations planning problem for movable sea objects as applies to space monitoring systems. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 125-130. A problem of observations planning is discussed as applies to automated space monitoring for movable sea objects. A formalized statement of the problem is suggested as well as reasonable techniques to solve it. The proposed approach is based on indirect stochastic programming methods and it allows to develop appropriate automated system to solve the space monitoring problem. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Troshin A. N., Nikulina E. N. Working capital management for enterprises with a long production cycle. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 159-168. Peculiarities for aircraft industry enterprises are considered influencing on basic indices which describe usage effectiveness for a working capital. A structure and relations are revealed for operational, production and financial cycles of the enterprise. A management mechanism is suggested as applies to a financing of current asset Characteristics of main funding sources are analyzed for the short-term financing.s according to some selected strategy. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tolstikov L. A. An analysis of inertial forces effect on fluid within rotating blade wheel of impeller machine. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 35-40. Deficiencies are revealed and discussed in regard to conventional techniques used in the impeller machines theory to analyze forces acting on a fluid in the rotor. A detailed analysis is carried out for absolute and relative accelerations. It is shown that «circulatory» forces in a relative motion as well as in a absolute motion are caused by persistence proper angular acceleration in the absolute motion as well as by Coriolis acceleration originate from angular velocity ty of the fluid. Total forces specifying rotor moments are inertia forces caused by of absolute motion and radial velocity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Talalayev A. A. Thrust enhancing for nozzle assembly of a liquid-propellant rocket engine within dense atmosphere layers using atmospheric air. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 29-34. An improvement of a structure is suggested for automatic-adjusted nozzle assembly of a liquid-propellant rocket engine intended as a cruise one for the first stage of a launch vehicle. The improvement allows to enhance operational properties of the engine within dense atmosphere layers using atmospheric air, i.e. during initial path segments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ryazanov A. V. A structure of advanced self-testing digital frequency synthesizers built in integrated-circuit form. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 131-138. A generalized structure scheme design is considered for an advanced large-scale integration circuit implementing digital frequency synthesizer. The synthesizer includes self-testing tools based on the signature analysis. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pilishkin V. N. Constraint-based controller synthesis in regard to a motion within neighbourhood of a specified set. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 117-124. An important application problem class is considered associated with taking into account constraints which are imposed on a motion of some dynamic system. There are various factors needed to consider including a possibility to provide solvability of the synthesis problem as a result of allowable deformations for some of the constraints; a possibility to specify non-rigid constraints; an insensitivity (robustness) of the motion to disturbances. An approach is suggested which allows to solve these problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leferov A. A., Kul'chikhin V. G. Maintenance-time diagnostics of fuel supply apparatus for diesel engines. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 52-58. Some general approach is discussed to implement vibration-based maintenance-time diagnostics for fuel supply apparatus of diesel engines including aviation ones. Main feature of the approach consists in providing a maintenance monitoring of the fuel supply apparatus without its removing from the engine. Appropriate techniques are developed to solve this problem including procedures for vibration-based diagnostics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Levsky M. V. Optimization of reorientation maneuvers for a spacecraft. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 104-111. A control problem for a spatial maneuver is described and solved to change a spacecraft orientation during minimum time interval. An analytical solution is found for the problem under angular momentum constraint. Necessary optimality conditions are derived based on quaternion technique. A complete solution of the reorientation problem is obtained in closed form for a case of dynamically symmetric spacecraft. Results of mathematical modeling are given to demonstrate a practical possibility of on-board implementation for the proposed technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M. A physical model for a hydrodynamically nonsteady turbulent flow. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 48-51. An analysis is carried out to reveal an influence of nonisothermality and hydrodynamic nonstationarity of a flow on generation and propagation of turbulence. A physical model is suggested for a hydrodynamically nonsteady turbulent flow. The model is based on experimental data obtained in previous research intended to study of structure for the gas flow within some channel. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Korshakovsky S. I., Krasnenkov M. А., Markov A. A., Subbotin V. Y. Measurement of airspeed for a flying vehicle. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 10-16. A new technique is suggested to measure airspeed for aircraft. This technique is based on generation of two ltrasonic waves traveling towards each other and measuring of mechanical pressure within acoustic field. The mechanical pressure is transformed into electric signals by using piezoelectric effect. These signals specify time intervals for propagation of acoustic waves in defined directions. A value of the airspeed is computed using the measurement data obtained. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Letova T. А., Kondakov V. K. Internet textbooks generation for mathematical disciplines based on the TBBuilder2 software environment. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 112-116. TBBuilder 2 is a special-purpose software environment used by the Mathematical Cybernetics Department at the MAI to prepare Internet-textbooks for applied mathematics courses. This software environment is intended mainly for open education support. The environment consists of various software modules including editing and automation tools. It becomes easier for author to do actions related to a filling of information bases with didactic data needed for the Internet-textbooks. Techniques and procedures are discussed as applies to a development of some Internet- textbooks by a lecturer using the TBBuilder 2. Techniques of self-education for a trainee are described too by means of the Intenet-textbooks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozlov V. I. An electron dynamics within discharge of a stationary plasma engine. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 75-94. A dynamics of electrons is investigated within discharge of a stationary plasma engine taking into account their transfer across the magnetic field from a cathode region to anode. Obtained results show that the transfer is caused at least by three mechanisms. The first of them is a negative gradient of the field acting after the exhaust engine exit, the second is a positive gradient of electron pressure acting in the anode region of the discharge. The third cause is an electron friction against the walls of a discharge chamber. It is determined by the electric field influence. When the transfer occurs some plasma oscillations are excited in microwave band as well as in high and low frequency bands. The results of the modeling are compared with corresponding experimental data and fit them satisfactorily. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sukharev O. S., Shmanev S. V., Kur'yanov A. M. Synergetic approach to manage for investments. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 153-158. Conventional economic models intended to investment decision-making are compared with theory and practice needs. Some inconsistencies are revealed in regard to a real practice of investment management. An approach is suggested to overcome these difficulties. The approach is based on synergetic control concepts. Main features of this approach are described and analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karakulin E. A. An analytical technique to constrain applicability of simplified mathematical models for unsteady flows of incompressible fluids within pipelines with rigid walls intended for computation of dynamic processes in pipeline systems. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 64-74. A simple and precise analytical technique is suggested to constrain applicability of simplified mathematical models for unsteady flows of incompressible fluids within pipelines with rigid walls intended for computation of dynamic processes in various real-world pipeline systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinnikov V. V., Kadyshev V. V., Reviznikov D. L. Using of the ghost-cell immersed boundary method together with multigrid method to solve problems for viscous incompressible fluid flows. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 95-103. An application of the ghost-cell immersed boundary is discussed to model viscous incompressible fluid flows for regions with complicated boundaries. An approach is suggested to solve problems arising in regard to cooperative using of the submerged bound technique and the multigrid technique to solve Navier-Stokes equations on non-staggered Cartesian grids. A laminar flow within a diffuser are examines as an example. A close fit is demonstrated between results of the example and corresponding reference data as well as high efficiency of the approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kolomentsev A. I., Zakharov S. A., Yakutin A. V. A mathematical model for computation of gas mixture thermophysical properties. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 41-47. A mathematical model is suggested to compute gas mixture thermophysical properties. This model is intended to support numerical simulation of work processes in liquid-propellant rocket micro-engines. The model structural and algorithmic features allow to adapt its using in regard to various kinds of gas mixtures. The model enable a computation of such properties of the gas mixture and its components as density, heat capacity, dynamical viscosity and heat conductivity based on approximation equations with respect to pressure and temperature values. A software package is developed to implement the suggested model. Results of numerical experiments obtained by using the package are provided and discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhdanov V. I. Cavitational oscillations in two-stage injectors. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 59-63. Research results are presented to study two-stage injectors for operational conditions with cavitational oscillations. It is shown that these oscillations are similar in terms of their physical nature to stalling cavitational oscillations within divergent cone channels for jet fluid flows. Using of self-oscillating cavitational flows in the centrifugal injectors can provide significant improvement of dispensing quality for fluids. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grumondz V. T., Miagkov K. G., Stepanova V. V. An application of the bubble cavitation for a treatment of hydrocarbon liquids. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 146-152. A possibility is discussed to use physical-chemical effects arising through bubble cavitation to solve an important ecological problem. The problem consists in transformation of petroleum tailings remaining as a result of petrochemical processing. A physical-chemical model is made for processes, which occur in oil in case of bubble cavitation arising in it. An estimation is obtained for a mass flow of the stuff. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko A. N., Deniskin Y. I., Medenkov A. A., Sorokin A. E. Export of aerospace education. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 3-9. A comparative analysis basing on integrated approach is carried out for various classes of autonomous tracking actuators intended to control problems solving for mobile objects. The analysis is performed using a set of energy and mass indices. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko A. N., Makarenko A. V., Prilipov A. V., Sorokin A. E. Comparative analysis of control system autonomous actuators for mobile objects based on energy and mass indices. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 17-24. A comparative analysis basing on integrated approach is carried out for various classes of autonomous tracking actuators intended to control problems solving for mobile objects. The analysis is performed using a set of energy and mass indices. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Babkin A. N. An anthropocentric concept of take off and landing system for a Martian expedition. Aerospace MAI Journal, 2007, vol. 14, no 3, pp. 25-28. Functional requirements are suggested for component parts of take off and landing system intended to a Martian expedition. Corresponding research to make these requirements is carried out basing on preliminary scripts and designs for an interplanetary expedition to land on the Martian surface. One of the main goals of the research consists in providing of efficient extravehicular activity of cosmonauts after a landing on the planet surface. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bardin B. S., Checkin A. M. About orbital stability of plane rotations for a plate satellite travelling in a circular orbit. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 23-36. An angular satellite motion is considered as applies to circular orbit within a central Newtonian field of gravitation. The satellite is regarded as a rigid body with a plate-like mass distribution geometry. A nonlinear analysis is performed for orbital stability of satellite plane rotations. The plane of the plate during these rotations | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Thien Z. D. An implementation and experimental investigation of nonlinear radiolocation aids. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 67-73. Performance characteristics are described for some nonlinear series-produced radars. An experimental investigation was carried out to reveal key features of nonlinear radiolocation. The investigation are based on capabilities of the HP-900 EM nonlinear junction detector to measure secondary fields. A metrological support of nonlinear radar measurement is discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Belousov V. E., Salkova N. E. About a procedure to choose critical technologies and priority ways for scientific and technological advance. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 101-105. There exist a set of normative and legal documents to support reasonable choice and implementation of research priorities and critical technologies. These documents specify an interaction of the state with research institutions and private sector of economy to generate the list of priorities and technologies mentioned above. Also the documents provide a resource concentration as applies to selected development ways for the purpose of steady social and economic progress of the country. A procedure to choose critical technologies and priority ways for scientific and technological advance is suggested based on these factors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Efremov A. V., Ogloblin A. V., Tan W. ., Tiumentsev Y. V. A neural network model of pilot control behavior. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 53-66. Mathematical models of pilot control behavior characteristics are very important for manual control problems in regard to closed aircraft-pilot systems. Conventional models of such nature suffer from some drawbacks which make difficult to solve application problems mentioned above. An artificial neural network based model of pilot control behavior is suggested to overcome these drawbacks. The model is derived from experimental data obtained during pilot-aided tests using a special workstation meant for manual control studies. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bordakov V. N., Afanasiev V. V., Orekhov V. A., Pilchenko V. A. Development of a pilot plant for alcaline hydrolysis of lewisite. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 115-123. Development of a pilot ejector chemical reactor is discussed to study experimentally process-dependent parameters for alcaline hydrolysis of lewisite. The reactor ensures environmental safety of the hydrolysis process. Main results of the study are described and analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vikulov A. G. A thickness of surface film estimation by means of electrical measurements within metal-to-metal contact. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 47-52. An experimental technique is offered to estimate a thickness of film-on-metal (surface films). The technique is based on the Kholms theory as well as on some procedure to compute the real contact surface according to surface properties and mechanical characteristics of the contact. A quantitative analysis is carried out to evaluate an influence of average contact temperature and surface film thickness on emission and electron tunneling through contact area. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galiullin I. A., Kondratieva L. A. A spatial spiral motion of underwater vehicles. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 41-46. A dynamic possibility is proved to obtain some kind of spatial spiral motion for underwater vehicles. The center of the vehicle corresponding with a point of application for its buoyancy force moves along some helical curve. The vehicle is represented as a dynamically symmetric solid body and allowance is made to shift its center of mass relative to its axis of symmetry. Conditions are investigated which impose constraints on parameters of the body as well as on its angular motion. The problem solved in the paper is getting significance to analyze a motion of two-medium capable vehicles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanova E. V. Transformation peculiarities for the market of capitals in Russia. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 106-110. Some problems are discussed with regards to features of transition period for the Russian economics especially for its segment which relates to a reproduction of capital resources. Qualitative regularities are analyzed to describe a primary capital accumulation stage as well as some quantitative parameters defining self- organization processes for the market of capitals in Russia. The necessity of the analysis is grounded depending on principles of evolutionary analysis. This approach allows to evaluate current events basing on studies of backgrounds | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Inozemtseva E. A. Competitive-based formation and execution of research orders in scientific institutions. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 94-100. One of the basic financing sources for scientific institutions in modern economy is getting a government work to carry out research investigations. According to the legislation of the Russian Federation a placement of order is carried out on a competitive basis. An information-procedural model suggested in this article shows clearly a process of placement and execution for the research government work. The model describes not only basic stages of the process but also titles of providing documents. An analytical table is presented also which allows to analyze a compliance with project conditions and customer requirements for the scientific institution and to evaluate competitors. Such kind of analysis makesit possible to estimate institution chance of success as well as to reveal shortcomings and to manage necessary innovation transformations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kotelnikov M. V., Garanin S. B. About applicability of the Courant-Friedrichs-Levy condition for problems related to edge plasma electrodynamics. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 37-40. An influence of a time step value on stability and convergence is analyzed for solutions of numerical simulation problems associated with plasma flow around a body. It has been established that the Courant- Friedrichs-Levy condition for the time step is too strict as applies to the problem mentioned above. A possibility is proved to multiply up many times the time step value providing considerable saving of computer resources | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kochneva L. . About nature of noosphere and development of consciousness. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 124-131. Ecology is discussed as some world-view stimulating adequate relationship between humans and the nature. A reflective consciousness is emphasized which allows to begin a process of professional self-consciousness development for university students within their academic activity. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mkrtchyan G. A. Managerial controlling: Modern theoretical concepts and practice in aerospace economics. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 86-93. Some modern theoretical concepts and methodology are considered for controlling as applies to its real operation. A system nature of the controlling is revealed also its position among other managerial disciplines. A conceptual «singularity» of the controlling is demonstrated and at the same time its relations with main company jobs and with these jobs realization programs are described. Realization stages are discussed for a controlling system. A role of feedforward and feedback concepts as well as real-time information in controlling system is analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Palkina M. V. Stimulation and support of investment activities for regional enterprises: present-day situation and progress trends as exemplifies by the Kirov Region experience. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 74-78. Present-day situation and efficiency of the state support for investment activities of economic entities are analyzed. The analysis is carried out basing on the experience of the Kirov Region. The investment activity support by the regional authority is discussed in regard to data for the years 2003 — 2005. Ways of development for state investment activity encouragement and stimulation are suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Razoumnova L. L. A strong growth problem for the Russian economics taking into consideration an uncertainty of a current situation for the world oil market. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 79-85. Russian economics depends appreciably on external environment fluctuations. Main factor of such instability of the environment consists in sharp and unpredictable variations of world prices on goods exported by the Russia especially oil prices. Problems caused by this dependence attract considerable public attention and arouse discussions about using of superprofits realized by means of the oil export and accumulated in the Stabilization Fund. A foundation of necessity is suggested to generate some clear economic strategy which will ensure a strong long-term growth of the Russia economics. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sergunina T. E. Methodological regulations concerning planning and forecasting of budget revenues for airlines. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 111-114. A problem of incomings planning is discussed as applies to passenger airlines. A structure of budget is analyzed for the airlines. Such parts of the budget are separated and compared as incomings budget caused by air transportation, selling budget and inpayments budget. A cycle process to manage airline incomings is considered in more details as well as the problem of planning and forecasting budget revenues for airlines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenikhin S. A., Sysoyev D. V., Tikhonov V. B. Using range of an external magnetic field in the magnetoplasma thruster. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 3-8. A magnetoplasma thrusters using lithium as a working substance are studied in the paper. There are typically two kinds of the magnetoplasma thrusters. One of them is a self-field thruster with magnetic field generated by discharging current and the other ones is an impressed-field thruster with external magnetic field generated by some outer solenoid. As the discharging current and respective power increase a contribution of the external magnetic field to the power decreases.Therefore it is unreasonablу to expend the power on generation of the field fr om some value of the current. An approach is suggested enabling to estimate the upper lim it for the power and current bounding the rational usage area for the external magnetic field. In the case of the steady-state magnetoplasma lithium-fed thruster this boundary takes on a value approximately 300-350 kW. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
An improvement of thermal-hydraulic efficiency of shaped tubes. Aerospace MAI Journal, 2007, vol. 14, no 2, pp. 9-22. A technique and results are presented for experimental research of heat transfer and hydraulic resistance for water flows within shaped tubes. The tubes have a ring diaphragm knurl with various shapes of turbulence stimulators. Some new generalizing relationships are suggested to intensify the heat transfer and to compute an increasing of the hydraulic resistance for the water flows depending on geometric characteristics of the shaped tubes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Baranov N. A., Nesterov V. A., Poliansky V. V. An influence of surface damages on aerodynamic characteristics of a flying vehicle. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 13-19. Nonlinear aerodynamic characteristics for damaged flying vehicle are considered based on numerical analysis results. The analysis is performed in regard to symmetrical damages of lifting and control surfaces of the vehicle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidov A. S., Kashelkin V. V. An energy dissipation for oscillating systems consist of thin-walled unit with a point loading. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 39-42. Techniques are considered to study some modal characteristics including logarithmic decrement and natural frequency for beams and silphons with a point loading. The study is based on experimental results obtained by the authors as well as on data extracted from other publications. The beams studied were made of stainless steel, structural steel, duraluminium or magnalium. It is shown that a residual life for oscillating systems with a point loading can be expressed through their modal characteristics. Some examples are given which allow to confirm these conclusions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kuranov A. L., Korabelnikov A. V., Ryzhikov S. S. A numerical investigation of thermochemical reactor as a part of heat-protection system for hypersonic vehicle. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 43-49. A flat thermochemical reactor is studied numerically as a part of heat-protection system for a hypersonic flying vehicle. The reactor is intended to absorb thermal flows and to generate hydrogenous mixture. Simulations are carried out under the assumption of narrow channel for laminar and turbulent flow regimes. A basic chemistry reaction used in the reactor is methane steamed reforming. It is shown that the flat thermochemical reactor can be used effectively to cool high-beat surfaces as well as to convert an original hydrocarbon fuel into some more high-calorie fuel. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Osavchouk N. A., Yudin V. N. An reliability evaluation technique for detector radar functioning under clutter environment. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 82-87. A technique is proposed to evaluate an effectiveness of radar intended to aerial target detection in various jamming conditions. The technique is based on some probability measures. Analytical estimations of radar noise immunity are derived using Markovian processes as applies to locking-in for the detected aerial target. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plokhikh A. P., Vazhenin N. A., Volkovsky A. S. An analysis of electrojet engine self-radiation influence on characteristics of command radio link for deep-space communication systems. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 55-70. A numerical analysis is carried out to evaluate self-radiation influence of modern and advanced electric propulsions on characteristics of command radio link for deep-space communication systems. The characteristics considered include maximum range and maximum information rate for the radio link. Recommendations are proposed to decrease negative consequences of this influence. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Skouratov A. K. Statistical monitoring and analysis for telecommunications networks. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 71-81. A study is carried out to analyze state-of-the-art and trends for Russian telecommunication networks on national and regional scales. Some basic measures are revealed providing statistical monitoring and analysis for the networks. Various techniques are used to solve the analysis problems including regression analysis, discriminant analysis, claster analysis, artificial neural networks, time series analysis. The proposed techniques are tested solving several real-world problems related to operation analysis for some telecommunication networks. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Starkova M. M. Financial and economic justification indices for external management plans. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 88-94. A problem of economic justification is considered as applies to external management plans in developing market economy conditions. Many of enterprises meet with serious difficulties under such conditions. This situation is aggravated for lack of theoretical foundations to solve the justification problem. An effort is attempted to create some approaches providing development of optimal strategies for anti-crisis enterprise management. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenikhin S. A., Sysoyev D. V., Tikhonov V. B. Experimental investigation of barium additive influence on functioning of magnetoplasma thrusters. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 20-29. A magnetoplasma thrusters using lithium working substance are studied to reveal an influence of barium additive on their performances. The influence are examined in regard to integral thruster parameters (thrust, efficiency and voltage-current characteristic) as well as local ones (e.g., a temperature of active zone for the cathode). The barium additive usage provides decreasing of the cathode active zone temperature down to 400 K preserving integral thruster performances. According to obtained estimations this temperature decreasing allows to alleviate resource limitations caused with thermal evaporation of the cathode. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Timofeyev O. A., Spirin G. G., Vasilevsky D. V. A heat conductivity analysis technique for dielectric fluids within microvolumes . Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 50-54. A technique is proposed to analyse heat conductivity for dielectric fluids within microvolumes. The technique is based on a pulse heating of fast-response resistive elements contacting with the fluid studied. Measurement results are classified using short-term deviations for some irregular thermal conditions. This approach is tested as applies to a heat conductivity problem for 5 different organic fluids | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tkachenko D. P. Experimental investigations of NOx emission for combined frontal devices. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 30-38. An experimental investigation is carried out to study burning processes within a complex combined frontal devices. The devices realize two distinguished combustion principles namely diffusive and homogeneous ones. Special emphasis is paid to NO and NO2 emission for studied frontal devices. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tarasov E. V., Yupha D. I. Decision making techniques under multiple-factor uncertainty for design analysis of flying vehicle. Aerospace MAI Journal, 2007, vol. 14, no 1, pp. 3-12. A necessity is demonstrated to take into consideration several uncertainty factors during a process of design decision making. An approach is introduced to the discussion to estimate multiple-factor uncertainty. Some technique is derived for design decision making based on the approach. A concept is offered to build some algorithmic and software system supporting decision making under multiple-factor uncertainty for design analysis. An example of realization for the system demonstrates a practical performability of the approach discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Avkhimovich B. M. An accuracy of algorithms for generation of heat-loaded structures which are equivalent with respect to non-stationary temperature fields. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 21-25. Some computational experiments are carried out to study accuracy of algorithms generating equivalent variants for heat-loaded structures. These experiments are based on elementary models such as a plate, a cylinder, a sphere for one-dimensional, two-dimensional and three-dimensional non-stationary thermal conductivity problems respectively. The obtained results give an estimation of accuracy and efficiency of mathematical tools used for the model generation based on the temperature equivalence principle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Firsanov V. V. A numerical model of dynamical and deflected mades for separation systems of aircraft guided missiles. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 3-20. Mathematical models are described for computation of vibro-dynamical and deflected modes as well as separation parameters for a motion of guided missiles launched or catapulted by means of appropriate devices. Numerical results are given for dynamics of separation systems implemented as rail-type launchers with straight or curvilinear ways. Numerical analysis is also carried out to reveal an influence of elasticity and mass characteristics as well as structural nonlinearities for a system which consists of guided missile, launcher and aircraft wing onto separation parameters and strength of the separation system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Talalayev A. A. A simulation of high-altitude operations for jet nozzle tests on a gas dynamics differential plant. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 26-30. An altitude chamber is applied usually to provide separation-free gas flow during tests of high-altitude supersonic nozzles. The chamber needed for the tests is rather cumbersome and expensive plant. A supersonic diffuser is suggested to use instead of the altitude chamber. The diffuser is intended to isolate gas jet flowing out of the nozzle from environment along some distance. An analysis is carried out to reveal parameters of the diffuser suitable to various tested nozzles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenov V. V., Volkov V. A., Kvon Min Chan .. .. An exact solution for linearized problem of supersonic airflow over a flat relief. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 36-40. Theoretical results for shock-wave drag value estimation taking into consideration a surface relief exist only for some simple relief forms. Nearly all of them are obtained by solving of a boundary problem for a linear second-order partial differential equation derived by Blokhintsev. This boundary problem is solved in the paper analytically for a case of two-dimensional supersonic flow near reliefed surface. An arbitrary form of the relief is suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plokhikh A. P. An experimental investigation of backscattering diagrams for plasma formations generated with electro-jet engines . Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 79-89. Issues of electromagnetic wave interaction with artificial plasma formations generated by electric propulsions are discussed in this paper. A general procedure for the test study of such plasma formation scattering properties under ground conditions is considered. Mechanisms for the influence of plasma formation parameters on its backscattering pattern are discussed by means of examples derived from the tests. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pankova L. V. Innovation processes in the USA aerospace industry: Most important changes. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 115-120. An aerospace industry is one of fast developing branches of a manufacturing industry in industrialized Western countries. A competitive ability for the industry depends immediately from innovations searched and introduced constantly. Most important changes are described and discussed for a set of factors influencing on innovation activity in the USA aerospace industry. Systematization and generalization of the changes are needed to reveal possibilities for intensification of innovation processes in the Russian aerospace industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Myakochin A. S. Development of a technique for evaluation and regulation of economical return from using of material and land properties which are at disposal of industrial enterprises. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 128-134. A problem of effective using for material and land properties which are at disposal of Moscow industrial enterprises is discussed. A technique is developed to evaluate an economical return from utilization of the properties. The technique is implemented as a software product to allow automation of the analysis required. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kotov Y. V. Flexible dielectric wave guides with small losses for multi-element antenna arrays. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 90-105. Design alternatives are suggested for flexible dielectric wave guides with small losses meant for multi-element antenna arrays. A numerical technique is developed to compute eigenvalues and fields for dielectric paths. Numerical investigation results are described allowing to evaluate dispersion features of the dielectric paths with various cross-section forms. An evaluation criterion is offered for the investigation data to extract «false» decisions obtained as a result of a replacement of the complex Green function with its real part. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kozlov V. I. An investigation of electron dynamics after output section of flash chamber for a stationary plasma engine. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 55-66. An investigation is carried out to study an electron dynamics in a decaying magnetic field after the exit plane of a stationary plasma thruster (SPT). Processes of electron transfer from the SPT near-cathode area to its discharge chamber are taken into consideration. According to results obtained «abnormal» electron transfer after the SPT exit plane is stipulated with interaction between a current of electron gradient drift and the magnetic field. This interaction has the Hall effect nature. Such transfer is unstable and leads to an excitation of high- frequency (~200 MHz) and low-frequency (~20 kHz) drift oscillations of the plasma. The results obtained are compared with test data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isaev Y. O. Business strategy and business planning for a bank. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 121-127. A banking strategy concept is analyzed involving strategic analysis techniques and their applications to business planning for a bank. Significance and meaning of the Mission and the Vision concepts are investigated in regard to the bank. The results obtained are based on SWOT (Strengths, Weaknesses, Opportunities, Threats) approach. Strategic alternative and recommendations are formulated to guide future development of the bank. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zhdanov V. I. A computation of parameters for two-stage injectors operating in a self-oscillation regime. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 31-35. A possibility is demonstrated to appear oscillations of fluid discharge and pressure within a tube feeding the large-discharge stage of a two-stage injector. The oscillations can also appear in conventional fluid centrifugal burner provided that twisting chamber of the injector is connected with the feeding tube. Experimental results are described to estimate pressure values for the injectors discussed. A computation technique is offered to evaluate two-stage injector geometrical and operational parameters for throttling and bypassing modes of functioning. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishanina T. V., Savoushkina A. Y. A computation of oscillations for large aspect ratio wings with engines installed on elastic pylons. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 48-54. Bending-torsional oscillations for large aspect ratio wings are considered taking into account transversal shears, shell angle of taper as well as engines installed on elastic pylons. A boundary problem for harmonic oscillations described with ordinary differential equations and boundary conditions caused by concentrated reactions from the elastic pylons with attached engines is solved numerically reducing it to the Cauchy initial value problem for ordinary differential equations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Brusov V. S., Tiumentsev Y. V. A synthesis of optimal neurocontroller ensemble for multiple-regime aircraft. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 67-78. Application possibilities are discussed for artificial neural networks to solve problems associated with aircraft motion control. Aircraft are treated as multiple-regime dynamical systems (MDS). It is suggested to use neural controller ensemble (NCE) for a case of essentially multiple-regime systems. According to this approach we begin with a synthesis of a model for controlled MDS, then we build a neural controller for a single-regime system and generate an index to evaluate efficiency of the controller. After that a concept of the NCE is introduced based on the results for the single-regime system controller as well as an efficiency index is derived for the MDS case. Three essential optimization problems are formulated which are typical for the NCE assigned for MDS. Main features of the considered approach are illustrated via solving of a control problem for a simple MDS. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Biruykov V. I. Operation features of multiple-mode propulsion plants with thermal hydrazine dissolution. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 41-47. A burning instability is one of essential and difficult problems for liquid-propellant engines preventing to implement high-efficiency propulsion plants meant for various applications. This problem is especially difficult for a case of multiple-mode propulsion plant because of non-stationary nature of its characteristics. A technique is offered and discussed to analyze operation process for a propulsion plant with controlled thrust by means of detailed description for processes in combustion chambers as applies to propulsion plants with thermal hydrazine dissolution. The analysis is carried out mainly for low-frequency instability case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Balashov V. V., Smirnov A. V. A structured econometric model of demand for air passenger transportation. Aerospace MAI Journal, 2006, vol. 13, no 2, pp. 106-114. A structured econometric model is suggested to evaluate a demand for passenger air operations. A technique is developed to compute a «threshold level» for incomings. Population is permitted to use air transportation systems after the level is reached. The technique is based on international econometric comparisons and incomings distribution structure for 20-percent population groups. An algorithm is developed to estimate a number of air passengers paid for a flight out of their own pocket. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Borodin A. I. An approach to generation of informational background for ecological and economical decision making. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 89-108. An information background is needed for decision making with the purpose of effective ecological and economical management. It is proposed to form a special ecological account subsystem within traditional general purpose accounting system as well as to introduce suitable procedures into practice of accounting policy. A necessity of these actions follows from relationships between business accounts, charges, risks, liabilities and ecological policy of enterprises. A set of recommendations are developed to improve registration, evaluation and accounting of ecological costs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Burdina A. A. Methodological aspects of managerial decision making related to price formation and optimization of product assortment. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 116-124. A price formation technique is proposed, which contains an oscillating constituent to take into account amplitude oscillations for prices of competitors with regard to some basic trend. The technique is appropriate for using with the purpose of product yield finding to support more effective operation for a corresponding integrated automated informational and analytical management systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Veretennikov V. G., Sinitsyn V. A. About application of the virtual displacements principle. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 31-35. An application of the virtual displacements principle is considered in regard to three main cases, including systems with wall constraints, systems described with equation of motion possessing non-unique solutions, systems with discontinuous forces in equilibrium condition. Various equilibrium examples are presented for some special cases including non-regular point of constraint surface as well as non-analytical dependence force of position. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubenets S. A., Zinchuk A. A., Lipaev A. A. A cleaning of a soil contaminated with oil products. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 18-24. Some problems are considered in regard to cleaning of sizeable soil bulks contaminated with hydrocarbon fuel. A technique offered is based on sublimation of oil products followed with their condensation. The technique based on two-stage heat impact scheme not only restores the soil but also allows to extract partly the oil products. Preliminary analysis results are presented to select possible design features and parameters for main parts of a cleaning plant. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krug P. G. Reliability estimation for mathematical methods and software used in virtual simulators of motor-truck scales as applies to transport aircraft. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 64-70. Development problems are analyzed for mathematical methods and software used in virtual simulators intended for motor-truck scales testing and maintenance. An evaluation is offered for reliability of the scales software used to stow loaded motor-trucks inside cargo aircraft taking into account requirement to keep aircraft center of gravity within some prescribed range of values. It is demonstrated the technique offered can be applied to control the motor-truck scales and assures a high level of measurement precision. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M., Tsar'kov A. N., Bugakov I. A., Gerashchenko A. N., Ryazanskii V. V., Yurov N. N., Goncharenko V. I. Integration of civil and military aducation as an effective way to enhance a unity of national scientific and educational area. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 3-8. Integration of civil and military education is an important way now to enhance education quality for civil and military specialists. The integration problem must be solved taking into consideration a necessity of a united national scientific and educational area. At the same time consideration should be given to needs of the state and regional labor markets as well as difficulties with financing of higher school. Institutions of the higher school are needed to optimize their resources based on modern information and communication society peculiarities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Panagushin V. P., Raikova Y. M., Kuznetsov V. S. A set of indicators development for evaluation and stimulation of economical return for a city, region or territory budget based on usage of land and material properties which are at industrial organizations disposal. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 109-115. A development problem is considered for a set of indicators intended to estimate and stimulate an economical return for a city, region or territory budget; the return is caused with usage of material and land property by industrial organizations. A developed technique is based on calculation of an integrated indicator combining values of some partial indicators. The technique allows to use more expediently land resources leased to industrial organizations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plokhikh A. P. Experimental investigation of aperture deflector characteristics in the presence of plasma formations in a mouth. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 71-82. Typical aperture radar deflectors are investigated experimentally to find their characteristics in the presence of plasma formations in a mouth. An influence of plasma parameters on a directional diagram of the deflector is analyzed for the plasma located in the deflector mouth. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pykhalov A. A., Ravikovich Y. A. An analysis of combined turbo-machine rotor to reveal its structural disfunction. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 25-30. There is a manufacturing joint between turbine disk and shaft in a rotor of gas-turbine engine needed to assure structural modularity requirements. The join changes physical properties of the combined rotor in comparison with a solid one. It concerns especially stiffness of the rotor. A technique is proposed based on the numerical finite-element method to analyze such properties and characteristics of the combined rotor as its deflected mode, amplitude frequency response, contact thermal conductivity. A special attention is paid to reveal structural disfunctions of the rotor. The technique enables a constructor to simulate a dynamic behavior of the rotor taking into consideration elasto-plastic material properties as well as contact thermal conductivity of conjugation surfaces. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoilenko M. V. Image-based identification of observed aerodynamical object. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 83-88. An identification problem is solved for some observed aerodynamical object based on its lengthy image. Collections of reference object images observed for various angles are used as an a priori information for comparison purposes. A technique is offered to choose reference images from the collections. The technique allows to pick out some reference image with the same angle as observed one. A using of binary images is proved to identify observed object. It is substantiated also an utilization of decision making algorithm based on maximum coincidence of identified and reference image shapes. A special index is proposed to evaluate the coincidence for image shapes. A considerable advantage is shown for this index in comparison with frequently used correlation one. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sizikov E. V. An effective context search and text indexing based on compressed inverted-signature file and approximate union key. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 56-63. New data structures as well as text indexing algorithm for appropriate context search in large text collections is suggested in the paper. Efficient support of approximate string matching search in texts (string matching with k-errors) is the main feature of the algorithm. The proposed algorithm is characterized by high search speed for requests with complex regular expressions which contains large amount of atomic patterns. A new index file type called compressed inverted-signature file is introduced for compact storage of indexing data. A new dynamic structure named approximate union key is offered to solve an approximate string matching task for index vocabulary. The compressed inverted-signature file with approximate union key can be used as a kernel of next generation text retrieval systems with flexible query language to allow advanced text search. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Talalayev A. A. An improvement of techniques and tools for information acquisition during investigation of non-steady gas flows within nozzles by means of gas-dynamic differential plant . Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 13-17. An improved technique is proposed to carry out experimental investigations by means of gas-dynamic differential plant. These experiments are intended for comparative studies of several high-altitude nozzles, detailed investigation of non-steady gas flows within nozzles, detection and estimation of factors affecting on a thrust of jet engine nozzles. The kernel of the technique consists in some mediate comparison of two tested nozzles with the reference compensating nozzle. An experimental error is evaluated for various operation conditions of the tested nozzles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tsipenko A. V. Feature investigations for concentrated gas-drop flow within a nozzle of a pilot plant by means of numerical and full-scale experiments . Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 45-55. A numerical simulation is carried out for a two-dimensional gas-drop nozzle flow with a significant portion of liquid fraction in it. This sort of the flow occurs in a knapsack fire fighting equipment developed at the MAI. A model used for simulation takes into consideration a presence of a film, collisions and aerodynamic fragmentation for drops. A multifluid approach and particle-in-cell method are realized in the model. It is proved numerically and experimentally for high concentrated gas-drop flow that the nozzle operates like a peculiar «mill» breaking drops. Other obtained results include: the film is very stable for subsonic fluid velocities; it is exist increased fluid content and gas pressure near nozzle exit section; a zone exists near a wall within expanded part of the nozzle with an inclusion volume fraction which is significantly lower than average value for the flow. The results obtained demonstrate suitability and usefulness of the model to solve problems concerned with numerical investigation and prediction of gas-drop flows. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Romasenko E. N., Beliayev E. N., Kanalin Y. I., Chervackov V. V., Beliayev D. E. Turbining of screw centrifugal pumps for liquid-propellant rocket engines. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 9-12. An analysis and generalization are carried out for properties of screw centrifugal pumps intended for liquid-propellant rocket engines in regard to turbining modes. This paper is keeping on the sequence of previous publications accomplished jointly by researchers from MAI and Energomash Corporation. Experimental data for the screw centrifugal pumps applying in liquid-propellant rocket engines are compared with data for pumps produced to use in another industrial applications. Obtained results allow to enhance numerical modeling accuracy to optimize lighting processes for designed and upgraded liquid-propellant rocket engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubovick S. E., Soshnikov D. V. An analysis and optimization of intelligent business processes based on structured functional decomposition for knowledge fields. Aerospace MAI Journal, 2006, vol. 13, no 1, pp. 36-44. Techniques and tools are developed for a structured functional decomposition of knowledge fields. The development is based on knowledge representation technologies. A formalization is carried out for model theory based operational semantics of extended functional model. Furthermore algorithms are obtained for a search of special segments within business processes, including cycles, deadlocks etc., by means of the extended functional model. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Beliayev E. N., Kanalin Y. I., Romasenko E. N., Chervackov V. V., Beliayev D. E. Turbining of boost pumps for liquid-propellant rocket engines. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 26-31. An analysis and generalization are carried out for properties of boost pumps intended for liquid-propellant rocket engines in regard to turbining and braked shaft modes. Experimental data for the boost pumps case are compared with data for pumps produced to use in another industrial applications. Obtained results allow to enhance significantly numerical modeling accuracy to optimize lighting processes for designed and upgraded liquid-propellant rocket engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinogradov Y. I., Gusev Y. A., Zolotukhin V. S. Research techniques for stress concentration in shells. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 61-65. New numerical methods are offered to analyze stress concentration in shells. An efficiency of these methods are caused with implementation simplicity as well as low consumption of computer memory and processor time. Another characteristic feature of the methods is controlled solution error for stress analysis problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volkov-Bogorodsky D. B. Application of block analytic-numerical multiple-field technique for acoustical problems. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 51-60. A block analytic-numerical multipоles technique is developed for solving of acoustical problems. The technique differs from the finite-element method due to approximation scheme used to describe a solution required. The approach offered is applied to solve some acoustical example problems. Obtained results affirms computational efficiency of the block analytic-numerical technique for solving of boundary value problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
. ., Samokhina K. E., Sorokin A. E. Functioning analysis for actuator of electrical-driven control system powered with combined current supply. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 66-73. Electrical-driven actuators for flying vehicle control surfaces attract more attention in recent years, but for all that power supply aspects do not consider properly in most cases. However current supply type and its characteristics influence considerably on dynamical properties, mass and size of autonomous electrical-driven control systems. An integrated functioning analysis is carried out to reveal performances for some electrical-driven control system powered with combined current supply. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Djigan V. I. Parallel linear-constrained RLS-algorithms for adaptive filtering. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 81-92. Computational procedures are presented for new sliding window linear-constrained regularized recursive least squares (RLS) adaptive filtering algorithms. These procedures are fitted to a parallel implementations by means of four processors. The algorithms are obtained for a general case of multi-channel adaptive filters with unequal number of complex-valued weights in the channels. Special cases of the algorithms can be used for single-channel adaptive filters or for filters with real-valued weights. Complexity estimations and simulation results are considered also for the algorithms. These simulation results demonstrate a computational efficiency of the algorithms in case of non-stationary signal processing. The algorithms can be used to solve various problems related to linear-constrained adaptive filtering for non-stationary signals. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dreytser G. A., Lobanov I. E. Extreme intensification of heat transfer in tubes by means of artificial flow turbulization for gas heat-carrying mediums with variable thermophysical properties. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 18-25. A new theoretical model is developed to compute extreme values for heat transfer and hydraulic resistance in the conditions of intensification in tubes by means of artificial flow turbulization for gas heat-carrying mediums with variable thermophysical properties. The model describes corresponding processes for a wide range of Reynolds and Prandtl numbers. Obtained results allow to predict enhancement reserves for non-isothermic heat transfer. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubrovin A. V. An estimetion of emitter coordinates by means of a passive Doppler-based system. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 93-97. A technique is considered to estimate coordinates of some emitter by means of two movable passive measuring stations. The measuring is based on a delay between signals and relative compression of the signal caused with the Doppler effect. Expressions are derived to describe a measurement accuracy for the emitter coordinates using the system offered. It is shown that consideration of Doppler effect as a compression of a signal relative to another one allow to enhance the measurement accuracy with bandwidth increasing for the emitted signal. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M. An influence of hydrodynamic non-stationarity on heat-transfer and hydraulic resistance coefficients for heat-transfer medium turbulent flow within a tube. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 32-36. Experimental data are obtained about a structure of turbulent flow within a circular-section tube for stationary and hydrodynamically non-stationary gas flow regimes. Heat-transfer and hydraulic resistance coefficients are computed for non-stationary air flows using these data. The results can be used for engineering analysis of high thermal-stressed structural elements. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Perminov A. N., Ptoushkin A. I. An investigation of relationships between technical state monitoring and efficiency for ground-based space industry infrastructure. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 74-80. An approach is considered to model a maintenance system for objects of ground-based space industry infrastructure. This infrastructure includes a subsystem to monitor technical state of the objects. Some important information can be obtained by means of investigations based on the model offered. The information of this kind are needed to make demands associated with authenticity of inspection, repair and prediction for technical state of the objects as well as to make decisions about their operating regimes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sinitsyn V. A., Churkin V. M., Aleksandrov O. A. Mathematical modeling of solar sail deployment for a space vehicle. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 37-43. A mathematical model is suggested to describe deployment process for a solar sail meant for an advanced space vehicle. The sail has a new design, it is composed of reflecting surface and flywheel with rotational movement drive. The deployment process consists of four successive stages including extension of the sail and the flywheel in folded condition then deployment of the flywheel and reflecting surface expansion of the sail. The model offered allows to usea standard software to investigate separate stages of the deployment processes as well as these processes as a whole taking into consideration a body motion of the space vehicle. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bourak S. B., Firsanov V. V. Computation of deflected and vibro-dynamical modes for structure of adaptive catapult devices by means of finite-element method. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 3-12. Finite-element models are developed to compute deflected and vibro-dynamical modes for a system which consists of guided missile, adaptive catapult device and aircraft. The models with different complexity level are generated depending on particularity degree in structure description during various design stages. These models are used to investigate an influence on structural strength such factors as nonlinear mechanical constraints as well as elastic and inertial properties of system units. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shklyarchuk F. N., Tyutyunnikov N. P. Twisting control for elastic torsion box wing by means of internal adjusted braces. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 13-17. A new approach is suggested to control twisting of elastic torsion box wing. The control is carried out by means of internal adjusted braces which are made as steel tapes or cables. A technique to find adjusting tensile forces and length increments for the braces is demonstrated on example related to rectangular torsion box for a wing. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vinogradov V. S., Ivanov A. V., Pal'ciz A. A., Cheredov V. V. Integral absorptive power of dielectric-based metallic coatings for infra-red waves. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 44-50. An integral absorptive power (thermal radiation coefficient) of dielectric-based metallic coatings is investigated for an infra-red waves case. Various coating structures were studied for different thickness values. It was established that reducing of the coating thickness leads to enhancement of the thermal radiation coefficient from a typical coating value to a typical substrate layer one. A physical interpretation is offered for absorption-emission processes related to the coating-substrate systems. A simple semi empirical model is derived to match computational and experimental data. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubrovin A. V. Adiustment features of antenna-feeding system in direction finding complexes for HF band. Aerospace MAI Journal, 2005, vol. 12, no 3, pp. 98-102. Adjustment features of antenna-feeding system in direction finding complexes for HF band are considered. The consideration is carried out for some example of a phase measurement in a two-channel system. Major factors are revealed which influence on measuring accuracy for a difference of phases. Some techniques are offered to compensate these factors as well as a criterion to estimate a degree of the compensation. An average measuring error can be reduced from 3.980 down to 1.590 value using these techniques. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pogosyan M. A., Liseitsev N. К., Ryabov V. A. Evolution of scientific foundations for aircraft design and problems of personal training. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 5-9. A content of the “Aircraft Design” course is under consideration. The content analysis is based on evolution and progress in aviation as well as scientific foundations of problem solving in regard to aircraft designing. A contribution made scientists and lecturers of the Aircraft Design Department at the MAI is demonstrated to develop scientific foundations of aircraft design but also to manage a personal training. Important areas and training techniques are revealed based on computer-aided design methodology to prepare qualified personnel which will able to apply modern information technologies. Tendencies are analyzed as for relationship between formalized and informal methods of design process. Possibilities of further improvements in design techniques and design management procedures are discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M., Goryunov N. P., Demin V. Y., Lapshin V. P. Designing of the MAI-223 new generation light multi-purpose two-seat aircraft. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 10-17. Design of the MAI-223 new generation light multi-purpose two-seat aircraft is considered. This aircraft is developed at the Special Design Bureau for Experimental Aircraft Construction at the MAI. Previous designs of the Design Bureau are described. Some issues are discussed for the MAI-223 design including a choice of aircraft concept; possible fields of application; a market capabilities of the aircraft; main performances and design features; current status of the project. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Efremov A. V., Ogloblin A. V. Progress in investigations of aircraft-pilot systems. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 18-29. Results of investigations are analyzed in the field of aircraft-pilot systems, which are carried out at the MAI during last 20 years. The results include methodological support and algorithmic tools to study characteristics of pilot actions and properties of aircraft-pilot systems. Furthermore some new regularities are revealed for a pilot’s behavior in manual control tasks as well as appropriate mathematical models are developed. The methodological support is a basis for system approach to solve application problems discussed briefly in the paper. An effectiveness of the approach is demonstrated for some application problems including generating indexes to choose handling qualities of aircraft, synthesis of manual control systems, adequacy enhancement for results of aircraft handling qualities estimations by pilots in flight and ground-based simulation experiments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Artamonova L. G., Radtsig A. N., Ryzhov Y. A., Semenchikov N. V., . ., . ., Yakovlevsky O. V. Research carried out at the MAI in the field of separated and jet flows around aircraft and their parts. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 31-48. Results of theoretical and experimental investigations are discussed for a broad class of three-dimensional separated flows around aircraft bodies and wings as well as around a whole vehicle configuration for transcritical and supercritical angle of attack areas. The experimental investigations are carried out in the MAI wind tunnels for Reynolds number values from the 0.26106-3.4106 м-1 region. Some general regularities are revealed for generation and transformation of separated flows and vortex systems. Relationships are found between a flow structure and shape of aircraft parts together with flow conditions for large angle of attack values. A possibility is discovered to use interaction of vortex structures in wing systems and vehicle configurations to enhance their lifting properties for large angle of attack values. It is demonstrated that a blowing of jets is an effective means to control a flow and aerodynamic characteristics of a vehicle for nonseparated or separated flows. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tischehko M. N., Artamonov B. L., Zavalov O. A., Mojzyh E. I., Maslov A. D. Development of application methodology for computer-aided techniques to design rotary wing aircraft and their systems. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 49-61. An experience is generalized which is accumulated by lecturers of the Helicopter Design Department at the MAI in the field of CAD/CAM/CAE technologies use for various stages of a design process as applies to rotary —wing aircraft. Capabilities are analyzed for some low-end (Autocad), middle-end (MicroStation, Mechanical Desktop, Inventor, SolidWorks) and high-end (CATIA) software packages (with their classification based on a complexity level for appropriate package). These software tools are rated from the point of view of their potential to produce two-dimensional and three- dimensional mathematical models for aircraft units and assemblies as well as for aircraft as a whole. Applications of virtual spatial parametric models are considered to solve these problems and to generate data bases for typical aircraft structural units. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kofman V. D., Poltavets V. A., Mulkidzhanov I. K. Some lessons of aviation accidents. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 62-71. A trend for accident rate is considered as regards the civil aviation of the Commonwealth of Independent State (CIS). The trend analysis is based on representative statistical data for the last 20 years period. Authors make an attempt to classify and generalize some lessons of aviation accidents. This discussion is carried out for aircraft with gas turbine engines. Some negative factors and causes of accidents are revealed for the most dangerous flight events and situations including aircraft stall, icing, air and ground collision, aircraft overloading etc. Recommendations are offered to prevent accidents of the considered classes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krasotkin A. A., Karapetyan T. S. Conceptions of a light multi-purpose aircraft. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 72-80. Conceptions of a light multi-purpose aircraft for regional air lines are developed basing on analysis for aviation in regions of the Russian Federation. A necessity is shown to develop a family of the aircraft. A basic aircraft type of the family is a multi-purpose aeroplane with a biplane aerodynamic design. A passenger version of the aircraft is realized with a high-wing design. Some principles are offered to provide required level of flight safety and to reduce operating costs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sokolovskii G. A., Smol'skii G. N. Main ways of development for air-to air missile weapon. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 81-85. A brief history is outlined for development of air-to-air guided missiles in the Soviet Union and in the Russian Federation. Main ways of future development and perfection of the missiles are also considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Turkin I. K., D'yakonov D. A., Zavalov O. A. Principles and approach to development of remote-piloted low-sized aircraft for civil applications. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 86-90. Developments of remote piloted vehicles (RPV) was carried out at the MAI since 1975. These RPV was intended to use for civil, military and special purposes. Eight RPV types was developed altogether including three of them which was brought to prototype and flight testing stage. Besides a remote piloted helicopter (RPH) was developed in the latter half of the nineties. The RPH named «Voron» (Raven) has 40 kg maximum take-off weight and can carry up to 18 kg payload. Design features and performances are considered for the RPH as well as for remote piloted aeroplanes “Lesnik” (Forest-guard ) with 36 kg maximum take-off weight and 12 kg payload and “Vorobey” (Sparrow) with 0.8 kg maximum take-off weight which are developing now. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sevast'yanov N. N., Verkhoturov V. V. Risk management techniques in spacecraft development for satellite communication systems. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 91-100. An experience of the Gascom Joint-Stock Company is described to manage technical risks associated with ensuring of required reliability for spacecraft radio-electronic equipment. Requirements are stated for a management system intended to deal with reliability of the equipment. Suitable management principles are suggested. An appropriate structure for some information subsystem is founded to enhance efficiency of corresponding decision making process. Implementation results are reported and analyzed to demonstrate using of the approach in the Yamal-200 spacecraft development process. This spacecraft was accepted for operation in the year 2004. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M., Lokshin M. A. Engineering systems with boosted operational modes and adaptive structure. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 101-104. An effectiveness problem is considered for technical systems with boosted operating modes. It is possible to decrease adjusting powers by 1,5-2 times by means of short-term operating pressure increasing. This approach has been proved theoretically and confirmed experimentally. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chepkin V. M., Marchukov E. Y. From the first Soviet turbojet engine to a modern fifth-generation engine. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 105-111. A brief history of the Luylka Research Center affiliated with Luylka Saturn, Inc. is considered. The Luylka Research Center is one of leading firms of the Russian aerospace industry dealing with development of turbojet engines for a military aviation as well as with development of power modules for gas-compressor units and electric power stations. Some technical descriptions are given for engines and power plants developed at the Luylka firm since1946 and to present day. Managers and principal specialists are noted with relation to contribution to activities of the firm. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Popov G. A. Electrical rocket engines-their development in Russia and a contribution of the Moscow Aviation Institute. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 112-122. Evolution of electrical rocket engines is considered from the very beginning until present including a contribution of the MAI. The present state of research and development is described and analyzed for the electric rocket engine area as well as problems needed to solve. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Skibin V. A., Kraiko A. N. Computational gas dynamics and mathematical modeling for devices of essentially new types. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 123-141. Some capabilities are demonstrated by a set of examples for techniques of computational gas dynamics. These techniques are used to describe processes in various non-conventional propulsion and power plants including pulse-detonation engine, ejector thrust augmenter, engine with rotating valve, “wave rotor”, “inertial thermonuclear” power plant as well as to derive and optimize their performances. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rodchenko V. V., Obmornov V. A. Multimodule subterranean jet devices. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 142-144. Possible application areas are discussed for subterranean jet devices. These devices are a new generation tool to move within a soil with high speeds. A version of an internal layout is considered for multimodule subterranean jet device meant for a hole formation within a soil. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Karpyshev A. V. High-efficiency devices based on aerospace technologies for fire fighting by means a fine-air water. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 145-148. Some engineering problems are considered to develop advanced technologies for high-efficiency fire fighting by means a fine-air water. The development based on aerospace technologies was carried out at the Research Center for Advanced Technologies at the MAI. Main features and parameters of the designed fire fighting devices are examined. Implementation possibilities for advanced fire fighting devices are analyzed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Veretennikov V. G., Sinitsyn V. A. Analytical principles to construct mathematical models of dynamics. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 149-155. An application of some fundamental principles of mechanics is considered. A connection release principle is applied to restricted dynamical systems with constraints. A comparison is carried out for a variational-form energy principle and a principle of variable action. A sluggishness principle is offered in addition to inertia principle. Some examples are discussed for a mathematical formalization of determinancy principle. An application are demonstrated for a logical predicativity principle by means of models for a variable-mass material point and using a problem of efficient start maneuver for a rocket launch in a potential field. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorshkov A. G. Mechanics for interaction of deformable structures with continuum mediums and physical fields. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 156-163. Some research results are surveyed and discussed as concerns interaction of structural components of thin-walled structures and rigid bodies with continuum mediums and physical fields. Special attention is devoted to development of efficient numerical and analytical techniques to solve this sort of problems. The results considered are obtained by members of a special scientific team «Nonstationary dynamics of continuum mediums and structures». | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Evdokimenkov V. N., Krasil'shchikov M. N. A combined technique for pattern recognition based on Bayesian classification and a comparison with prototype. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 164-174. A combined technique for pattern recognition based on Bayesian classification and a comparison with prototype is considered and discussed. Consolidation of possibilities for traditional techniques enables to obtain simple practical implementation of recognition algorithms together with appropriate reliability level for results especially in case of limited training samples. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Polkovnikov V. A. Synthesis of main actuator parameters for autonomous servo drive of control surfaces for flying vehicles ensuring complex motion laws. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 175-184. Design relationships are offered to synthesize parametrically actuators for autonomous servo drive of control surfaces of flying vehicles. The relationships allow to compute values of main parameters for these servo drive of control surfaces realizing complex motion laws for vehicle control surfaces. The laws implemented represent an algebraic sum of slow varying control laws and harmonic component used as a typical movement for a vehicle stabilization loop. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ratner V. D., Reutov V. G. A significance and perspectives of the Earth integrated radar monitoring. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 185-194. Functions and significance of an aerial radar monitoring are analyzed from the point of view of the Earth global monitoring system. Future trends are considered for this system based on international agreements related to the Earth remote observation activities. An importance of helicopter-based radar systems is proved for the Russian Federation circumstances. These systems are capable to solve some other problems in addition to monitoring including rescue operations as well as life support operations for little-developed regions which are difficult of access. Several examples of radar aerial systems are discussed developed by the “Corporation Phazotron-NIIR” Joint Stock Company. The systems are capable to solve now the problems mentioned above. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sloka V. K., Teplyakov I. M. New radio-digital platforms for aerospace systems intended for high-speed data transfer. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 195-203. Design foundations and main features are considered for a new generation of aerospace high-speed reconnaissance and information systems intended for the theatre of war. The systems can be implemented using relay transponders located on unmanned aerial vehicles and satellites. Some problems related to these new radio-digital high-speed data relay distribution systems are discussed including requirements formulation and structure selection, computation of radio link power budget for a two-stage aerospace retransmission scheme, main features of a spacecraft-based retransmitter, general algorithm and interaction scheme for a retransmitter —subscriber system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pigin E. A. Past, progress and perspectives of middle-range guided missile mobile air-defense complexes for land forces. Aerospace MAI Journal, 2005, vol. 12, no 2, pp. 204-215. A brief history is outlined for developments carried out at the Tikhomirov Research Institute for Instrument Making (RIIM) including activities performed in close collaboration with the MAI. In the beginning radar systems was developed for interceptors then energies of RIIM was switched to development of guided missile mobile air-defense complexes for land forces. A description of main features and performances are given for the air-defense complexes «Kub», «Buk» as well as for their various versions which was developed and produced the NIIR in cooperation with some other enterprises of Soviet and Russian aerospace industry. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M. Manpower training for aerospace industry using applied research and developments. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 9-14. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shustrov Y. M., Afanas'ev P. P. Aircraft Engineering School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 15-23. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chervackov V. V. Engines for Flying Vehicles School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 24-34. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Postnikov V. A. Control Systems, Informatics and Electrical Power School . Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 35-40. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shevtsov V. A. Radio Electronics for Flying Vehicles School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 41-44. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 45-51. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Alifanov O. M., Mikhailov V. V., Rodchenko V. V. Aerospace Engineering School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 52-57. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Polkovnikov V. A. Robotics and Intelligent Systems School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 58-65. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Krasilnikov P. S., Puntus A. A. Applied Mathematics and Physics School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 66-73. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorshkov A. G., Nartova L. G. Applied Mechanics School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 74-89. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mavrodi S. I. Humanities School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 90-95. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Prozorov D. E. Foreign Languages School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 96-98. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Goncharenko V. I., Mareev Y. A., Yurov N. N. Military Training School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 99-107. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khomutov V. A., Krol' T. T. The «Strela» School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 108-109. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveev Y. A. Space Technology School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 110-111. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tarasov S. I., Chilikin I. N. The «Cometa» School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 112-113. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gerashchenko A. N., Nazarenko A. V., Yurov N. N. MAI Educational subdivision at Serpukhov. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 117-118. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kleimenov S. A., Grubrin I. V., Antipova T. A. The «Radio Engineering Higher School» School. Aerospace MAI Journal, 2005, vol. 12, no 1, pp. 114-116. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kessaev K. V. Some features of precombustion ingnition in liquid-propellant rocket engines. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 15-21. An influence of incendiary jet chemistry on fuel firing is investigated as applied to combustion chambers and gas generators of liquid-propellant rocket engines. It is shown that ignition quality of the incendiary jet is is increased essentially for a case of fuel of oxidizer excess depending on used fuel. The incendiary jet with such a mixture can be produced by means of a gas-dynamical igniter with resonant cavity to heat inflammation of a starting fuel doze. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tishkov V. V., Firsanov V. V. About model formulation for longitudinal impact on compound bar with relation to investigation of safety for complex aircraft systems upon emergency conditions. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 3-10. A technique is offered to find accelerations for elongated body at the moment of its longitudinal impact with perfectly rigid barrier for collision speeds up to 100 m/s. The body is modeled as a bar with geometrical and inertial properties varied stepwise along its length. It is assumed that stringback of the bar after initial impact is not taken into account; a deflection of waves is not considered during their passing through bar parts with different stiffness; the bar is made of isotopic metal material; internal contents of the body is reduced to some equivalent stiffness; sonic propagation speed along parts of the bsr is considered as a constant. Differential equations described oscillations of bar parts subject to appropriate initial and boundary conditions is solved using Laplace transformation as well as infinite series expansion for required displacements. A numerical example is given to demonstrate efficiency of the technique. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shklyarchuk F. N., Twin K. . Estimation of coefficients for apparent additional fluid masses within elastic oscillating cavities. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 11-14. Aircraft wing compartments bounded with spars, ribs end lower skin can be filled partly with liquid fuel. A flowability of the liquid influences on dynamical properties and flutter behaviour of elastic wings. In order to evaluate this influence it is necessary to solve a fluid oscillation problem foe each compartment of the wing and to find appartment additional fluid masses then to derive equations of elastic oscillations for considerate structure. These equations are solved by means of a variational technique. The technique reduces the original problem to ordinary differential equation set. The derived equations are solved with numerical integration. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Semenov V. V., Min L. Z., Ivanov I. E., Kryukov I. A. A gas-dynamic igniter equipped with supersonic nozzle. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 22-27. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dreytser G. A., Isayev S. A., Lobanov I. E. Computation of convective heat transfer in a tube with repeating protrusions. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 28-35. A theoretica investigation is carried out for a convective heat transfer in a tube with periodically located protrusions. The investigation is performed by means of multiblock computational techniques for Reynolds equations solved with factorized finite-volumetric algorithm. These equations are closed using Menter transfer tangent tension model as well as energy equation for different scale intersecting structured grids. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zuyev Y. V. A mathematical modeling of two-phase nozzle and jet flows within plants intended to lay coatings by means of gas-dynamical technique. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 36-40. Some theoretical results are discussed concening to two-phase flows in nozzles and streams used to lay coatings by means of a gas-dynamical technique. An approach is offered to calculate sequentally properties of these flows. The approach enables to select a sort and parameters of gas, as well as geometry for the nozzle. Furthermore a size of a coating region is predicted depending on distance between the nozzle and a processed component surface. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M. Frequency spectrum investigatios for pulsations of gas flow in tube for nonstationary conditions. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 41-45. Experimental data are obtained about a structure of turbulent stream for a flow within a circular pipe. Stationary and nonstationary modes of the flow are considered. Frequency spectra are calculated for axial and radial velocity fluctuations based on the data. An analysis is carried out for influence of hydrodynamic nonstationarity on causes of generating and propagation of the turbulent fluctuations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishanina T. V. Elimination of oscillations for elastic system after its fast movement and rotation. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 46-51. Equations are obtained as well as their solutions for oscillations of an elastic system after its fast finite transition and turning caused with one half-cycle sinusoidal-wave forse or kinematic impulse. It is shown that the oscillations and motion of thr system stop simultaneusly at the end of the impulse action if a duration of the impulse exceeds a natural period of the system by an integer factor. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tsarenko P. B., Yanyshev S. S. Gas-dynamical parameters of two-phase high-concentrated jet influenced with drifting flow. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 52-57. A numerical simulation is carried out to investigate gas-dynamical parameters of two-phase high-concentrated jet influenced with drifting gas flow. This investigation was inspired with a problem of fire-fighting by means of helicopter-based plant which ejects high-speed high-concentrated two-phase fire-fighting jet. The drifting gas flow considered is a stream caused with the helicopter main rotor. Parameters of the jet are studied depends on velocities of inlet jet main rotor stream. Typical features of interaction between inlet jet and rotor stream are described. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Myakochin A. S. Heat and mass exchange for thermo-destruction of hydrocarbon fuels within pipe channels. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 58-65. An experimental study is carried out to analyze heat and mass exchange for thermo-destruction process in regard to hydrocarbon fuels in conditions of pumping through heated pipe channel. The processes are studied for such condition range as pressures from 0.1 MPa to 8.0 MPa, intake fuel temperature 400—500°C, outlet pyrogas temperature 550—750°C, and for Reynolds numbers range from 2· 103 to 1.4· 104. Pressure increasing as well as residence time (τ from 0.005 s to 0.2 s) for fuel within the channel leads to rising gasification magnitude and calorific effect for thermo-destruction reactions of hydrocarbon fuels. A temperature of gasification beginning decreases for such conditions. For a large heat loadings case is revealed a sharp decrease of heat transfer caused by flow laminarization effect. The fuel thermo-destruction inhibits temperature rising for channel walls accompanied with heat transfer decreasing if the reaction runs in the kinetic mode. The heat transfer decreasing becomes as a «thermal explosion» if the reaction runs in a diffusion region. Bounds of decreasing heat transfer region are obtained for thermo-destruction of hydrocarbon fuels as well as experimental data are generalized basing on local heat transfer data using Damkeller number. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plokhikh A. P. Realization features of radio metering within metallic vacuum chambers. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 66-78. Some problems of radio engineering measurements are discussed as applied to vacuum chambers. Basic requirements are formulated on additional equipment needed for these chambers. Recommendations are proposed to construct the chambers. Some versions of the chamber construction are considered as well as results of experimental metering for several versions of modeling objects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Neudobnov N. A. VHDL descriptions generation for digital systems basing on Petri net model. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 79-89. The features of mathematical modelling of up-to-date digital control and data processing systems are described in this paper. The requirements to the mathematical apparatus are stated and the necessity of provision of automated conversion the mathematical model of a digital system to the input format of the up-to-date synthesizing CAD. Some of original author’s constructions with VHDL language whish permit adequately represent mathematical models of digital systems, given with the help of strict — hierarchical synchronous Petri nets are considered. The obtained results provide possibility of organization of a through computer-assisted design of digital systems from a stage of mathematical modelling up to a stage of low level logic synthesis, that allows considerably reduce time of development, lower complexity and improve the design’s quality. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Russkikh N. P. A blind deconvolution algorithm. Aerospace MAI Journal, 2004, vol. 11, no 2, pp. 90-94. A computational algorithm is considered to restore multi-dimensional signal based on convolution with some uncertain function. This algorithm is based on repeated filtering and makes possible to restore a signal with relatively low computer time expeditures. The algorithm may be used in situations with uncertainty in restored signal carrier and in initial approximations for the signal. An example of restore problem solving is demonstrated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golubev I. S., Vu Hoatien .. .. Criterion of estimation for vehicle perfection. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 3-6. A conceptual design problem is considered as some optimization problem. An optimality criterion needed to solve this problem is interpreted as an estimation of a vehicle perfection grade. The optimality criterion is derived from results obtained by means analysis of application level for achievements of up-to-date technological progress. It is demonstrated that a quantitative assessment of a degree for the application level can be expressed through using efficiency of the vehicle mass. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Liu Deguang .. .. Flatter analysis for wingless missile. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 7-11. A high-fineness ratio missile body subjected to lateral oscillations is considered as a cross bending beam while horizontal tail is operated as an elastic plate connected with the body by means of some cross bending and torqueing elastic unit. An aerodynamic pressure for the horizontal tail due to supersonic airflow is calculated based on the piston theory. Expressions for aeroelasticity oscillations are derived as Lagrangian equations for generalized coordinates, which describe eigenmodes of symmetrical oscillations for the body combined with the horizontal tail. Computation of characteristic oscillations is carried out with the NASTRAN software. A flutter speed is found for a horizontal tailed missile. Some numerical simulation results are demonstrated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidov A. S., Kashelkin V. V. Criteria selection for a mechanical properties prediction of structural materials as well as estimation of structure remaining life. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 12-17. Results are obtained for structural materials to assure a prediction their mechanical properties using hardness number. The results are based on statistical treatment of experimental investigation undertaken for the materials. A prediction technique presented is founded on the Larson-Miller criterion. Some possible approaches are considered to evaluate a remaining life for silphon components. This characteristic is computed according to frequency properties of the silphon component. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bobkov A. V. Theoretical pressure increasing for wheels of vehicle rotary pumps. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 18-21. Results of analytical estimation are described and discussed for a problem of pressure increasing for wheels of aerospace vehicle rotary pumps. It is suggested to increase the pressure by means of flow pulsation smooth-out devices mounted just behind the pump wheel. Some numerical simulation results are demonstrated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zuyev Y. V. Using of mathematical model for two-phase jet to compute parameters of plume for a fuel atomizer. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 22-26. A mathematical model for some two-phase jet is proposed to compute plume parameters for a propellant atomizer. Results obtained by means of this model are compared with experimental data. The comparison demonstrates that accuracy of suggested model is quite enough for engineering purposes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dreytser G. A., Kraev V. M. Investigations of fluctuation frequency spectrum for gas flow in a tube. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 27-33. Experimental data are obtained regarding turbulent flow patterns in a tube with a circular cross-section in cases of isothermic and non-isothermic flow regimes. Frequency spectrums are computed for axial and radial velocity fluctuations based on these data. An analysis is carried out for influence of non- isothermic regimes on mechanisms of generation and evolution for turbulent fluctuatins. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M., Inozemtsev A. A. Closed multiloop thermodynamic cycles with a mix of heterogeneous actuating mediums. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 34-39. A theory is proposed for closed multiloop thermodynamic cycles with a mix of heterogeneous actuating mediums. A possibility is demonstrated to use these cycles in spacecraft power plants without heat dropping into space as well as in transport and energy systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chvanov V. K., Fatuev I. Y., Konovalov S. G., Bogushev V. Y. Utilization possibility analysis for assemblies out of the 15D117 jet propulsion as applied to liquid oxygen-kerosene propulsion. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 40-45. It is proposed to use the chamber body of the 15D117 liquid propellant rocket engine for development of a new oxygen-kerosene RD-120U engine intended for the first stages of the “Quantum”, “Edinstvo” and “Onega” launchers. The 15D117 engines are released because of the Russian Federation international obligations in the field of arms reduction. Such approach allows to reduce essentially development period and expences for the for the RD-120U engine. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plokhikh A. P., Malko E. V. Techniques for charging effect analysis in regard to integration of electric propulsion with spacecraft. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 46-55. Simulation techniques and appropriated software are considered to analyze charging effects with respect to integration of electric propulsion with a spacecraft. Basic physics is considered to simulate charging effects caused with Earth’s magnetosphere as well as numerical test results in regard to realistic spacecraft mathematical analyzed. Practical recommendations are suggested to use the software for a spacecraft design support. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Musin S. M. A model of transmission processes for energy distortion components in alternating current power-supply systems. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 56-63. A mathematical model is submitted for transmission processes of energy distortion components in alternating current power-supply systems. The model includes and combines descriptions and performances for various kinds of on-board systems. As a result this model allows to get out data associated with the power-supply system itself as well as with the on-board systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishanina T. V. A controlled finite-angle twisting for an elastic bar. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 64-68. A twisting of an elastic bar relative to its end is considered under the assumption that a motion of another end of the bar is specified. A fore or a torque is used to control the motion. The force (or the torque) is unknown and its value is to be found. This sort of problem emerges in studies of rapid movement of arm manipulators, automated assembly of space framed structures and so on. These problems are solved to assure some predefined motion and to eliminate elastic oscillations for a certain point of the bar. Equations for a turning movement and elastic vibrations of the bar is derived. Some examples are discussed to compute a control force or a control torque providing solution of the problems mentioned above. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Myakochin A. S. Heat transfer and heat resistance of cross-streamlined ring-grooved tube bundles. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 69-74. An experimental study is carried out to analyze mean heat transfer as well as hydraulic resistance for a tube located within a bundle in the leading row and in some deep-laid one. Experiments are performed for a range of the Prandtl numbers from 0,7 to 0,7 and for Reynolds numbers range from 1,2×103 to 7×104. It is found that the heat transfer of leading rows for a staggered-tube bundle is by 21-49 % less than the heat transfer of deep-laid rows depending values of the Reynolds number and some other parameters. In case of low Reynolds numbers a volumetric heat transfer efficiency for smooth tubes and circular-grooved ones are identical for same configurations. For high Reynolds numbers smooth tube bundles are more effective than circular-grooved ones. The experimental results obtained are generalized and compared with data from other researchers. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yudin V. N. Object secrecy from supervision facilities. A secrecy of object position. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 75-80. An object secrecy from supervision facilities is considered with reference to a secrecy of object position. A quantitative description is introduced for the secrecy of object position. The description is based on entropy indexes. Conditions for optimal secrecy of object position are derived for a case of zone with some supervision facility units. An implementation of the conditions is evaluated to generate disturbances for the supervision facility. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Plokhikh A. P., Vazhenin N. A. An analysis for influence of electromagnetic disturbances caused with electric propulsion on sensitivity characteristics of on-board spacecraft radio systems in the super-high frequency band. Aerospace MAI Journal, 2004, vol. 11, no 1, pp. 81-93. An analysis is carried out for influence of electromagnetic disturbances caused with electric propulsion on sensitivity characteristics of on-board spacecraft radio systems. An integrated approach is used to describe a radio channel and the electric propulsion as a unified electrodynamics system. Theoretical and experimental techniques are presented to estimate a realistic sensitivity of receiving channels in the presence of operating electric propulsion. Recommendations are suggested to integrate electric propulsions with spacecraft radio systems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Matveenko A. M., Alifanov O. M., Karp K. A., Matrosov V. M., Stolyarchuk V. A. A development of open education system in the MAI based on modern and advanced information technologies. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 3-23. Russian aerospace education system is in a hard situation now. It is caused mainly with insufficient level of state financial support. Additional resources could be involved by means of educational process intensification including increasing number of students per one teacher as well as by means of increasing number of students paying fee. Modern and advanced educational technologies including Internet-based ones can provide and support such processes. Open aerospace education technologies concern to this class of technologies and promise to improve methodological and technical level of education processes. Furthermore these technologies provide possibility of international cooperation and integration with international education system based on free market conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ivanov V. V., Marakhovskii I. V. Selection of aircraft storage batteries. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 24-29. An approach is offered to select aircraft storage batteries with reference to various lifetime stages. Selection criterions are formulated for the batteries based on operational requirements taking into account maintenance cost and other constraints. Hierarchy technique proposed by T. Saati for expert estimations is used to derive corresponding decision process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kessaev K. V. A gas dynamics of a resonance tube. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 30-37. A physical nature is studied for origin of periodic oscillation in cylindrical cavity caused with inflow of under expanded gas in the cavity. The tube of this kind is named usually as a resonance tube. Research fulfilled was inspired with a problem of multiple ignitions for liquid propellant rocket engines. It is demonstrated experimentally that periodic oscillations have a surging nature and are followed with the peak heat emission. A gas dynamical model is derived for shock-wave oscillations based on experimental data. This model allows to discover conditions of maximal compression and heat emission in the resonance tube. The results obtained open up possibilities to design effective devices for gas-dynamical heating and ignition of a blended fuel within the resonance tube. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Galitseysky K. B. A numerical modeling algorithm to investigate emitting of jet propulsion exhaust gas. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 38-43. A computer technique is presented to simulate heat emitting for chemically reacting two-phase jet flows. The technique is based on discovering of optical properties for the flow as well as on numerical algorithm to solve an emitting transport equation by means of discrete-ordinates method. This technique enables to investigate absorptance and radiant emittance for fuel combustion materials of jet propulsions. It is possible to compute emitting for chemically reacting jet flows. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nadiradze A. B. About distribution function for particles of liquid-dropping phase in small-thrust liquid-propellant engine. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 44-46. A mathematical model is presented to describe distribution of dimensions for particles of liquid-dropping phase in outlet flow of small-thrust liquid-propellant engine. Main problem attached to selection of distribution function consists in strong dependency for density of outlet flow from particle outlet angle. It is offered to solve this problem by means of replacement a local distribution function defined along a separate line of flow with some distribution function for a whole ensemble of particles discharged with the engine. It is possible to use a simple power function as a distribution function in such a case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khaustov A. I., Zhdanov I. L., Sergievskii E. D., Ovchinnikov E. V. A liquid flow computation in channels of peripheral pumps. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 47-51. Numerical results are presented as applied to an analysis of viscous incompressible liquid flows within peripheral pump. Pressure fields and velocity profiles are made for a hydraulic channel of the pump. It is demonstrated that pressurization is taken place according to a near-linear law for the whole length of a side channel. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ones I. V. Necessary conditions for a fuel conversion reaction. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 52-67. A technique is offered to increase effectiveness of burning devices including internal-combustion engines. The technique is based on partial using of exhaust energy for conversion of a fuel and an engine exhaust into some another fuel with enhanced energetic properties. An analysis is carried out to recognize adequacy of heat contained in exhaust to implement energy conversion process. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyutyunnikov N. P. A computation of stress-strain state for thin-walled structures stressed with a set of point forces. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 68-73. A stress-strain state are investigated for thin-walled axisymmetric structures stressed with a set of point forces. Two approaches are used. First of them is based on using of the UAI/NASTRAN finite element program. This approach dominates presently in an engineering practice and when it is used any other techniques even are not considered. Second approach is based on analytical modeling. It is implemented using Matlab tools. A comparison of results obtained by means of these two approaches allows to formulate some recommendations for collaborate using of numerical and analytical tools. Such a kind of collaboration leads to more effective processes of stress-strain analysis for thin-walled structures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lianzberg V. P. A load-carrying ability for flat-based acryl-made illuminators loaded with an ambient hydrostatic pressure. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 74-79. A load-carrying ability is studied for flat-based organic glass-made illuminators with a glass unit formed as a disk or a truncated cone. The illuminators are loaded with a long-time ambient hydrostatic pressure. Structural alternatives are reviewed for this sort of illuminators. Experimental investigations are carried out for cases of short-time and long-time loading. It is demonstrated that the structural version offered provides improvement of the illuminator load-carrying ability for the case of long-term hydrostatic loading. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grinev A. Y., Voronin E. N., Gigolo A. I. Holographic and homographic approaches to solve a subsurface radiosounding problem. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 86-99. Subsurface sounding radars are intended for monitoring of hide objects such as subsurface communications, local heterogeneities in soil, leakages from underground fuel storages etc. Radiosounding radars use essentially short-pulsed super-high-band signals, which propagate within media with high degree of attenuation and dispersion. Radio-holographic and spatially-spectral approaches are considered for various kinds of search objects. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Eliseev A. M. A technique of trajectory computation for an object based on a region map taking into account flexible terminal conditions. Aerospace MAI Journal, 2003, vol. 10, no 2, pp. 80-85. A maneuvering problem is considered for an object moving in some media. One of tasks related to this problem is generation of an object trajectory interpreted as a route on a map. A technique is offered to improve a process of trajectory selection. The technique takes into account dynamical properties of the moving object in particular its non-zero response time. Such approach allows to reduce essentially a number of alternative trajectories as well as time needed to select the trajectory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parafes S. G. A solving of vehicle structure design problems by using of identification techniques. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 3-8. Some identification-based approaches are studied to design aircraft structures. Identification algorithms used to solve this problem are based on a special criterion and on corresponding identification techniques including optimization ones. An analyzed structure is compared with reference one. The reference structure is selected to meet needed design goals. A unified approach is used to solve various king of structure design problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grishanina T. V., Savoushkina A. Y. Flutter of all-moving horizontal stabilizer with unilateral links. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 9-13. It is suggested to embed an elastic unilateral tie in control chain for turning an aircraft horizontal stabilizer. This elastic tie implemented as a support or a stretched only cable increases a critical flutter speed value for the stabilizer. A numerical solution are obtained for a case of non-linear aero elastic vibrations of the turned stabilizer. This solution shows significant increasing of the critical flutter speed right up to flutter elimination for some ranges of flight speeds and altitudes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Frolov A. S., Khalenkov M. A. Nonlinear aerodynamic characteristics of an airplane and their influence on loading of horizontal tail unit during pitch maneuvering. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 14-21. Comparative numerical analysis is carried out for some cases of transport-class airplane horizontal tail loading during pitch maneuvers. An influence of aerodynamic data non-linearity and control laws on the loading is considered. As follows from obtained numerical results, external forces and moments computation based on linear aerodynamic theory leads to essential error in horizontal tail load values as well as in airplane motion kinematic parameter values. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kraev V. M. Experimental investigations of turbulent flow structure for hydrodynamically nonstationary conditions. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 22-29. Measurement techniques are devised to study unsteady isothermal and nonisothermal gas flows in a tube. Based on these techniques some experimental data are obtained for profiles of longitudinal and radial velocity components. It is ascertained that an axial velocity structure reorganization takes place within unsteady gas flows in tubes. This reorganization is realized mainly in some intermediate zone within the flow determined with such condition as y/R= 0,05 .. 0,4, where y is a distance from the tube wall, R is the tube radius. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lebedev V. A., Sirotin N. N. An influence of interconnections between processes of gas turbine engines design, manufacturing and maintenance on effectiveness of their use. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 30-38. A problem of application effectiveness increasing is studied for gas turbine engines. An approach offered is based on taking into account interconnections between designing, manufacturing and maintenance of these engines. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isachenkov E. I., Prokopenko A. V. An advanced technology for manufacturing of high-pressure integrated capillar vessels. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 39-43. A new approach is offered to forming thick-walled tubes and high-pressure integrated capillar vessels. This approach is based on plastic working (elasto-plastic deforming) for metal pipes and vessels. The most important area of usage for the approach offered includes devices for safe storage of particularly dangerous explosive substances especially hydrogen. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churkina T. E. About motion of charged particle in a wave field. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. . A stability problem is considered for a case of charged particle motion in a wave packet field. The packet consists of two sinusoidal waves moved with various speeds. At the same time the waves have slightly different amplitudes. Liapunov stability conditions as well as spinning and oscillation instability ones are obtained. These conditions depend on expression kind for the mean angular rotation speed and frequency, respectively. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Chudinov P. S. The optimal throw angle for a mass point moved in an environment with a quadratic drag law. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 50-54. The optimal throw angle for a mass point is sought for a case of motion in an environment with a quadratic drag law. An equation is derived to compute an approximate value of the throw angle. Following optimal throw angle calculation values of eight basic parameters are founded analytically. Then these parameters are used for analytic designing of six main functional dependencies for the problem discussed. An example is given to demonstrate features of the technique offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Tyutyunnikov N. P., Shalashilin V. I. An algorithm to solve some symmetric eigenvalue problem. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 55-61. A new algorithm is suggested to solve classical eigenvalue problem for a real symmetric matrix. The algorithm is based on solving of recurrent sequence of reduced problems with increasing order. A reduction basis used in the algorithm is generated for each subsequent problem within the sequence based on proper basis of preceding problem in the same sequence by means of addition of a new basic vector to it. Features of the algorithm are considered for a case of multiple roots. The algorithm offered is compared with some other algorithms for the same problem. According test results the algorithm offered is worse slightly in comparison with the QR- algorithm, but more suitable for parallel computation processes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoilenko M. V. An identification of observed object by using its image and related trajectory measurements with probability characterized marks. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 62-66. An identification problem is considered for observed object solved by using its image and related trajectory measurements with probability characterized marks. Expressions are derived for posterior probabilities of possible hypothesis about observed object identity as well as for performance index to estimate degree of proximity for the observed image and for some reference one. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yudin V. N. Object secrecy from supervision facilities. Secrecy for presence of an object . Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 67-75. A problem of object secrecy from supervision facilities is considered. A structural object secrecy description is introduced as well as its quantitative description based on entropic indices. Conditions are derived for optimal concealment of the object presence fact. Possibilities are estimated to implement these conditions by means of various disturbances acting upon supervision facilities. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Golubev I. S., Levochkin S. В. A human capital as a basic element causes development of new technical systems. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 76-81. An increasing role of scientific and technological advance is analyzed as an evolution factor for complex systems including weapon systems. One of the most critical factors of such advance is a human capital interpreted as some results of human intellectual activities directed to enhance technical, economical and ecological level of systems developed. An approach is offered for estimation of the human capital as applied to complex system development processes. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Dubenets S. A., Zinchuk A. A., Tkach V. V. Solution analysis for a problem of contaminated soil cleaning. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 82-90. Problems related to design of industrial-level contaminated soil cleaning plants are considered. The contamination sources discussed include various activities with oil production, transmission and transportation. An analysis is carried out to estimate qualitative and quantitative characteristics of contaminated soil cleaning processes. An industrial plant scheme is proposed for two-stage cleaning technology based on sublimation and afterburning processes. An industrial plant scheme is proposed for two-stage cleaning technology based on sublimation and afterburning processes. A scheme, structure and parameters are chosen for a model cleaning plant with low-level output. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Gorbunov G. L. Approaches to optimization of assortment portfolio. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 91-99. A possibility is considered to optimize an assortment portfolio for a manufacturer with a production nomenclature consists of technologically similar units. A problem corresponding to this situation is stated in terms of qualitative and quantitative features of the production nomenclature units as well as prices for these units. Some optimal balance between market requirements and manufacturer capabilities is calculated to maximize investment return on a laid-down capital. This approach allows to reduce a pay-back period for an investment owned capital. Additional resources do not needed in such a case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Volov V. T. Informational and thermodynamical simulation of a spatially continuous economic structure. Aerospace MAI Journal, 2003, vol. 10, no 1, pp. 100-103. A synthetic technique is offered to analyze and control spatially continuous economic structures. The technique is based on gradient-convergent laws for economic variables as well as on a new relationship for conditional entropy used to describe distribution of these variables. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Turkin I. K., Safronov V. S. Investigation of safety factor influence on structure reliability at vehicle forced tests of composite material structures. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 3-6. Safety factor influence upon a flight vehicle composite structural elements reliability is studied for forced tests. Analytic relationships between structure part reliability and test weighting coefficient, assurance factor, number of damage-free tests are derived. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Avkhimovich B. M. Application of the temperature equivalence principle for design of heat engineering systems with variable composition. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 7-12. Design algorithms are obtained for heat engineering systems and heat-loaded vehicle structures. These algorithms based on the temperature equivalence principle allow to develop a set of heat engineering system versions which are equivalent according to non-stationary temperatures of their elements. A special case of the temperature equivalence principle named as instant temperature equivalence is used for this purpose. Besides, a controlled temperature equivalence principle is proposed, which is a generalization of the temperature equivalence principle and provides a generation of a broader set of design versions for heat-loaded vehicle structures. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pismenny V. L. About effectiveness evaluation of turbo-jet engines. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 13-18. A comparative effectiveness analysis is carried out for two gas-dynamic turbo-jet schemes namely for double-chamber turbo-jet schemes namely for double-chamber turbo-jet and for bypass reheated turbo-jet. The analysis is performed for a multiple-mode supersonic aircraft case. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ovsiannikov B. V., Shapiro A. S., Bobkov A. V., Zhdanov I. L. Head pressure enhancement of rotary and disk pumps for flying vehicles. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 19-22. A problem of head pressure enhancement for rotary and disk pumps is very important for design of aerospace vehicle fuel systems. Theoretical abd experimental investigation is carried out to solve this problem. Main results obtained is analysed and discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ones I. V. Theoretical foundations of thermochemical conversion processes for hydrocarbon fuel combustion. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 23-27. An approach is offered to enhance effectiveness of devices including internal-combustion engines which use combustion processes for oil and gas hydrocarbon fuels. This approach is based on using of exhaust gas thermal energy to convert chemically some portions of exhaust gas and fuel into a new kind of fuel. The converted fuel is burned with clarification more than for initial fuel reagent. The developed approach allows to decrease total fuel consumption for devices of the class considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Sergienko A. A., Soun Sing Dong .. .., Martynenko S. I. A mathematical model for steady cavitational fluid flow in divergent nozzle. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 28-33. Some mathematical models are presented for viscous fluid flows in axisymmetrical channels with complicated shapes. The models differ in their complexity level. Assumptions are considered to simplify these flow models. Comparative analyses are carried out for various computational algorithm features caused with coordinate transformations, grid generations, sampling and solving of linearized multigrid equations. A detailed description of used computational algorithms is given. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Isachenkov E. I., Stepanov A. V. A method for hydrogen and other gas mediums tankage. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 34-37. A technique is developed to tank safely hydrogen and other gas mediums. A vessel is designed to realize the technique. Theoretical and application foundations are offered to design structure and manufacturing processes for high-pressure and superhigh-pressure capillary vessels intended for safe tankage and using of hydrogen and other gas mediums. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kniazev A. V. Graph theory based simulation for informational processes in automated testing systems. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 38-43. A distributed data processing is one of major ways to enhance effectiveness and responsiveness of automated testing systems intended to aerospace vehicles as members of complex dynamical system class. This processing includes such elements as generation, transmission, conversion, storage, manipulation and representation of information. A graph theory based model is considered to describe information processing implemented with automated testing system during tests of complex dynamical object. An effectiveness of the testing system is offered to measure by means of metric properties of pseudo-symmetrical graphs. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Rybakov V. V. Single and multiple ionization degree of gas and mixtures. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 44-50. It is required to know plasma analysis, iconicity and thermodynamic functions at prescribed temperature to solve problems associated with physical processes in electric jet propulsion as well as in plasma plant. Single and multiple iconicity for various gases and mixtures are considered. These matters are examined poorly in available sources especially for the mixture iconicity case. An attempt is made in the article to find suitable data. Investigations are undertaken for the equilibrium plasma case without consideration of plasma electromagnetic field and radiation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lianzberg V. P., Shalashilin V. I. High-pressure illuminators with disk-formed translucent element made from nonorganic glass. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 51-56. A problem of load-carrying ability enhancement is considered for high-pressure illuminators with disk-formed translucent element made from non-organic glass. A survey of similar research is carried out based on analysis of developed structures for the illuminators. Ways are offered to improve illuminator strength by means of structural modifications. Experimental results obtained demonstrate illuminator strength enhancement due to these modifications twice or more approximately. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Beliaevsky A. N., Gontsova L. G. An experimental investigation of hydrodynamic properties for scaled-down fuselage model in case of land basing aircraft at emergency water landing. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 57-65. An investigation is carried out in the TsAGI experimental tank to analyse hydrodynamic properties for scaled-down fuselage model in case of land basing aircraft at emergency water landing with gliding. It is shown that under streamlined flow a model lift at Froude number more than three or four becomes negative. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pokalov V. A., Rudenko E. A. A state prediction for discrete nonlinear stochastic systems with a fixed advance. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 66-74. A state prediction problem is considered for nonlinear stochastic systems with a fixed advance. An algorithm is derived to syntheses some finite-dimensional predictor with optimal structure. Gaussian approximation for a distribution function is used to construct predictor algorithm and its computer-based realization. A comparative precision analysis is performed for the Gaussian optimal-structure predictor and for the Gaussian absolutely optimal predictor based on some model problem. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pilishkin V. N. A synthesis of homogeneous robust control systems by means of reduction to integral surfaces. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 75-82. A state constrained problem for a dynamical object is considered. A new synthesis approach is offered based on using of temporary integral surfaces. These surfaces are used to generate scalar reduced motion. The motion allows determining immediately conditions to satisfy state constraints. An algebraic criteria is derived for a homogeneous dynamical system class which determines necessary and sufficient conditions for problem solvability. Some realizations are discussed for the approach discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Pavlova N. V., Sergeychik V. V., Bachkovsky S. V., Smirnova M. A. Modern and advanced avionics simulation tools. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 83-92. Software tools are offered for modern and advanced avionics simulation. The tools to use large heterogeneous data sets as input, intermediate and output information as well as to visualize equipment structure and modeling results during design process. These tools are constructed with object-oriented technology. The source code is written in C++ programming language for Microsoft Windows operating system using MFC library. A set of the software application examples and recommendations are also provided. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakalov V. P., Kutsevol L. N., Novokshanov O. N. On reconstruction of image distorted by convolution with unknown function. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 93-96. An effectiveness of gradient nonlinear optimization technique is demonstrated to develop algorithms for reconstruction of image distorted by a convolution with unknown function. Parameters are found for the algorithms to improve reconstruction quality as well as to decrease image processing time in comparison with traditional approaches. Some results of reconstruction of image distorted by actual device are given. The results prove efficiency of the algorithms suggested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nekrasov A. G. A logistical chain management for resource deliveries in aviation industry. Aerospace MAI Journal, 2002, vol. 9, no 2, pp. 97-100. An urgent problem is considered which consists in integrated logistics usage for delivery management in aviation industry. A special attention is attended to application of the SPEC 2000 international standards for electronic commerce. These measures allow to gain competitive ability of enterprises particularly as regards quality and safety of shipped vehicles and equipment, logistical support and repair of airships, both for national and international air service market requirements. An approach offered is based on logistical and air service chains. It will promote to ensure national security of the Russian Federation as well as to enhance competitive ability of domestic-made airships. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Svirshchevsky S. B., Artamonova L. G., Radtsig A. N., Semenchikov N. V. Spatial vortex-separation structure and airplane lifting surface interaction control. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 3-24. Experimental investigations of composite spatial separation flows in leeward and upper parts of airfoils, wings and systems of wings at low and high attack angles have been carried out in subsonic wind tunnels at the MAI. Wide application feasibility is shown for span-wise baffles to control flow separation and increase lift properties of various configurations. Spatial structure examination of flow around tandem scheme has shown the configuration of baseline wing with a forward horizontal tail can be efficiently used for favorable interference in vortex systems, i.e. to increase lift of the configurations and to decrease airframe acoustic load. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Polkovnikov V. A. Actuator parametric synthesis for aircraft hydraulic steering gear with rate delivery control. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 25-34. Design expressions are obtained for parametric synthesis of hydraulic servo actuators under speed delivery control. Total actuator power is used as the criterion to be minimized. The design expressions are based on the theory of dynamic capabilities maximization for servo drives. An arbitrary and harmonic object motion control laws are considered. Principal limitations for servo actuator energy channel are taken into account. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Mitrofanov O. V. Composite material wing panel of minimal mass design considering supercritical skin response. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 35-42. An approach is offered to design a multiple-closed wing torsion box. The approach is based on the theory of supercritical condition for composite material panels. It intends for development of wing torsion boxes considering various kinds of damage action upon the composite material skin. Design methodology also proposed for orthotropic panels under the influence of biaxial compression as well as for anisotropic panels due to combined loading taking into consideration panel supercritical behavior. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Degtyarev A. A., Kolotnikov M. E., Kul'chikhin V. G., Leontiev M. K., Nekrasov S. S. Vibration diagnostics of maintenance condition of gas-turbine engine used in gas-compressor. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 43-50. Gas-compressor turbine vibration monitoring hardware and software is under consideration for GPA-C16 unit used at TjumenTransgas enterprise. Basic principles and requirements are analyzed with respect to gas-turbine engine condition monitoring, hardware and software tools. Monitoring results obtained for several years demonstrate effectiveness of the tools offered to monitor maintenance condition of the gas turbine unit. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Khaustov A. I., Zhdanov I. L. Peripheral pump application in flying vehicle engine feed system. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 51-58. It stands for reason to use a peripheral pump in flight vehicle engine feed system. Comparative analysis is carried out for modern models of fluid flows within peripheral pump as well as for power transfer from rotor to fluid. Idealized and realistic flow patterns are considered for peripheral pump channels. Original theoretical model is offered to describe fluid flow in peripheral pump channel as well as a physical model of fluid flow. Pump design recommendations are formulated to improve head pressure and power. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zvonarev S. L., Ivanov A. V. Gas-turbine engine gear oil pump vibration diagnostics. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 59-65. A mathematical model is proposed for vibration diagnostics of friction bearing wear-out degree. The bearing supports driving and driven gears of gear-type oil-pump used in gas-turbine engine. Diagnostic indicators are extracted for some specific cases. Results of numerical analysis are discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Vorobey V. V., Loginov V. E. A modern approach to composite material structures design. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 66-72. Composites open up possibilities to realize essentially new design solutions and manufacturing processes. Distinctive feature of composite material parts manufacturing consist in both the part and composite material are formed simultaneously in most cases. The part is formed at once with required shape and dimensions. Consequently, the cost is reduced significantly as compared to production from traditional materials in spite of polymeric couplers and fiber fillers high prices. In contrast to metalworking production engineering, composite material parts manufacturing enhances material recovery to 0.8 — 0.95, whereas effort reduces by factor 1,5 — 2,5. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Morozov N. I., Tiumentsev Y. V., Yakovenko A. V. A controlled object dynamical properties adjustment using artificial neural network. Aerospace MAI Journal, 2002, vol. 9, no 1, pp. 73-94. Artificial neural network (ANN) capabilities are analyzed for some problems associated with aircraft motion control. A compact and effective representation is built for nonlinear aircraft motion model using ANN. The representation is used to adjust dynamical properties for aircraft considered as controlled object. Desired aircraft properties are described by nonlinear reference model. Adjusting controller is synthesized to minimize the difference between the controlled system (control object + adjusting controller) behavior and the reference model. An approach offered is tested computationally by solving the longitudinal short-period aircraft motion control problem. Results obtained demonstrate high efficiency of the approach. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parafes S. G. A technique of structural design optimization for flying vehicle considering control system. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 3-10. A technique is offered to optimize structural design for flying vehicle into account control system. This technique uses a model of elastic dynamical system as a reference one. The reference model describes optimal mass and stiffness distributions for vehicle airframe units based on functional constraints due to interference of vehicle structure and control system. The technique offered is tested by solving structural optimization problem for unmanned airborne vehicle with aerodynamic controls. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Demidov A. S. Structural materials long-term strength prediction. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 11-16. A possibility to predict long-term strength of steel and cast iron samples is analyzed. The samples are exposed to high-temperature damage-terminated tests with duration from 500 to 2000 hours. It is proposed to select samples with respect to internal friction index before testing. Maximum durability is expected for samples with lowest logarithmic decrement of oscillations and brittle fracture. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zakharov S. A., Gilevich D. D., Kul'chikhin V. G., Garanin I. V. Aircraft unlinked piston engine design. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 17-21. Aircraft unlinked reciprocating engine design results are considered. Design alternatives are analyzed with respect to mass decreasing, reliability and effectiveness improvement. Gas generator to compressor power ratio is optimized with respect to engine output. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Kharin A. A., Yanovsky L. S., Shevchenko I. V. Carbon scurf removing techniques for fuel system tubes of gas-turbine engines. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 22-25. There is a necessity to remove carbon scurf arising during gas-turbine maintenance from fuel manifolds as well as fuel-air and fuel-oil heat exchanger tubes. Physical-chemical and chemical-thermal techniques are investigated to solve the carbon scurf removal problem. An approach is offered based on ozone application. This approach consists in ozone adding to coke unsaturated fragments to generate ozonide. Then ozonide is dissolved by an appropriate dissolvent and aqueous solution of non-organic matters. The technique was tested for injector cavities of gas-turbine engine fuel manifold. Test results demonstrate high efficiency of approach offered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Maksimenko A. I. An influence of assembly manufacturing parameters on operational reliability for complex systems. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 26-29. Vibrations of engines and power plants effect deleteriously on quality of the product. Vibrations monitoring and management appear to be possible only when vibration source and level rise conditions are known. It is necessary therefore to revise existing approach to rotor balancing process as the main tool for vibration level decreasing. An alternative approach is offered to combined investigation of processes related to manufacturing, assembling and balancing of rotors. This approach bases on vibration level function as performance index for optimization. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Makhrov V. P. Research into flows with negative cavity numbers. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 30-39. A generation of cavity flow behind axial - symmetric body is analyzed. The flow with negative cavity number is generated by means of hydrodynamic singularity in the form of ring-type wing (the Lighthill-Shoushpanov flow). Theoretical solutions are offered for this problem. An approach is considered to select design parameters for wing cavity generation system. Such an approach provides a real-world problem solving. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Danilin A. N., Volkov-Bogorodsky D. B. On implicit methods for integration of parameterized equations of nonlinear dynamic system. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 40-52. It is possible to develop simple and effective implicit numerical step-by-step integration procedure to solve nonlinear second-order ordinary differential equations with respect to the length of integral curve. This procedure does not contain time-consuming iterative processes. An implicit algorithm proposed bases on the linear acceleration scheme with simple iterations only. Unique existence theorems for equation solution are proved as well as convergence conditions for corresponding iterative process. The technique offered can be applied to nonlinear dynamical simulation for strained systems. An example problem is considered for highly nonlinear strain of elastic flexible cantilever bar. The bar is coiled into a ring initially due to external bending moment. The problem is stated in finite-element form and it is solved using the best parameterization procedure. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Churkin V. M. Dynamical analysis of wind-plane class parachute-cable system. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 53-60. A vertical-plane motion is considered for wind-plane class parachute-cable system. This system is composed from two parachutes linked with a long elastic cable. An approach is offered to solve linear and nonlinear problems associated with parachute-cable system dynamics. This approach bases on Birkhoff-Schlesinger-Tamarkin (BST) technique. Asymptotic presentation of partial solutions is generated due to BST linear analysis for linearized cable equations of motion. Natural cable oscillation modes computed with BST technique are used as coordinate functions for Bubnov-Galerkin technique during nonlinear dynamical analysis of the parachute-cable system. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bondarev B. V. Quantum Markovian kinetic equation for a system of identical particles. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 61-64. Lindblad equation is considered for random Markovian process in open quantum system. Kinetic equation is derived to describe evolution for the system of identical particles. Integral equations are defined for a function of particle state distribution as applied to a case of thermodynamic equilibrium of a many-particle system. It is shown the equations lead to Fermi-Dirac and Bose-Einstein distribution functions for a system of non-interactive particles. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Orlov M. S., Souslov L. L. Ground-based stationary objects positioning in earth observation radar at flat tilt. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 65-68. A mathematical model is derived for airborne earth observation radar coverage, image, and ground-based objects precise positioning with respect to the carrier. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Samoilenko M. V. Aerodynamic object attitude definition with respect to trajectory parameters. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 69-74. A method is offered to estimate trajectory parameters influence upon the attitude of an aerodynamic object. The technique is based on minimization of mean square differences over n subsequent attitude estimations, packed out from radar and optical channel, with respect to unknown parameters of the model. It is shown the probabilistic criteria appear equivalent to minimum mean square vector difference of n attitude estimations according to registration channel functioning principles. The model is linearized with respect to its parameters. This technique allows using pseudo inversion of matrix to solve the problem. Mathematical expression is obtained to compute estimations of model parameters. An algorithm is offered for implementation of estimation process. The algorithm consists of one step and estimates for n samples simultaneously. The model is ready to use for various radar signal processing problems. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Merkishin G. V., Slivin I. V. Optoelectronic altimeter for aircraft landing system. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 75-82. Various photo receiver schemes are estimated for a precision altimeter. Precise altitude measurements over the runway are called for thrust reversal optimization. The optoelectronic altimeter offered can be applied either on a VTOL aircraft of the 5-th generation, or on a shipboard helicopter landing on pitching and rolling carrier. Some variants are analyzed for automatic gain control and photo receiver schemes. Noise level estimated for the system considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A method to estimate transportation efficiency in air enterprise, airline and leasing company network. Aerospace MAI Journal, 2001, vol. 8, no 2, pp. 83-89. A technique is offered to appraise airline efficiency considering aircraft leasing. Detailed analysis of airline charge is carried out for specific flights. The method offered approves effectiveness of investments. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bokov K. K., Verkholomov V. K., Kryuchkov V. P. Aircraft gas turbine test bed. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 3-6. A structural scheme is considered for a bench to test aircraft gas turbine engines. The characteristic feature for this test bench is slotted flat-formed ring nozzle with toroidal ring jet. The nozzle is link with embedded pipeline by means of elastic elements. This approach makes possible to eliminate intake air impulse, therefore to increase significantly characteristics measurement precision for aircraft engine tested. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ravikovich Y. A., Savin L. A. Axially lubricated radial multilobe journal bearing design. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 7-16. A mathematical model for multilobe journal bearing with axial lubrication is discussed. An approach is offered to consider complex configuration of the bearing radial clearance by differential equations solving. The proposed model takes into account impact of lubrication boiling, film turbulence, compressibility upon pressure field formation. Computation of the pressure field in lubrication layer as well as computation of carrying capacity and power losses caused by friction is presented. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Abdullin I. S., Ghaliaoutdinov R. T., Kashapov N. F. Synthesis of thin film coatings with controlled high-frequency dielectric constant. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 17-24. A thin film coating with controlled dielectric constant synthesis is considered. The problem is solved using low-pressure jet inductive coupled plasma torch. The approach based on variation of high-frequency dielectric constant complex part allows to get zero reflection from a high-reflecting single-layer coating surface at a specified frequency of electromagnetic radiation. Efficiency of the method is demonstrated for aluminum mirrors with reflection factor about 90 per cent. Proposals are given for interference system design and implementation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Zubov A. G. Synthesis of self-organizing stochastic system with active parametric adaptation. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 25-32. Synthesis of self-organizing stochastic system with active parametric adaptation is under consideration. Suggested optimization concept is based on combined use of dynamical programming method, information coordinates approach and sensitivity theory. Analytical solution of the problem is obtained. A moving object terminal control synthesis example is considered. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Shamrikov B. M., Maksin D. G. Penalty function definition for parametric identification on a finite sample. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 33-38. A formalized procedure to define a performance index for parametric identification on a low number of observations is obtained. The procedure uses algebraic identification theory based on the generalized least-squares method. The performance index is formed using ortogonalization. Parametric identification algorithm offered solves the problem on a single finite sample at restricted a-priory information in a real time mode. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voronin E. N., Emel'yantsev O. A. Electromagnetic-holographic imaging with mathematical aperture synthesis. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 39-47. Wave data acquisition and processing techniques are suggested to increase resolution of electromagnetic holographic imaging. The techniques take into account priory data about geometric symmetry and localization of an object imaged. It is shown the holographic reconstruction root-mean-square can be improved by using of axial, translational, central and other kinds of the symmetry for current electromagnetic wave situation. An approach to aperture mathematical synthesis is suggested and analysed based on priory information about spatial localization of objects imaged. An interpretation of the approach is presented from physical point of view; its ultimate capabilities are evaluated. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voskresenskii D. I., Evstropov G. A., Smirnov S. A. Computation of optimal field distribution in antenna aperture with minimal concentration area at specified concentration factor. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 48-52. The load power of a radar appears to be proportion to the antenna concentration factor in several radar types, e.g. in environmental radar. The radar angular resolution depends on the concentration angle. A problem of field distribution in antenna aperture is to provide minimal concentration angle at specified concentration factor. The problem is solved using partial diagram technique, Lagrange multipliers method as well as implicit function approach. Collinear array, linear antenna, and circular aperture antenna cases are considered. The result obtained appears to be suitable for antennas with either rectangular, or circular aperture. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Grinev A. Y., Bagno D. V. Hybrid multi-functional optoelectronic processor of space-time signals. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 53-63. Methods, algorithms, structural arrangement and elementary unit basis are developed and investigated for a hybrid optoelectronic processor of complex space-time radio signals. The processor, combined with a multi-channel receiving antenna array, supports panoramic radio scene survey, adaptive rejection of space jam down to 20-25 dB, complex signals spectral and correlation analysis, demodulation, signal structure recovery and receiver diagnostics. A prototype processor was tested in on-ground telemetry data system. Results obtained agree to theoretical model. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Erokhin M. Y. Tracking signal correction in synthetic-aperture radar at uncontrolled ranging error. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 64-67. The origin of uncontrolled quadratic phase initiation in synthetic-aperture radar (SAR) image is under consideration. An algorithm is offered to recover the image at uncontrolled ranging error. The algorithm is based on mathematical programming. A quality level of image recovery is analyzed. Some examples of reconstruction of the SAR image digital model are discussed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Yazev P. M. Effectiveness evaluation for multipath mitigation by special strobe sequences in satellite radio-navigation system receiver. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 68-73. An approach is offered to evaluate effectiveness of multipath mitigation in pseudo-noise signal time delay tracking system. The approach uses special strobe sequence as the correlator reference clock. The problem is solved by multipath error control computation when a set of distributed reflectors exist. Recommendations are given to choose strobe sequence parameters. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bratchikov A. N., Gordeichuk D. V., Orlov A. P. Optical techniques to control a phased array antenna. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 74-82. Current status and perspectives for active phased array antenna control using fiber-optic and optoelectronic technologies are discussed. The antenna array considered is designed to radiate electromagnetic waves in super-high frequency (SHF) and millimeter wave bands. Two approaches are considered for phased array antenna control. The first approach is based on optical technique implementing traditional method of optical aperture generation using controlled optical time-delay circuits. Systems caused with the second approach intensively use hybrid coherent optical processors with no necessity to compute, generate and control phase or delay of SHF-signal for each antenna array oscillator in a real time mode. Traditional technique of aperture synthesis by field phasing for each oscillator in phased array antenna is replaced within the second approach by holographic generation of required gain-phase distributions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Bakalov V. P., Novokshanov O. N. A technique of distorted convolution compensation for blind deconvolution problem solving. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 83-86. A possibility is demonstrated to compensate convolution distortions caused with nonlinearity and limited dynamical range of recorder amplitude curve. This approach allows solving the blind deconvolution problem. Distortion compensation technique is offered to have a sufficient recovery quality at a little computer resources (memory and CPU time). The technique is based on generalized approximation of recorder amplitude curve. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ionov V. I., Aleshina O. N. Production quality management optimization for aircraft enterprise. Aerospace MAI Journal, 2001, vol. 8, no 1, pp. 87-94. An approach to optimization of production quality management for aircraft enterprise is presented. Techniques are suggested to solve problems associated with production quality management, optimal scheduling and efficiency increasing for organization and technical quality improving measures. It is shown the mathematical problem statement offered can be expanded by means of involving wider list of technical and economical factors. |
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