A compensation model for the effect of transient processes in the fuel lines of modern aircraft engines


Аuthors

Aslanov A. R.1, Kraev V. M.2*, Myakochin A. S.2**, Seliverstov S. D.2***

1. Joint-Stock Company National Helicopter Center Mil&Kamov , 140070, Lyubertsy, Moscow Region, Russia
2. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: kraevvm@mail.ru
**e-mail: amyakochin@gmail.com
***e-mail: seliverstovsd@mai.ru

Abstract

Civil aviation transport, like no other, is overly sensitive to rising prices for traditional hyd-rocarbon fuels. This dependence is related to the significant fuel component in the cost of air transportation. The aircraft engines designers have been trying to switch to alternative fuels for more than 25 years. Cryogenic aviation fuels were considered among alternative fuels for aircraft engines. These include: liquefied natural gas consisting mainly of methane, liquid hydrogen and cryogenic propane. Cryogenic fuels for aviation have a number of features compared to traditional hydrocarbon-based fuels. From the point of view of ecology, such fuel is a direct competitor to aviation kerosene. In 1998, an aircraft with a liquid hydrogen engine Tu-155 was tested in the Soviet Union, and in 1989, equipment testing and research into cryoplane capabilities using liquefied natural gas Tu-156 began. Previous results show a significant increase in the coefficients of heat transfer and hydraulic resistance at the time the engine was switched from idle into take-off mode. The reason for this change is the restructuring of the turbulent flow structure in hydrodynamically unsteady conditions. The heat transfer coefficient can exceed the values calculated from stationary dependences by more than 2 times, and the coefficient of hydraulic resistance by more than 3 times. This difference leads to significant disruptions in the operation of the entire cryogenic fuel system, and may lead to operational failures. In real engines, switching from taxi mode to take-off mode increases fuel consumption up to 10 times in a few seconds, which is a significantly unsteady process not only for the engine itself, but also for the entire fuel system. The authors have identified the effect of possible cold boiling of cryogenic fuel in fuel lines with a sharp increase in hydraulic resistance and confirmed the unacceptability of using a quasi-steady approach to calculate non-stationary processes in the fuel lines of modern aircraft engines.
The proposed model for compensating the effects of transients is suitable for practical calculations in the fuel systems of modern gas-turbine engines operating on cryogenic fuel. Further research in the field of unsteady flows of cryogenic liquids to create more accurate engineering models.

Keywords:

aviation gas turbine engines, cryogenic fuel, unsteady processes, hydrodynamics and heat transfer in channels, cavitation stability

References

  1. Kalinin EK, Dreitser GA. Unsteady convective heat transfer for turbulent flows of gases and liquids in tubes. International Journal of Heat and Mass Transfer. 1985; 28(2):361–369.

  2. Dreitser GA, Bukharkin VB, Kraev VM et al. Experimental study of effect of hydrodynamic unsteadiness on a turbulent gas flow structure and heat transfer. Heat Transfer Research. 1998;3:93.

  3. Popov D.N. On the features of unsteady flows in pipes. Izv. vuzov. Mashinostroenie. 1972;7:78. (In Russ.).

  4. Valueva E.P., Popov V.N. Unsteady turbulent fluid flow in a round tube. Izvestiya Akademii nauk SSSR. Mekhanika zhidkosti i gaza. 1993;(5):150. (In Russ.).

  5. Valueva E.P.. Hydrodynamics and heat transfer during turbulent fluid flow in a pipe under conditions of mono-tonous flow rate change over time. TVT. 2005;43(2): 212–222. (In Russ.).

  6. Aslanov AR, Kraev VM, Molchanov AM. A model for calculating transients in cryogenic fuel lines of modern aircraft engines. Thermal processes in engineering. 2023; 15(4):185–192. (In Russ.).

  7. Dreitser GA, Kraev VM. Turbulent gas flows with hyd-rodynamic instability. Krasnoyarsk: SAA. 2001. 148 p. (In Russ.).

  8. Nikiforov AN, Gerasimov SV. Changing the parameters of the turbulent flow during acceleration and deceleration of the flow. Inzhenerno-fizicheskii zhurnal. 1985;(49(4)): 533–539. (In Russ.).

  9. Liiv UR. On hydraulic patterns in slow motion of fluid in a pressure cylindrical pipeline. Tr. Tallinskogo politekhi, in-ta. 1965;(223):29. (In Russ.).

  10. Liiv UR. On hydraulic patterns during accelerated fluid movement in a pressure cylindrical pipeline. Tr. Tal-linskogo politekhi. in-ta. 1965;(223):43. (In Russ.).

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