Optimal geometric characteristics of slotted finning in freely convective cooling systems

Аuthors

Nikolaeva D. V.^*, Lopatin A. A.^**

Kazan National Research Technical University named after A.N. Tupolev, Kazan, Russia

*e-mail: Dashulkakuku@mail.ru
**e-mail: aalopatin@kai.ru

Abstract

The article presents the results of the heat transfer study of a split rib under natural convection conditions. The purpose of this study is finding the effective ways to intensify heat transfer in the systems of electric power and radio-electronic equipment and determining optimal parameters of these devices operation. To achieve the goal, a number of tasks were formulated. These tasks include: developing of experimental test bench and methods for measurements conducting; performing a series of experiments. They also include the study of the initial air parameters and geometry of the rib, the effect of constraints stringency on the intensity of heat transfer; basic measurements errors determining; obtaining criterion dependencies for the heat transfer coefficient and Nusselt number computing. A series of experiments were conducted, which results allowed obtain an algorithm for determining and computing the main characteristics of the heat transfer process. The obtained experimental values deviation from the calculation performed according to the dependences of M. Mikheev and V. Isachenko dependencies did not exceed 6%. The conditions stringency factor, as well as of the optimal opening angle of the ribs determination, effect positively the process of heat transfer intensification. The heat transfer maximum was obtained at the casing rise of 40 mm within the range of 10 mm to 100 mm and the ribs opening angle of 30 degrees within the operating range of 10-60 degrees. Analysis of the flow under study in the area of laminar flow regime was performed in the course of this work. Criterion dependencies for heat transfer coefficient and Nusselt number computing were obtained. The heat transfer coefficient of the split rib is 2.3-4 times greater on the average, than this of the smooth rib.

Keywords:

split rib, heat transfer, convection, intensification

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