Entropy analysis of a cover-plate pre-swirl system

To find out the real reason of the flow losses in a cover-plate pre-swirl system and provide the optimization method, analysis of the entropy increment and entropy generation in a pre-swirl system was carried out based on the results of 3D aerodynamics computation. The results show that the pre-swirl system achieves the largest temperature-reduction only if the entropy increment is zero, with the parameters of the system inlet and outlet fixed and ignoring the heat transfer between the system and the outside. What is more, the temperature-reduction reduces with the entropy increment enlarging. About 37 percent of the system entropy increment, which is the largest part of all, generated by the supply holes. The entropy generation caused by the turbulent dissipation is two orders of magnitude higher than the one caused by the direct dissipation, and the main reason to cause the entropy generation to be large is the large difference of velocity between the flow and the wall in the inlet of supply holes. © 2016, Editorial Department of Journal of Propulsion Technology. All right reserved.