Temperature drop and output work of radial inflow in rotating cavity with finned vortex reducer

This study aims to investigate the output work and temperature drop in a compressor disk cavity equipped with a Finned Vortex Reducer (FVR) to improve the performance of the secondary air system of gas turbine engines. Based on the experimentally validated simulation results, we explore the effects of the rotating speed of the disk, coolant mass flow rate and the size of the fin on the flow and energy transfer of the radial inflow in the rotating cavity. The results show that the circumferential acceleration of the flow by Coriolis force is inhibited by the radial assembled fins from the rotating coordinate system, forcing the swirl ratio into one in the finned region and resulting in the reduction of the pressure drop. Outside the finned region, the variation characteristics of the swirl ratio follows that of a free vortex, which is typically found in the radial inflow through a simple cavity, i.e., cavity without any vortex reducer. For the output work of the FVR cavity flow, it is mainly caused by the pressure difference on the fin surfaces, while those by the viscous shear force could be neglected. We propose a simplified model to predict the output work and total temperature change in the FVR cavity, which generally matches well with the simulation result. The research findings can provide guidance for the design and optimization of secondary air system in gas turbines.