Mechanism Study of End-Wall Fillet's Influence on Performance and Flow Field of High-Load Compressor Cascade

For the purpose of improving compressor's flow condition in end-wall region and reducing flow loss, five different fillet structures around blade root were designed on a large-scale low speed compressor cascade, which was investigated by full 3D numerical simulation of Numeca. Results show that the highest loss reduction reached up to 5.22% on original cascade's stall condition, while the loss increased by 1.12% on design point. For the best case, the mechanism of improvement on performance and flow field was analyzed, and the reason that the other four structures made little promotion was given. With the fillet, the cascade reduced the stall factor by 41.29% and could adapt a larger range of incidence angle. The flow separation on suction side near the end-wall is evidently restrained and the strength of horse-shoe vortex and reverse flow region are diminished. Moreover, the outlet flow becomes more uniform and secondary flow energy decreased. Finally, both the total loss and the corner flow are significantly improved.