Effects of Sloped Trench Casing Treatment on Compressor Cascade

A numerical simulation was carried out to investigate the effects of sloped trench casing treatment on the tip leakage flow structure in a compressor cascade. A detailed comparison of leakage flow’s loss, trajectory, size and its interaction with the main - stream, as well as the generation mechanism, was conducted with and without the sloped trench casing treatment. Results show that, with the sloped trench casing treatment, the performance of the cascade has been improved. The secondary flow near the trench results in increased attack angle, strengthened tip clearance jet, and altered tip leakage vortex trajectory. With the sloped trench casing treatment, the generation mechanism is altered. The strength of the tip leakage vortex has weakened and thus improve the performance of the cascade.