A numerical simulation was carried out to investigate the effect of the moving endwall on the tip leakage flow structure in a compressor cascade with different tip clearances. A detailed comparison of leakage flows loss

trajectory

size and mass flow rate

as well as the tip leakage flow features and its interaction with the mainstream

was conducted. Results showed that the moving endwall led to more leakage mass flow through the gap. The region of the tip leakage vortex was flattened away from the blade suction side. The interaction between the mainstream and the tip leakage flow was weakened. The structure of the vortexes inside the passage was altered. In the small clearance cases

the main effects of the moving endwall were focused on the near wall region. While in the large clearance cases

the moving endwall clearly suppressed the tip separation vortex

thus influencing the velocity distribution of the whole clearance

and further impacting the shear between the mainstream and the tip leakage flow.