Effects of tip clearance size on the performance and tip leakage vortex in dual-rows counter-rotating compressor

Abstract

Based on the preliminary validation of the numerical results with an experiment, the steady results of different tip clearance size effects on the performance and tip leakage vortex of counter-rotating compressor were discussed. The predicted results showed that the stable margin and isentropic efficiency of the counter-rotating compressor decreased with increasing of the tip clearance size. Furthermore, increasing the tip clearance size had a greater negative effect on the performance of the upstream rotor than the downstream rotor. Detailed flow field analyses further demonstrated that the unstable flow occurred in the two counter-rotating rotors with greater tip clearance size. The rotor downstream was the main unstable factor which caused the counter-rotating compressor to breakdown when a smaller tip clearance size was used.