Rotating stall mechanism of dual-stage contra-rotating compressor

Based on steady numerical simulation of contra-rotating compressor in lab, a numerical investigation of the rotating stall mechanism of a contra-rotating axial flow compressor was conducted. The study shows that: (1) the rotating stall inception which appears near the stall point is "spike" type; (2) the tip clearance vortex in rotor 2 develops rapidly near the stall point and the passage is chocked, which cause the instability of the whole compressor; (3) the aerodynamic stability of compressor is determined by the development of tip clearance vortex in rotor 2 because of the high loading on the blades.