Effect of rotating speed ratio on the first rotating stall stage in contra-rotating compressor

Effect of rotating speed ratio on the first rotating stall stage of a Contra-Rotating Axial Compressor (CRAC) which consists of two counter-rotating rotors is investigated numerically. Results obtained indicate that the rotating speed ratio has little impact on the type of stall inception of contra-rotating compressor, and there exists "spike" type stall inception in this CRAC near stall point. Under the condition of rotating speed ratio R₂:R₁ ≥ 0.9, the blade loading of ROT2 is more heavy than that of ROT1, the intensity of the tip leakage is also much more bigger than that of ROT1, the ROT2 is the first rotating stall stage; on the contrary, ROT1 will be the first stall stage.