Numerical investigation of the flow mechanisms of compressor stall delay through end wall self recirculation

End wall self recirculation is known as an active method to control stall in axial compressors. It is implemented by combining injection and bleed on the compressor shroud and has the characteristic of injection or bleed quantity self adjusting with the compressor work point varying. Effect of end wall self recirculation on the performance of an axial-flow rotor was performed with the help of numerical method. The numerical results show that end wall self recirculation method can not only suspend the stall effectively but also improve the compressor efficiency appreciably. The fundamental flow mechanism of end wall self recirculation reforming the compressor performance was obtained by detailed analyzing the flow fieid at the blade tip.