Stall of an axial-compressor rotor with casing treatment

For investigating the stall of compressor with casing treatment, using the unsteady Relynold averaged numerical simulation method, numerical simulations of an axial transonic rotor with a axial skewed slot casing treatment with back plenum were carried out. Then, the rotor characteristics at high/low speed were gained, accordingly, the flow fields at near stall points were analyzed as well. It was found that the main responsibility of the inception of stall under the condition of casing treatment is different from the condition of the solid casing. At the operation point of stall, due to that the casing treatment could not absorb any more low energy fluid at blade tip, the fluid with little streamwise momentum was accumulated near the trailing edge of suction surface at blade tip, and a serious flow blockage was formed, the stall was finally triggered, even though the negative influence of the blade tip leakage flow was still suppressed effectively.