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.