Effect of endwall SJA on the corner separation of compressor cascade

To address the issue of flow separation in the corner region of an axial flow compressor, an active flow control technique called sweeping jet actuator (SJA) was employed. Unsteady numerical simulations were conducted to investigate the impact of endwall SJA jets on mitigating flow separation in the compressor’s corner region. The effects of SJA placement, jet pressure ratio, jet skew angle, and their influence on flow characteristics were analyzed and discussed. The results indicated that the endwall SJA jets primarily affected the development and migration of the boundary layer on the endwall and blade surfaces. By suppressing the generation and development of concentrated shedding vortices, the corner separation was suppressed and the flow loss in the corner was reduced. Moreover, the optimal configuration for loss reduction was achieved when the SJA was positioned at approximately$ {x}_{\mathrm{S}\mathrm{J}\mathrm{A}}/b $=85% along the axial direction and close to the suction surface. When the jet pressure ratio for the SJA was approximately 1.01, with the help of only 0.03% of the mainstream flow for the jet flow, a relative reduction of 13.4% in total pressure loss coefficient can be achieved. Furthermore, by appropriately designing the jet skew angle, the issue of “sweeping blind spots” in the endwall SJA can be effectively mitigated, leading to further enhancement of the SJA controlling effectiveness.