Control of High‐Load Compressor Stator Corner Flow by Blade Slotting

Flow separation often occurs in the stator corner of a compressor, especially in a highly loaded compressor. Therefore, there are multiple methods for flow control, such as blade slotting, which uses the pressure difference between the pressure surface and the suction surface to form a suction surface jet. This paper proposes to slot inside the blade. The slot’s inlet is located at the leading edge of the blade, and its outlet is located on the suction surface. This uses the inlet velocity’s impulse to form a high‐momentum jet to control the suction surface flow. The study shows that the slotted blade can greatly reduce the flow loss in the stator corner and effectively improve the stage efficiency in the working flow rate range of the compressor. In the present study, the stage efficiency is improved by 1.10%. The chordwise position of the slot should change along the direction of blade height, and the slot outlet location should be near the starting point of the separation to achieve the overall improvement of the stator aerodynamic performance. The corner plugging of the slotted stator is reduced, so the static pressure gradient of the rotor outlet along the blade height is increased, and the static pressure of the rotor outlet with the same flow rate is increased. The stall margin is reduced for the compressor stage stall induced by the exit of the shock wave from the blade passage at the rotor tip. In order to avoid the adverse effect of slotting on the stall margin, the static blade tip is swept forward, and the stall margin is improved by 7.77%. The comparison between steady and unsteady computations shows that the stage performance improvement obtained by the stator slot is almost the same.