Enhancing Aerodynamic Performances of Highly Loaded Compressor Cascades via Air Injection

This article experimentally studies the effects of air injection near the blade trailing edge on flow separation and losses in a highly loaded linear compressor cascade. Aerodynamic parameters of eight cascades with different air injection slot configurations are measured by using a five-hole probe at the cascade outlets. Ink-trace flow visualization is performed to obtain the flow details around the air injection slots. The static pressure distribution is clarified with pressure taps on the endwalls. The results indicate that air injection has little effect on the static pressure distribution on the endwalls, but improves the flow behavior at the corners between the suction surfaces and the endwalls with the decrease in losses at midspan. Slot positions have great effect on the compressor cascade performances. The optimal slot location is 25% of the blade span. The energy loss coefficient is reduced by 5.5% at most.