Numerical Research on the Impact of Axial Position of Endwall Suction Slot on Tip Leakage Flow

Abstract

In order to reduce the adverse effect of the tip leakage flow of cantilever stator on compressor performance, the impact of the axial position of endwall streamwise suction slot on tip leakage flow was numerically studied. The study on the overall performance of the compressor and the details of the flow field near the stator end region with and without suction showed that all suction schemes could weaken the tip leakage flow intensity to a certain extent, and the flow control effect was gradually enhanced with the increase of the suction flow rate. In the case of small suction flow rate, for example, 0.5%, the short slot schemes can improve the overall efficiency of the compressor by about 0.5%, which is more advantageous than the long slot scheme, and the overall efficiency improvement of the latter is about 0.3%. The advantage of the long slot scheme in flow control is reflected in the case of large suction flow rate, that is, 1.0%, which may improve the overall efficiency of the compressor by about 0.96%. The axial position of suction slot has a significant influence on flow control effect of the tip leakage flow. Compared with the downstream suction, which only modified the flow field by reducing the blocking effect generated by tip flow vortex, the upstream suction could better control the tip leakage flow by restraining the development of the initial stage of the leakage vortex. Besides, the endwall suction scheme with a full chord length slot has the greatest impact on the passage vortex, its effect on modifying the flow field near the end zone was determined by the combinatorial action of the enhancement of the passage vortex and the attenuation of the leakage vortex.