Research on flow separation control for a highly loaded compressor cascade with combined boundary layer suction

In order to study the effectiveness and mechanism in controlling the flow separation for the highly loaded compressor cascade with combined boundary layer suction(BLS), a linear compressor cascade which has separated flows both on the suction surface and in the corner was investigated with experiment and numerical simulation, and three different suction schemes were explored. The results show that BLS can remarkably improve the performance and incidence characteristics of the cascade. The profile loss coefficient of the aspirated cascade is reduced significantly at the incidences from -5° to 8°, and the loss coefficient can be reduced by about 67% at the suction rate of 0.76%. Part blade span suction scheme (SS1) can effectively remove the separation over the suction span resulting in the increase of separation area in the corner. The separated flows both on the suction surface and in the corner are almost completely eliminated by combined suction scheme (CS), therefore, the load and the diffusion capacity over the full span are improved significantly. The change law of the loss coefficient is different with variation of the suction rate combination at different incidences, and it is more effective to reduce the loss of cascade with suction control on suction surface at a high incidence. It is needed to choose the best combination of suction rate according to the incidence when conducting a combined suction.