A parametric investigation of endwall vortex generator jet on the secondary flow control for a high turning compressor cascade

A parametric investigation of secondary flow control using endwall vortex generator jet (VGJ) is performed in a high turning compressor cascade. The mechanisms for the variations of VGJ performance with different jet parameters including the pitch angle, yaw angle and jet-to-inflow total pressure ratio are discussed in detail. And then the potential of VGJ at the off-design points is further validated. The results show that the influence of VGJ on the cascade performance depends on the combination of the loss increase in the upwash region and the loss reduction in the corner region. A jet pointing upstream of the cascade or with too large jet-to-inflow total pressure ratio would enhance the mixing losses in the upwash region remarkably. Whereas a jet with negative yaw angle, too large or too small pitch angle would reduce the effects of VGJ on the endwall cross flow and the low energy fluid accumulation in the corner region due to the weakened reverse vortex. In this work, the optimal performance is obtained by the jet with a pitch angle of 20° and a yaw angle of 0°. For the off-design points, the potential of VGJ on the loss reduction is enhanced with the increase of the incidence. The loss reductions at i=-5° and i=5° are 13.2% and 32.5% respectively, whereas the beneficial effect on the flow turning decreases slightly.