The effect of dimpled surface on loss reduction and vortices in a highly loaded compressor cascade

This study investigates the influence of geometry parameters of dimples on the blade surface in a high-turning linear compressor cascade. Four arrays of dimples with a depth-to-diameter ratio of 0.25 and the depth varying from 0.1 mm to 0.6 mm in six different configurations were erected to explore their effects on loss coefficients, streamline patterns, topology structure as well as vortex structure. The dimple configurations were evenly distributed among 42–65% axial chord on the suction surface. The Reynolds-averaged Navier–Stokes method was used in the computational investigation under the nominal condition. The results show that the dimples with proper size can positively affect the flow loss and flow pattern. The larger dimples do not dramatically overtake the smaller ones in loss reduction, suggesting that there exists an optimal size of dimples in loss reduction within compressor cascades. The total number of singular points and separation lines in the cascade are both reduced under the dimple con...