Effect of solidity on non-axisymmetric endwall contouring performance in compressor linear cascades

This paper presents both the computational and experimental results to assess the effectiveness of non-axisymmetric endwall contouring in linear cascades under different solidities. Endwalls were designed by geometric scaling of a prior optimized endwall. The results show that the total pressure loss can be reduced by the contoured endwall (CEW) under different solidities. The mechanism of the improvement of CEW is that the adverse pressure gradient (APG) has been reduced mainly through the groove configuration near the leading edge of the suction surface. Besides, the cross-passage pressure gradient (CPG) has also been reduced, which has the benefits to further suppress the corner separation. Moreover, there is an optimum range of the solidity for the CEW. For a lower solidity, the performance of the CEW at +7 degree incidence presents a rapid deterioration, due to the risk of flow separation near the mid-span, for a higher solidity, the profile loss can be more dominant.