The rotor blade of an experiment turbine for low Reynolds number flow conditions is recontoured on the hub endwall to reduce the hub’s secondary flow losses. The baseline rotor blade is radially stacked with airfoils of free vortex twisting. The hub section airfoil of the rotor blade is reprofiled for three considerations. The first is to reduce the inlet metal angle to fit with the vane’s exit flow angle near the hub endwall. The second is to reduce the airfoil’s stagger angle to reduce the pitchwise pressure gradient on the hub endwall. The third is to extend the airfoil’s axial chord to a limited distance before the baseline one to build a leading edge fillet. A steady RANS flow computation is carried out to compare the flow fields inside the baseline and the new contoured rotor passages. Flow comparison reveals that the passage vortex intensity is reduced and that the total pressure loss is reduced by 8.9 % in the hub region. The new contoured rotor shows potential application in reducing rotor secondary losses through the stacking of two-dimensional sectional airfoils.

在低雷诺数流量条件下的实验涡轮机转子叶片在轮毂端壁上重新设计轮廓，以减少轮毂的二次流量损失。基线转子叶片沿径向堆叠有自由涡旋扭曲的翼型。出于三个考虑，重新设计了转子叶片的轮毂部分翼型。第一种是减小进口金属角度，使其与轮毂端壁附近叶片的出口流动角度相适应。第二个是减小翼型的交错角，以减小轮毂端壁上的变桨压力梯度。第三是将机翼的轴向弦延伸到基线之前的有限距离，以建立前缘圆角。进行稳定的RANS流量计算，以比较基线和新轮廓转子通道内的流场。流动比较表明，在轮毂区域，通道涡流强度降低，总压力损失降低8.9％。新的轮廓化转子显示出了潜在的应用，通过堆叠二维截面翼型来减少转子的二次损失。