不同参数端壁翼刀控制二次流机理的实验研究

Experimental Investigation of Endwall Fences with Different Length and Axis Location to Control Secondary Flow in Compressor Cascade

不同周向和轴向位置的压气机叶栅上安装1/2轴向弦长翼刀的叶栅出口流场测量结果表明,两种方案的叶栅总损失随翼刀周向位置变化的总体趋势是翼刀靠近压力面时叶栅总损失降低。翼刀安装在流道前半部的最佳周向位置是距离吸力面60%相对节距处;安装在流道后半部的翼刀最佳周向位置是距离吸力面80%相对节距处。通过对比初步探讨了翼刀减小二次流损失的机理:一方面通过降低流道内端壁附面层内横向压力梯度,减弱低能流体向吸力面/壁角区的堆积;另一方面是通过产生的反向翼刀涡限制马蹄涡的压力面分支发展,从而减小通道涡的尺寸和强度。

The compressor cascade exit flow field with the 1/2B length of endwall fence at different circumference and axis location was surveyed. It was showed that the total cascade loss will be. reduced when the fence position is near the pressure： surface. Tile fence position where the total cascade loss is minimum is 60% T far away from suction surface when the fence is located at the foreside of the passage, and 80% T far away from suction surface when the fence at the pearward of the passage. Through the test results, the principle of endwall fence to control secondary flow is that the flow to suction surface/endwall corner is weakened due to the pressure grads in the cross boundary layer reduced by the fence. On the other hand, the passage vortex is also weakened because the horseshoe vortex is restricted by reverse fence vortex.