冲角变化对涡轮叶栅内间隙流动的影响

航空发动机涡轮工作效率的损失很大程度在于涡轮叶尖间隙损失，而叶尖区域泄漏流动的形成机理强烈地依赖于叶栅的运行工况，因此有必要研究来流冲角的变化对涡轮叶栅内间隙流动的影响。为此在低速风洞中对三套不同叶片积迭线形状的矩形叶栅进行了实验，测量了间隙内以及沿流动方向8个横截面的气动参数。通过对实验结果的分析和讨论，认为随着冲角的增加叶顶压差与端壁流道横向压力梯度增大，同时叶栅的总流动损失也随之增加。

Effect of different incidences on turbine cascades flow in blade tip clearance

The turbine operating efficiency of aeroengine was correlated with the blade tip clearance loss, and the forming mechanism of the leakage flow in blade tip region strongly depended on the operating condition of the blade cascades, so it is necessary to investigate the effect of different incidences on clearance flow in turbine cascades. Thereby, experimental investigation was carried out on the low speed linear cascade wind tunnel with three blade cascades that had different blade stack lines, and the aerodynamic parameters on blade tip clearance and eight transverse sections along the flow direction were measured. By analyzing and discussing the test results, the present paper thought that with the increasing of the incidence, the pressure difference of blade tip and the transverse pressure gradient of flow passage near the tip wall were enhanced, the total flow loss of the cascade was also increased at the same time.