模拟叶尖间隙流的转动平面叶栅实验方案

通过对动叶叶尖进口端壁附面层的性状分析指出：采用平面叶栅模拟动叶叶尖间隙流时，端壁面静止和仅有端壁面运动进口端壁附面层与真实情况存在较大差异。根据转子静止、静子转动这一相对运动思想研制出动叶叶尖间隙流实验台。通过对叶尖附近叶片表面静压分布和间隙泄漏流量实验测量表明：端壁面与叶片之间的相对运动、进口端壁附面层内速度分布是对叶尖间隙流有重要影响的因素。

Development of Rotating Linear Cascade Facility for Simulating Blade Tip Clearance Flow

From the analysis of the shape of end wall boundary layer at the entrance of rotor blade tip, the discrepancy in the boundary layer between a cascade without end wall motion or a linear cascade only with end wall motion and real circumstances is pointed out. From the relative motion concept of fixed rotor and rotating stator, the experimental device for simulating rotor blade tip clearance flow is designed. The device has two rows of blades. The front row simulates that of inlet static vanes fixed on a rotating belt; the downstrearn row simulates that of rotor blades, which are static. According to the experimental results of pressure distribution on the blade surface and blade tip leakage flow, it is shown that the relative motions between the end wall and the blade and the velocity distribution in the boundary layer at the clearance entrance have important influence on the blade tip clearance flow. Therefore, for practical use of experimental results in linear cascades, the above two factors should be carefully considered.