扩压叶栅端壁角区流动结构和紊流特性

EXPERIMENTAL STUDY OF FLOW IN THE CORNER REGION OF A COMPRESSOR CASCADE

三维激光多普勒测速技术测量了扩压叶栅叶片和端壁相交的角区中的流动结构和紊流特性。实验结果表明，角区中端壁附面层和叶面附面层的堆积使得叶面附面层变厚；角区内存在较强的通道涡，随流动向下游发展，通道涡核心远离叶面；在前缘产生的马蹄涡逐步消失；通道涡使得角区的紊流动能增加，并影响雷诺正应力的分布。

The structure and turbulence characteristics of flow in the corner region (junction of the endwall and the suction surface of blade) of a compressor cascade passage were measured by using a three-dimensional Laser Doppler Velocimetry system. The result indicated that the interaction between the boundary layer on the suction surface of blade and on the endwall thicken the boundary layer on the suction surface. A strong passage vortex and a horse-shoe yortex was identified on the section at 7% chord of blade. With the movement to downstream,the passage vortex move to leave the suction surface of blade. The presence of the passage vortex has large effects on the behavior of the turbulence kinetic and Reynolds stress. The turbulence kinetic has a maxima in the core regions of the passage vortex.