关键词: 反弯曲叶片, 流场, 试验研究, 涡轮静叶栅, 加卸载, 接触刚度, 接触阻尼, 结合面, 微凸体

Abstract: Experimental investigations on the flow fields of a classical blade profile cascades are carried out with different bowed blades. The exit flow fields of straight cascade and the negative bowed cascades with bowed angles –10°，–20° are measured. The results show that for the present blade profile, with the increasing of the bowed angle, the intensity and scale of the exit passage vortex increase slightly, while the position of the exit passage vortex does not change obviously, the intensity of the exit tail vortex decreases, both the secondary flow at midspan and endwall increase; the total pressure loss at midspan does not change obviously, however the total pressure loss at endwall increases acutely and the total pressure loss of the whole cascade increase as the result, the total pressure loss of straight blade cascade are the lowest.

Key words: Experimental investigation, Flow field, Negative bowed blade, Turbine stator cascade, Asperity, Contact damping, Contact stiffness, Loading and unloading, Mechanical joint