Influences of Blade Bowing on Flowfields of Turbine Stator Cascades

To understand the influences of blade positive and negative bowing on flowfields of turbine stator cascades with low aspect ratio, six sets of cascades with different bowed angles of the blades were designed and tested. A five-hole pitot microprobe, which was located upstream and downstream of the cascades, was used to survey the flowfields in detail. The results were different from other published results with a different kind of turbine stator blade profile. When a blade has positive or negative bowing, the passage vortices do not change, whereas the characteristics of the trailing vortices, such as the intensity, locations, size, and structure, do change distinctly. In the case of blade positive bowing, the local spanwise distribution of the yaw flow angle at the cascade exit is significantly affected, with very little changes in the cascade overall loss.