Numerical Study on the Influence of Hole Shape on Film Cooling Effectiveness

摘要

Effects of hole shapes on film cooling effectiveness downstream of one row of film holes at the blade were investigated using a three-dimensional finite volume method and multi-block technique. The present study also received velocity vectors about different hole shapes. The hole geometries studied include standard cylindrical hole and forward diffused shaped hole and converging slot-hole. It was found that the film cooling effectiveness of cylindrical holes obviously declined along with increasing the blowing ratio. Results of the shaped holes configuration present a marked improvement, with a high effectiveness at the lateral area between adjacent holes and effectiveness of the converging slot-hole was superior to other holes in various blowing ratios. The film cooling effectiveness realized by the slot-holes compared to the cylindrical and forward diffused shaped holes was more excelled at downstream of the intersection of the two slot-holes. The converging slot-hole and forward diffused shaped hole can reduce the vortex intensity, and then enhance the film cooling effectiveness.