涡轮叶片多排气膜叠加特性及机理分析

The film holes on the actual turbine vanes sometimes need to be guaranteed limited opening rate due to strength requirements. In order to study the film cooling effectiveness and superposition characteristics on the turbine vane for different film hole layouts at the same opening ratio，the paper investigated the distribution of film cooling effectiveness and film superposition and mixing mechanism of single-row，three-row and five-row cylindrical holes and fan-shaped holes layouts at different blowing ratios. It was found that hole shape is an important geometric factor affecting the film superposition prediction accuracy，and the superposition prediction accuracy of fan-shaped hole is significantly higher than that of cylindrical hole. The strength of the kidney vortex is the main reason for the difference. The blowing ratio and the number of rows of holes also significantly affect the accuracy of superposition prediction model. Increasing blowing ratio causes the prediction error to increase gradually. The blowing ratio determines the momentum of the cooling jet，which affects the film mixing strength thus contributing to the phenomenon that increasing the number of rows of holes causes a gradual increase in the prediction error. It can significantly increase the film superposition prediction error when the cooling jets blow off.