叶片前缘波纹形气膜孔不同参数冷却特性研究

为了解决涡轮叶片前缘的冷却问题，提出结构简单的波纹形气膜孔的概念。对影响孔冷却特性的4个重要参数(吹风比、倾斜角、扩展角和后倾角),采用4因素4水平下的田口方法进行优化，并采用数值计算的方法将其冷却效率与参考孔型(圆柱形气膜孔)进行对比。其中，固定前缘孔间距30 mm,斜向倾角23°,并与试验保持一致。结果表明：吹风比为1、倾斜角为30°、扩展角为20°和后倾角为0°的波纹形气膜孔结构，壁面平均冷却效率达到0.36,冷却效果最佳；同时，随着吹风比的增大，该气膜孔结构前缘壁面平均冷却效率增长趋势明显，且在吹风比为2时冷却气流依旧具有良好的贴壁性能，壁面平均冷却效率超过圆柱形气膜孔82.96%。

Study on Cooling Characteristics of Different Parameters of Corrugated Holes at the Leading Edge of Blade

In order to solve the cooling problem of the leading edge of the turbine blade, the concept of corrugated holes with simple structure was proposed. The four important parameters affecting the cooling characteristics of the hole, such as blow ratio, inclination angle, expansion angle and backward inclination angle, were optimized by the Taguchi method under the four factor four level method, and the cooling efficiency was compared with the reference hole type (cylindrical hole) by numerical calculation, in which the fixed leading edge hole spacing of 30 mm and the oblique inclination angle of 23° were consistent with the test. The results show that the corrugated hole structure with a blowing ratio of 1, an inclination angle of 30°, an expansion angle of 20° and a backward inclination angle of 0° has an average cooling efficiency of 0.36 on the wall surface, and the cooling effect is the best; meanwhile, with the increase of the blowing ratio, the average cooling efficiency of the leading edge wall surface of the corrugated hole structure increases significantly, and when the blowing ratio is 2, the cooling air flow still has good adherent performance, and the average cooling efficiency of the wall surface exceeds that of the cylindrical hole by 82.96%.