圆角横槽结构对气膜冷却效率影响的实验研究

为了研究圆角横槽结构对气膜冷却效率的影响,选取槽深、槽宽、圆角半径、吹风比四个影响因素进行正交实验,采用压力敏感漆测试技术对圆孔冷却结构和圆角横槽结构的气膜冷却效率进行测试。结果表明：在低吹风(BR=0.5)、中吹风(BR=1)比、高吹风(BR=1.5)比下,除Case3外,圆角横槽的面平均气膜冷却效率均高于单一圆孔。圆角横槽的面平均气膜冷却效率相对于圆孔冷却结构最高可以提高127％,Case1-Case9中,优化组合的结构参数为：槽宽2.4D,槽深0.6D,圆角半径0.9D,优化组合面平均气膜冷却效率相对于气膜冷却效率最低的Case8可以提高177％。在槽宽、圆角半径、槽深、吹风比四个影响因素中,吹风比对圆角槽气膜冷却效率影响程度最大,其次分别是槽深、槽宽、圆角半径。

Experimental Study on Effects of Structure of Fillet Cross Groove on Film Cooling Efficiency

In order to study the influence of fillet cross groove structure on the film cooling efficiency, the orthogonal experiments were carried out by four factors: groove depth, groove width, fillet radius and blowing ratio. The film cooling efficiency of circular hole cooling structure and fillet cross groove structure was tested by pressure sensitive paint test technology. The results show that under the conditions of low blowing (BR = 0.5), medium blowing (BR = 1) and high blowing (BR = 1.5), except Case 3, the surface average film cooling efficiency of the fillet cross groove is higher than that of the single round hole. The surface average film cooling efficiency of the fillet transverse groove can be increased up to 127% compared with the round hole cooling structure, in Case 1-Case 9, the optimized combination of structural parameters is: groove width 2.4D, groove depth 0.6D, fillet radius 0.9D, and the optimized combination of surface average film cooling efficiency can be increased by 177% compared with Case 8, which has the lowest film cooling efficiency. Among the four factors of groove width, fillet radius, groove depth and blowing ratio, blowing ratio has the greatest influence on the film cooling efficiency of fillet groove, followed by groove depth, groove width and fillet radius.