低长径比下双波纹孔气膜冷却效率分析  

Analysis of Cooling Efficiency of Double-corrugated Holes at Low Length-to-Diameter Ratio

作　　者：杨晓军 常嘉文 刘智刚 刘文博 柳笑寒 于浩洋 Yang Xiaojun;Chang Jiawen;Liu Zhigang;Liu Wenbo;Liu Xiaohan;Yu Haoyang(Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学,天津300300

出　　处：《航空科学技术》2021年第5期31-38,共8页Aeronautical Science & Technology

基　　金：中国民航大学中央高校基本科研业务费项目(3122019187)。

摘　　要：为了提高低长径比(L/D=2)下气膜孔的冷却能力,本文提出一种双波纹孔的新型气膜孔结构。选取圆柱孔、扇形孔和猫耳孔作为对比孔型,应用数值模拟的方法对4种孔形的流场和冷却效率进行了研究。结果表明,双波纹孔的出口面积较大,其支孔结构能够减弱气膜孔进口射流的影响,降低气膜孔中的"空腔"区域,使冷却空气流动更加合理。低吹风比(M=0.5)时,双波纹孔气膜中心的高冷却效率区域更大,高吹风比(M=1.5)时,双波纹孔后气膜会出现"缩颈"现象,其中心线上的冷却效率约为0.3以上,展向平均冷却效率约在0.1以上,优于其余三孔。当吹风比提高到M=2.5时,扇形孔的冷却效率略优于双波纹孔,但展向平均效率基本一致,综上双波纹孔在低长径比下具有良好的冷却效率分布,为航空发动机薄壁热端部件挖掘冷气的冷却潜力提供一个可行方案,希望为相关研究和设计提供借鉴和参考。In order to improve the cooling capacity of film cooling at low length-to-diameter ratio(L/D=2).This paper proposes a new structure of double-corrugated hole.Cylindrical hole,Fan-shaped hole and NEKOMIMI hole are selected as the comparison holes.The flow field and cooling efficiency of the four holes are investigated by applying numerical simulation methods.The results show that the exit area of double-corrugated hole is larger and its branch structure can reduce the influence of jetting from inlet,which can reduce the"cavity"area inside the hole so that the cooling flow will be more effective.When the blowing ratio is low(M=0.5),the film center of double-corrugated holes covers more area which has higher cooling efficiency,and when the blowing ratio is high(M=1.5),the film behind double-corrugated hole appears"necking"phenomenon,the cooling efficiency on the center line is about 0.3 or above,and the average cooling efficiency in the spreading direction is about 0.1 or more,which is better than the remaining three holes.When the blowing ratio is increased to M=2.5,the cooling efficiency of fan-shaped hole is slightly better than that of the double-corrugated hole,but the average efficiency in the spreading direction is almost the same.In summary,the double-corrugated hole has a good cooling efficiency distribution at low length-to-diameter ratio.Which provides a feasible solution for exploiting the cooling potential of thin-walled hot end components of aeroengine.This paper is expected hopes to provide reference for relevant research and design.

关 键 词：气膜冷却 双波纹孔 长径比 冷却效率 分支孔 

分 类 号：TK471[动力工程及工程热物理—动力机械及工程]