利用双波纹凹槽改善气膜冷却效率的数值研究  

Numerical Study on Improving Film Cooling Effectiveness With Double-wave Trench

作　　者：张博伦 张丽[1] 朱惠人[1] 魏建生[1] 付仲议 ZHANG Bo-Lun;ZHANG Li;ZHU Hui-Ren;WEI Jian-Sheng;FU Zhong-Yi(School of Power and Energy,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学动力与能源学院

出　　处：《工程热物理学报》2019年第8期1894-1903,共10页Journal of Engineering Thermophysics

基　　金：国家重点基础研究发展计划资助项目(No.2013CB035702)

摘　　要：为提高带凹槽气膜孔下游壁面射流展向覆盖的均匀性,在横向凹槽的基础上提出了双波纹凹槽,通过数值模拟的方法对横槽和双波纹槽进行研究,同时分析了槽宽,槽深对双波纹凹槽气膜冷却特性的影响。结果表明,与横槽结构相比,双波纹凹槽下游壁面产生内卷对涡,射流更均匀贴覆在下游壁面,在高吹风比条件下展向平均冷却效率提高20%~63%。随着双波纹槽槽宽的变窄,导流作用增强,下游壁面孔中心线处冷却效率逐渐降低,孔中间线处冷却效率逐渐升高。在低吹风比0.5条件下,随着槽深的增加下游壁面的展向平均气膜冷却效率提高,在高吹风比2.0条件下,槽宽W=2.1D结构随着槽深增加展向平均气膜冷却效率几乎不变,但下游壁面射流展向均匀性明显提高。Double-wave trench was proposed on the basis of transverse trench to get wider laterally coverage of the cooling jet.Film cooling characteristics have been numerically studied for transverse trench and double-wave trench.Meanwhile,the film cooling effectiveness of double-wave trench at different trench width (W=0.8D,1.4J9,2.ID) and trench depth (H=0.75D,ID) conditions are investigated.The results show that double-wave trench effectively improves the film cooling effectiveness and the uniformity of jet at the downstream.The span-wise averaged film cooling effectiveness of the double-wave trench model increases 20%~63% comparing with that of the transverse trench at high blowing ratio condition.The anti-counter-rotating vortices which can press the film on near-wall are formed at the downstream double-wave trench.With the double-wave trench width decreasing,the film cooling effectiveness gradually decreases at the hole center-line region of the downstream trench,on the contrary,the cooling effectiveness increases at the hole middle region of the downstream trench,which is because of that nairowing trench width makes guidance action enhanced.With the increase of the trench depth,at low blowing ratio of 0.5 condition,the span-wise averaged film cooling effectiveness of downstream trench increases;at high blowing ratio of 2.0,the double-wave trench W=2.ID condition,the span-wise averaged film cooling effectiveness is almost unchanged,but span-wise uniformity of jet is significantly improved.

关 键 词：气膜冷却 展向均匀性 双波纹凹槽 导流作用 内卷对涡 

分 类 号：V231.1[航空宇航科学与技术—航空宇航推进理论与工程]