摘要
在不同吹风比下,对新型缩放槽缝孔和新型月牙孔气膜冷却结构的流动过程和气膜冷却效率进行了数值研究,并与常规圆柱孔进行了对比,以揭示新型孔改善气膜冷却效果的机理。在所研究吹风比的范围内,两种新型孔的冷却效果都好于圆柱孔,且其冷却效率曲线上移的幅度与吹风比成正比关系。高吹风比时,缩放槽缝孔在气膜孔下游中心线x方向上的冷却效率曲线和两个气膜孔之间z方向上的横向冷却效率曲线上移显著。通过优化气膜孔的结构,新月牙形孔可以有效降低反向涡对的强度,从而削弱了气膜对主流的穿透力,气膜冷却较好。新型缩放槽缝孔在绝热壁面上形成了一对与反向涡对不同的耦合涡,这对耦合涡使气膜的贴壁效果更好,提高了气膜孔的冷却效率。
The flow fields and cooling effectiveness of the film cooling from new converging slot-hole and new crescent hole configurations were studied numerically in different blowing ratios.Their distributions were compared with the distributions of cylindrical hole to reveal the effects of new film hole on the film cooling performance.It was found that,in any blowing ratio,the cooling efficiency of 2 new holes are higher than that of the cylindrical hole,and cooling effectiveness increase is greater along with the blowing ratio increasing.Converging slot-hole on the downstream of the film hole centerline effectiveness and the lateral effectiveness obviously improve at high blowing ratio.Through the optimization of film hole configuration,the strength of the counter rotating vortex pairs are greatly suppressed by crescent hole,and jet flow vertical penetration to mainstream ability is weakened,lead to the film better coverage.New converging slot-hole formed a pair of coupling vortexes that different with counter rotating vortex pairs in adiabatic wall,the coupling vortexes make the air film adherent good effect,so the cooling effectiveness of the film holes is improved.
作者
戴萍
林一帆
张雨
DAI Ping;LIN Yi-fan;ZHANG Yu(College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266061,China)
出处
《汽轮机技术》
北大核心
2021年第3期185-189,共5页
Turbine Technology
基金
山东省重点研发科技攻关资助项目(2019GGX104034)。
关键词
气膜冷却
新型孔
吹风比
数值计算
aerospace propulsion system
film cooling
new film hole
blowing ratio
numerical calculation
