两排圆孔的气膜冷却特性  

Flow Characteristics and Superposition Rule of Two Rows of Round Holes

作　　者：王浪[1] 李雪英[1] 任静[1] 蒋洪德[1] 

机构地区：[1]清华大学热能工程系,北京100084

出　　处：《工程热物理学报》2017年第5期1082-1086,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51376099)

摘　　要：气膜冷却被广泛地应用在现代透平冷却设计中。对于很多热端部件,为了保证足够的冷却效果,其表面需要布置多排气膜孔来得到更高的冷却效率,Sellers叠加公式是目前多排孔设计当中最常用的叠加方法。本文采用PSP技术研究了单排圆孔与两排圆孔的在不同吹风比和密度比下气膜冷却特性,并同时进行了相应工况下的数值计算来获得更详细的流场信息,Sellers叠加公式预测结果也进行了比较以探索其适用范围。结果表明,对于圆孔的气膜冷却,在低吹风比时,第二排孔基本不受第一排孔影响;在高吹风比时,由于前排孔出气对主流的推举作用,后排孔更容易吹离,冷却效果变差。而Sellers叠加公式仅在低吹风比高密度比时预测结果较好,其余工况预测偏大。Film cooling technique is widely used in a modern gas turbine. Many applications in hot sections require multiple film cooling rows to get better cooled. In most design situations the additive effect of multiple rows is computed by single row of holes, the most widely used method is the Sellers superposition method. In this paper, one row of round holes and two rows of round holes are investigated by PSP technology. The effect of blowing ratio （M=0.25, 0.5, 0.75, 1.0） and density ratio （DR=1.0, 1.5） are studied. Numerical simulations are also conducted to gain more flow field information. It is found that the cooling effectiveness after the second row of holes is nearly not effected by the first row of holes at low blowing ratio, while for high blowing ratio cases, the cooling effectiveness become lower because of the detachment. The results by Sellers method are similar to experiment results only at low blowing ratios and high density ratios, and the results of Sellers are always higher than experimental results.

关 键 词：燃气轮机 多排孔 气膜冷却 叠加公式 

分 类 号：TK474.7[动力工程及工程热物理—动力机械及工程]