内通道交错横流对气膜冷却效率的影响

白江涛; 朱惠人; 刘存良

内通道交错横流对气膜冷却效率的影响

西北工业大学动力与能源学院, 西安 710072

基金项目: 国家973计划(2007CB707701)

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出版历程
- 收稿日期: 2007-07-14
- 修回日期: 2007-10-23
- 刊出日期: 2008-08-28

Numerical study of the effect of internal coolant crossflow on film cooling effectiveness

School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China

摘要

摘要: 采用数值模拟研究了内通道横流对气膜流动和冷却特性的影响,参数变化范围:横流比Cr=0.39,0.78;吹风比Br=1,2;气膜孔长径比l/d=4,8.计算结果表明:①内通道冷气横流使得气膜孔内气流产生较强的涡旋,使得冷气射流的流动具有明显的非对称特征,引起表面气膜冷却效率分布不均;②横流比对表面气膜冷却效率分布影响较大,横流比越大,气膜孔内涡旋越强烈,气膜冷却效率分布越不均匀;③长径比较大时,气膜孔内气流较为规整,气膜覆盖区域较为狭小,气膜冷却效率分布更加不均;吹风比较大时,射流在主流通道上的附着较差,气膜冷却效率较低.
- 交错流动 /
- 气膜冷却 /
- 冷却效率
Abstract: This paper investigated numerically the effect of a coolant crossflow on film cooling effectiveness.Computations were performed to investigate the three-dimensional film cooling flow and cooling effectiveness with two crossflow ratios(Cr=0.39,0.78) and two blowing ratios(Br=1,2) and two length to diameter ratios(l/d=4,8).The results of the present investigation show that there is a profound effect of how the coolant is supplied to the hole on the film-cooling performance in the near hole region,for example,crossflow ratio has great influence on the film-cooling effectiveness of surface,a bigger length to diameter ratio brings about regular flow within film holes,and a bigger blowing ratio leads to poorer adhesion of jet stream and lower film-cooling effectiveness.Therefore,crossflow at the hole entry side has to be taken into account when modeling film-cooling schemes of turbine blades.
- crossflow /
- film cooling /
- effectiveness

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参考文献(7)

[1]	葛绍岩,徐靖中.气膜冷却[M].北京:科学出版社,1985.
[2]	Eriksen V L.Film cooling effectiveness and heat transfer with injection through holes[R].NASA Report CR-72991.
[3]	Bogard D G,Thole K A.Gas turbine film cooling[J].Journal of Propulsion and Power,2006,22(2):249-270.
[4]	Gritsch M,Sehulz A,Wittig S.Film-cooling holes with expanded exits:near-hole heat transfer coefficients[J].International Journal of Heat and Fluid Flow,2000,21(2):146-155.
[5]	Gritsch M,Schulz A,Wittig S.Effect of internal coolant crossflow on the effectiveness of shaped film-cooling holes[J].Journal of Turbomachinery,Transactions of the ASME,2003,125(3):547-554.
[6]	Lin Y L,Shih T I P.Film cooling over flat,convex,and concave surfaces[R].AIAA A99-16245.
[7]	Goldstein R J,Eckert E R G,Ramsey J W.Film cooling with injection through holes:adiabatic wall temperatures downstream of a circular hole[J].Journal of Engineering for Power,Transactions of ASME,1968,90(4):384-395.