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.
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 filmcooling schemes of turbine blades.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2008年第8期1353-1358,共6页
Journal of Aerospace Power
基金
国家973计划(2007CB707701)
