内冷通道横流条件下气膜冷却特性

Film cooling performance with internal coolant channel crossflow

为了研究内冷通道横流条件下气膜冷却的流动和换热特性,采用窄带瞬态液晶测量技术获得了内冷通道横流条件下吹风比分别为0.5,1,2时气膜孔下游冷却效率和表面传热系数云图,并通过数值模拟得到了气膜孔内及下游区域流场的详细信息.结果表明:内冷通道横流对气膜孔下游冷却效率和表面传热系数分布有重要的影响.横流增强了气膜孔射流的展向分布能力,增强了高吹风比时气膜冷却效果.另外,气膜孔下游涡的分布出现明显的不对称性,涡的结构更加复杂.

In order to investigate the flow and heat transfer performance of film cooling with internal coolant channel crossflow,narrowband transient liquid crystal measurement technique was used to gain the contours of cooling effectiveness and heat transfer coefficient downstream the film cooling hole for blowing ratios of 0.5,1and 2 with internal coolant channel crossflow,and the detailed flow field characteristics inside film cooling hole and downstream region were obtained by numerical simulation.The results show that the internal coolant channel crossflow has a notable effect on distributions of cooling effectiveness and heat transfer coefficient downstream the film cooling hole.The crossflow enhances the ability of lateral spreading of film cooling hole injection,and the film cooling effect is improved at high blowing ratio.Furthermore,the asymmetric vortices appear downstream the film cooling hole,and the structures of vortices are more complicated.