温比对双向扩张孔射流气膜冷却效率的影响

摘要

To explore the difference of film cooling characteristics between small temperature ratio and real temperature ratio of the coolant and gas,the flow field,temperature field and film cooling efficiency of 3-in-1 hole inj ection film were studied,on the basis of Fluent software,by using the realizable k-εmodel with temperature ratio of 1.1 and 2.0,the blowing ratio of 0.5 and 2.0.The results show that,at blowing ratio of 0.5,the diffusions of coolant with both temperature ratios are identical and the radial average cool-ing efficiency has little difference.At blowing ratio of 2.0,the coolant radial diffusion with temperature ra-tio of 2.0 is better than that with temperature ratio of 1.1.The radial average cooling efficiency with tem-perature ratio of 2.0 is about 13.4% to 55.5% higher.%为了探讨冷热流体真实温比与小温比的气膜冷却特性差别,采用湍流模型及 Fluent 软件,对吹风比Br分别为0．5和2．0,温比Tr分别为1．1和2．0的双向扩张孔射流气膜的流场、温度场和冷却效率分布进行研究.结果表明：Br＝0．5时,2种温比下的冷气扩散基本一致,径向平均冷却效率差别不大；Br＝2．0时,Tr＝2．0的冷气径向扩散优于Tr＝1．1的,径向平均冷却效率较Tr＝1．1时增幅13．4％~55．5％.