孔径比与冲击距对冲击/发散冷却隔热屏冷却性能影响

Effects of Diameter Ratio of Holes and Impingement Distance on Cooling Performance of Impingement/Effusion Cooled Heat Shield

关键词:  冲击/发散冷却  气膜冷却  隔热屏  加力燃烧室  数值仿真

Key words:  Impingement/effusion cooling  Film cooling  Heat shield  Afterburner  Numerical simulation

摘要:

为了获得孔径比与冲击距对冲击/发散冷却层板隔热屏冷却性能的影响，采用商用软件Fluent，基于加力燃烧室隔热屏的工况条件，对7组不同孔径比和7组不同相对冲击距的冲击/发散层板模型进行了三维流固耦合传热数值模拟研究，得到了层板隔热屏内部被冲击表面的 Nu 数、层板隔热屏气膜冷却表面的冷却效果、层板隔热屏的冷气消耗和冷流体热负荷的变化规律，其对层板隔热屏的设计具有参考价值。结果表明， Nu 数与冷却效果均随着孔径比的增大而增大，随着冲击距的增大而减小。其中随孔径比增大，平均冷却效果值最大增大40.5%，随冲击距增大，平均冷却效果值最大减小3.27%。

Abstract:

In order to obtain the effects of diameter ratio of holes and impingement distance on cooling performance of impingement/effusion cooled heat shield，a series of 3D numerical simulation using Fluent with fluid/solid conjugated compute method of heat transfer were conducted under a working condition of heat shield in afterburner by studying seven models with different diameter ratios of holes and seven models with different impingement distances. Change laws of Nusselt number of impinged surface，cooling effect of film cooled surface，coolant consumption and coolant heat load have been obtained，which have a reference value to the design of lamilloy heat shield. Results show that both Nusselt number and cooling effect increase with the increase of diameter ratio of holes and decrease with the increase of impingement distance. The average value of cooling effect increases by 40.5% in maximum with the increase of diameter ratio of holes and decreases by 3.27% in maximum with the increase of impingement distance.