堵塞比对波纹板隔热屏冷却性能的影响  

Effects of Blockage Ratio on Cooling Characteristics of Wave Heat Shield

作　　者：刘友宏[1] 陈超 任浩亮 

机构地区：[1]北京航空航天大学能源与动力工程学院航空发动机气动热力国家重点实验室,北京100191

出　　处：《科学技术与工程》2018年第4期169-174,共6页Science Technology and Engineering

摘　　要：以一种气膜冷却的波纹板隔热屏为研究对象,在保持波纹板隔热屏的波纹长度、波纹高度、以及开孔方式不变的情况下,通过在次流通道添加不同大小的堵塞物得到一系列不同堵塞比的几何模型,并由Navier-Stokes方程组建立了流场三维数值计算模型,进行了流/热/固耦合数值模拟研究,获得了不同堵塞比对隔热屏壁面Nu、气膜冷却效果、冷流体热负荷、以及气膜孔流量系数的影响规律。结果表明:隔热屏热侧壁面Nu受堵塞比影响不大,冷侧壁面Nu在距离堵塞物较远处受堵塞比影响不大,在距离堵塞物较近处随堵塞比的增大而减小;气膜冷却效果在隔热屏主流背风侧靠近波谷处较高,在主流迎风侧靠近波峰处较低,隔热屏的综合平均冷却效果受堵塞比的影响不大;隔热屏单位面积冷流体热负荷随堵塞比增大而线性增大;气膜孔流量系数受堵塞比的影响不大,其最大值相比最小值变化了4.05%。Based on a film cooling wave heat shield,geometric models with different blockage ratio were obtained by changing the size of the blockage which were added in the cool side,but with the constant wave length,wave height and film cooling hole shape. Then the three-dimensional numerical simulation model based on the Navier-Stokes equation was created. Through numerical simulation,the principle of the effects of different blockage ratio on the wall Nusselt number,cooling effectiveness of film hot surface,cool fluid heat load,and discharge coefficient of the cooling holes were obtained. The results show that lockage ratio has little effect on the hot side wall Nusselt number of the shield,while the cold side wall Nusselt number of the shield which is near the blockage declines as the blockage ratio increases. The cooling effectiveness of film hot surface which is near the hot troughs is higher,the cooling effectiveness of film hot surface which is near the hot crests is relatively low,and that the overall cooling effectiveness of film hot surface changes little with the blockage ratio changes. The cool fluid heat load increases with the change of blockage ratio linearly. The discharge coefficient of all holes changes little with the minimum value lower 4. 05% than the maximum.

关 键 词：堵塞比 波纹板隔热屏 气膜冷却 冷却效果 冷流体热负荷 流量系数 

分 类 号：TV19[水利工程]