狭缝射流冲击柱状凸形表面流动换热特性  

Flow and heat transfer characteristics of slot jet impingement to a cylindrical convex surface

作　　者：柳翠翠[1] 姜泽毅[1] 张欣欣[1] 马强[2] 孙雨生[2] 

机构地区：[1]北京科技大学机械工程学院,北京100083 [2]中国航空规划建设发展有限公司。北京102206

出　　处：《北京科技大学学报》2012年第4期444-449,共6页Journal of University of Science and Technology Beijing

摘　　要：采用数值方法研究了狭缝射流冲击柱状凸形表面的流动换热特性,通过四种湍流模型计算结果与实验数据对比,确定了湍流模型适用性.以压力梯度分布为依据,重点分析了狭缝射流沿柱状凸形表面的流动结构和边界层分离特点及柱状凸形表面的强化换热特性.结果表明:RNG k--ε和Realizable k--ε模型具有预测适应性;狭缝射流冲击至柱状凸形表面,气体沿表面运动,速度降低,并在流动下游发生边界层分离;量纲一的逆压梯度随量纲一的曲率半径(D/B)的减小而增大,使得边界层分离更早出现;驻点区域换热Nu随量纲一的曲率半径(D/B)的减小而获得增强,但流动进入下游后,D/B对换热基本无影响;压力梯度是影响狭缝射流冲击柱状凸形表面换热分布的重要因素.The flow and heat transfer characteristics of slot jet impingement to a cylindrical convex surface were investigated by the numerical method.Suitable turbulence models were determined by comparing experimental data with the numerical results of four turbulence models.The flow structure,boundary layer separation and wall heat transfer enhancement characteristics of slot jet impingement to a cylindrical convex surface were discussed on the basis of the pressure gradient distribution.The results show that RNG k-ε and Realizable k-ε models are suitable to predict.The slot jet impinges to a cylindrical convex surface,the gas flows along the convex surface,the velocity decreases and the boundary layer separation appears downstream.The dimensionless adverse pressure gradient increases with the dimensionless radius of curvature（D/B） decreasing,leading to an earlier boundary layer separation.Nu in the stagnation region can be enhanced by decreasing D/B.However D/B has almost no effect on heat transfer in the downstream flow.The pressure gradient is a key factor in affecting the heat transfer distribution in slot jet impingement to a cylindrical convex surface.

关 键 词：狭缝射流 凸形表面 湍流模型 边界层 换热 

分 类 号：TK124[动力工程及工程热物理—工程热物理]