管外包覆多孔介质强化换热的数值研究  

Numerical Simulation of Heat Transfer Enhancement of a Solid Cylinder Wrapped with a Porous Layer

作　　者：王会[1] 郭烈锦[1] 叶晶[1] 陈康[1] 刘威志[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《工程热物理学报》2015年第2期423-426,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金创新群体项目(No.51121092);国家自然科学基金重点项目(No.51236007)

摘　　要：本文对管外包覆多孔介质的无限长圆管绕流的流场和温度场进行数值模拟,研究了多孔介质层的无量纲厚度ep,达西数D_a以及雷诺数Re对流动和强制对流换热特性的影响。研究结果表明,管外包覆多孔介质后的强制对流换热效果明显强于光管条件下的效果,换热增强了2.8~5.4倍;壁面平均努塞尔数Nu随e_p和Re的增大而增大,随Da的增大而减小;管壁处的流动阻力系数C_D随ep的增大而增大,随D_a的减小,先增大后减小,当Da小于1×10^(-5)时,阻力系数保持不变。In the present study flow-field and temperature-field around a cylinder wrapped with a porous layer are investigated numerically.Effects of several parameters,such as porous layer thickness e_p and permeability Da as well as Reynolds number on flow-field and heat transfer characteristics are examined.The numerical results indicate that the presence of a porous layer has a strong effect on the heat transfer enhancement around the cylinder.The heat transfer is about 2.8~5.4 times enhanced compared to that around a cylinder without a porous layer.The wall averaged Nusselt number increased when e_p or Re increased,and decreased with Da increased.The drag coefficient C_d increased with the increase of e_p,but it increased as the speed increased initially and decreased afterwards,then it remains unchanged when Da <1×10^(-5).

关 键 词：多孔介质 强化换热 强制对流换热 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]