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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 this paper, the numerical simulation of the flow field and the temperature field around the infinitely long circular pipe covered with porous media is carried out. The effects of the dimensionless thickness ep, the Darcy number D_a and Reynolds number Re on the flow and forced convection heat transfer characteristics Impact. The results show that the forced convection heat transfer after the tube is coated with porous media is obviously stronger than that under the condition of the light tube, and the heat transfer increases by 2.8 ~ 5.4 times. The average Nusselt NU increases with e_p and Re But decreases with the increase of Da. The flow resistance coefficient C_D at the wall increases with the increase of ep, and then increases with the decrease of D_a first and then decreases. When Da is less than 1 × 10 ~ (-5), the drag coefficient remains unchanged.