论文部分内容阅读
以饱和多孔介质内流体流动、流体和固体传热为研究对象,考虑流体密度随温度变化,局部热平衡,引入Brinkman-Forchheimer的扩展Darcy模型进行修正,建立固体随机堆积饱和多孔介质自然对流数值模型,采用有限体积法计算.利用自主研制的两侧恒温差立方体多孔介质实验台,对数值模型进行实验验证.综合数值计算和实验结果表明:腔体内最大流速随温差和瑞利数Ra增大而增大,且最大流速出现在高低温壁面附近;随着Ra增大,温度等值线由近似于平行于高低温壁面变为近似垂直于高低温壁面;高温壁面上Nu从上至下呈线性增加趋势;高温壁面Nu随Ra增大而增大,当Ra<102时,Nu维持在12以内;当102106,Nu增加速率很小.
In this paper, the heat transfer of fluid and solid in saturated porous media is taken as the research object. The fluid density is changed with the temperature and the local thermal equilibrium. The Brinkman-Forchheimer extended Darcy model is introduced to modify the natural convection numerical model of porous solid saturated porous media. The finite volume method was used to calculate the numerical model.The experimental results show that the maximum flow velocity in the cavity increases with the temperature difference and Rayleigh number Ra Large and the maximum flow rate appears near the high and low temperature wall. As Ra increases, the temperature contour changes from approximately parallel to high and low temperature to near vertical to high and low temperature. On the high temperature wall, Nu increases linearly from top to bottom Nu of Nu remained at 12 when Ra <102; Nu increased rapidly from 11.4 to 276.4 at 102 106, Nu increased at a rate of Very small.