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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和局部热平衡,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,对所建数值模型进行实验验证。综合数值计算和实验结果表明:多孔介质方腔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温壁面和低温壁面附近;随着Ra增大,温度等值线由近似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。
Taking the fluid flow and fluid and solid heat transfer in saturated porous media as the research objects, the extended Darcy model of Brinkman-Forchheimer was introduced to consider the fluid density change with temperature and the local thermal equilibrium, and a numerical model of natural convection in solid random packing and saturated porous media was established. Calculated using the finite volume method. The experimentally verified numerical model was established by using self-developed two-sided constant temperature difference cubic porous media bench. The results show that the maximum flow velocity increases with the increase of temperature difference and Rayleigh number Ra, and the maximum flow velocity appears near the high temperature wall and the low temperature wall. As Ra increases, the temperature contour Which is approximately perpendicular to the high and low temperature walls. The Nu of the high temperature wall shows a linear increase trend from top to bottom. The Nu of the high temperature wall increases with Ra increasing. When Ra <102, Nu maintains at 12 ; When 102 106, Nu increased very little.