多孔介质壁面封闭腔体自然对流传热的数值模拟

Numerical simulation on natural convection heat transfer in enclosure with a porous media wall

多孔介质壁面封闭腔体的自然对流在太阳能暖房、蓄热腔体等中有重要的应用。该文针对左侧部分多孔介质壁面矩形封闭腔体,基于有限元法对封闭腔体的自然对流换热进行了数值模拟,得到了在不同Ra数、宽高比A以及不同壁面工况条件下腔体内空气的速度分布,同时获得右壁面的平均Nu数。研究结果表明:随着A的增大,腔体内的流动减弱,右壁面换热减弱;而左侧部分多孔介质壁面对腔体的流动换热产生很大的影响。

Natural convection in closed cavity with porous media wall has been importantly applicated in the solar energy greenhouse, heat storage chamber etc. In this paper, part of the left wall of rectangular enclosed cavity is porous medium, natural convection in this enclosed cavity has been simulated by using the finite element method. The velocity distribution of air in cavity and the average Nu number of right wall has been obtained with different Ra number, aspect ratio A and different wall conditions.The results show that： with the increasing A the flow in the cavity becomes weaken, the heat transfer of fight wall also becomes weaken as well; the left wall with part of porous media has a huge impact on the flow and heat transfer in cavity.