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提出了一种高孔隙率开孔泡沫金属的结构简化几何模型,运用热电比拟理论在胞孔尺度上分析并求解了有效热导率的计算表达式,并根据已有实验数据进行模型修正.同时模拟分析了金属泡沫三维矩形通道内空气流动的对流换热情况,与实验结果进行了对比验证.研究表明,本文提出的胞孔有效热导率修正模型对铝泡沫金属有一定的适用性;相同孔隙率条件下,泡沫金属通道内强制对流的对流换热系数随孔密度的增加(即孔径的减小)而增大,但付出的代价是阻力也随之增大;相对而言,低孔密度的泡沫金属具有较好的对流换热综合性能.
A simplified geometrical model of highly porous metal foam with open porosity was proposed. The thermodynamic simulation theory was used to analyze and calculate the effective thermal conductivity at the cell scale, and the model was modified according to the existing experimental data. The convective heat transfer of air flow in three-dimensional rectangular channel of metal foam was simulated and verified with the experimental results.The results show that the proposed model of effective thermal conductivity correction of the cell has some applicability to aluminum foam metal, Under the condition of porosity, the convective heat transfer coefficient of forced convection in the foam metal channel increases with the increase of the pore density (ie, the decrease of the pore diameter), but at the expense of increased resistance; in contrast, The density of metal foam has better convective heat transfer performance.