非均匀多孔介质有效热导率分析

本文采用控制容积法,界面调和平均导热系数值以及图形处理方法对典型非均匀多孔介质硬质聚氨酯泡沫材料的导热过程进行了分析与模拟计算。结果表明:多孔介质的内部结构是影响温度分布和热量传递的主要的因素,其影响程度与骨架和孔隙的导热系数,孔隙的大小和分布有关;计算得到的有效热导率值与文献中实验测量结果吻合较好。本文的研究结果可以推广到更为复杂的非均匀多孔介质的场合,从而可以进一步认识非均匀多孔介质中的导热规律,为工程计算提供更精确的计算方法。

ANALYSIS OF EFFECTIVE THERMAL CONDUCTIVITY FOR NON-UNIFORM POROUS MEDIA

In this paper, heat conduction in rigid polyurethane foam, one kind of typical non-uniform porous media, is analyzed and simulated, in which finite volume method and interface harmonic average thermal conductivity are adopted. The calculated results show that inner structure acts as the main influencing factor. The influencing degree is consequent on the thermal conductivities of both matrix and pore. The calculated effective thermal conductivity agrees well with the experimental data. The conclusions of this work can be extended to more complicated situations of non-uniform porous media and can be used for engineering calculation.