The effective thermal conductivity of porous materials is determined by many factors. Previous works were mainly focused on the pore content and the thermal conductivity of two components. However, few researches pay attention to the effects of pore complex shape, overlap and distribution. In this study, the effects of pore complex shape, distribution and overlap are investigated at the same time. It is found that the best pore should have relatively larger contact areas in the direction vertical to heat flux. I-shaped and T-shaped pores have the larger contact area in any type of the pore distributions. They have the most impact on the thermal conductivity of the porous material. I-shape pore with directional distribution is better than random distribution. The rhombic, elliptical and rectangular pores have larger thermal insulation in random distribution than in directional distribution. The efficiency of square, triangular and T-shaped pores are similar in directional and random distributions. The pore overlap only has the apparent effect on the I-shaped pore. New methods to control the distribution and overlapped direction of pores should be investigated in the future.

中文翻译：

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孔复合形状、分布和重叠对多孔保温材料导热系数的影响

多孔材料的有效导热系数由多种因素决定。以前的工作主要集中在两个组件的孔隙含量和热导率上。然而，很少有研究关注孔隙复杂形状、重叠和分布的影响。本研究同时考察了孔隙复杂形状、分布和重叠的影响。发现最好的孔隙在垂直于热通量的方向上应该有相对较大的接触面积。I形和T形孔在任何类型的孔分布中都有较大的接触面积。它们对多孔材料的热导率影响最大。定向分布的工字孔优于随机分布。菱形，椭圆形和矩形孔在随机分布时比在定向分布时具有更大的隔热性。方形、三角形和 T 形孔的效率在方向和随机分布方面相似。孔隙重叠仅对工字形孔隙有明显影响。未来应该研究控制孔隙分布和重叠方向的新方法。