CAJ | 학술논문

多孔泡沫是一类低密度、高比表面积、具有独特性能的新型功能材料。实际多孔泡沫材料通常是非均质的，即其孔隙结构分布是随机的。为研究非均质多孔泡沫材料的导热性能，提出用孔隙均匀度作为表征孔隙结构分布随机性的参数，以多孔石墨泡沫为例，分析孔隙均匀度对多孔泡沫有效热导率的影响。数值计算结果表明：孔隙结构分布越不均匀，多孔泡沫材料的导热性能越差。根据计算结果提出了非均质石墨泡沫相对有效热导率的预测式，并与现有文献报道的结果进行了比较，发现当前结果呈现了孔隙结构随机性对材料有效热导率的影响，与ORNL实验结果更吻合。
다공포말시일류저밀도、고비표면적、구유독특성능적신형공능재료。실제다공포말재료통상시비균질적，즉기공극결구분포시수궤적。위연구비균질다공포말재료적도열성능，제출용공극균균도작위표정공극결구분포수궤성적삼수，이다공석묵포말위례，분석공극균균도대다공포말유효열도솔적영향。수치계산결과표명：공극결구분포월불균균，다공포말재료적도열성능월차。근거계산결과제출료비균질석묵포말상대유효열도솔적예측식，병여현유문헌보도적결과진행료비교，발현당전결과정현료공극결구수궤성대재료유효열도솔적영향，여ORNL실험결과경문합。
Porous foam is a novel functional material, which have low density, high specific surface area and particular performance. However, porous foam is always heterogeneous, the distribution of pore structure is random. In this study, a random parameter, pore uniformity U, is proposed to study the thermal conductivity of heterogeneous porous foam and analyze the influence of pore uniformity on its effective thermal conductivity based on graphite foam. Numerical results show that the thermal conductivity of porous foam material decreases with the increase of the randomness of pore structure. A relationship between pore uniformity, porosity and thermal conductivity of heterogeneous graphite foam is proposed and compared with those in literature. The present results are in reasonable agreement with the measured data of ORNL and reflect the influence of pore structures.