气孔形状与取向对水泥基多孔材料导热系数的影响研究

Effect of Pore Shape and Orientation on the Thermal Conductivity of Cement-based Porous Materials

基于随机算法和实测孔结构数据,发展了不同气孔形状与取向的水泥基多孔材料代表性体积单元模型,结合voxel网格和周期性边界条件,研究了多孔材料气孔形状与取向对保温隔热性能的影响。结果表明:水泥基多孔材料的气孔形状越偏离球形,材料导热系数越小,当气孔纵横比为0.5时,导热系数下降了0.015 W/(m·K);当气孔纵横比为0.5的椭球孔的极轴沿同一方向排列时,沿气孔极轴方向的导热系数减小了22.1%。

Based on random algorithm and measured pore structure data,representative volume element models of cement-based porous materials with different pore shapes and orientations were developed.By combining voxel grids and periodic boundary conditions,the influence of pore shape and orientation on the thermal insulation performance of porous materials was studied.The results show that the more deviated the shape of the pores in cement-based porous materials from spherical,the smaller the thermal conductivity of the material,when the aspect ratio of pores is 0.5,the thermal conductivity decreases by 0.015 W/(m·K).When the polar axes of all elliptical pores with an aspect ratio of 0.5 are aligned along the same direction,the thermal conductivity along the pore major axis direction decreases by 22.1%.