介孔复合材料声子输运的格子玻尔兹曼模拟

Lattice Boltzamn model of phonon heat conduction in mesoporous composite material

采用格子玻尔兹曼方法对NaCl@Al2O3介孔复合材料内的声子热输运进行了模拟分析.基于德拜物理模型,提出了温度耦合的复合材料界面处理方法,有效实现了复合材料声子输运的格子玻尔兹曼模拟,获得了不同孔径、孔隙率、孔形状、孔排列、界面条件系数下介孔复合材料的热导率,并进行影响因素分析.结果表明:该介孔复合材料热导率,在孔隙率一定时,随着孔径增大而增大,呈现显著的尺度效应;在孔径一定时,热导率随孔隙率增大而减小;孔径和孔隙率一定时,热导率随界面条件系数的增大而减小;孔形状和孔排列均会影响介孔复合材料的热导率,且这种影响会随着界面条件系数的增大而增大.

In this paper, lattice Boltzmann method is used to simulate the phonon heat transport in NaCI@A1203 mesoporous composite material. Based on the Debye model, temperature coupling method is first proposed in the thermal simulation of mesoporous composite material, to calculate the effective thermal conductivity of mesoporous composite material with pores of various interface condition coefficient value, pore size, porositiy, shape and arrangement. Studies show that for the same porosity, the estimated thermal conductivity increases with increasing the value of diameter, showing the scale effect; for the same diameter, the estimated thermal conductivity decreases with increasing the value of porosity; for the same porosity and diameter, the estimated thermal conductivity decreases with increasing the value of interface condition coefficient p; porous shape and arrangement will affect thermal conductivity value, and the influences greatly increase with increasing the value of p.