Abstract:

The relationship between thermal conductivity of porous material and fractal dimension is numerically simulated by using finite element method. The solid matrix and pore space are generated randomly according to material porosity；and material parameters and element properties are changed by ANSYS parameter design language. The effective thermal conductivity is computed according to thermal flux through some section computed by FEM and Fourier heat transform law. The investigation shows that the effective thermal conductivity linearly decreases with increasing porosity; the effective thermal conductivity of FEM model will increase in exponential function with the increase of scaling factor while the material porosity is constant. The effective thermal conductivity will decrease in exponential function with the increase of fractal dimension of porosity space and increase in exponential function with the increase of fractal dimension of solid matrix

Key words: porous material, effective thermal conductivity, fractal dimension, random numerical simulation, FEM