Numerical calculation of effective thermal conductivity for complex multiphase materials

In this paper, the effective thermal conductivity (ETC) of porous medium which combined heat conduction and radiation was investigated numerically. In order to reflect the actual structure of porous media, a kind of reconstruct technique named Random generate-growth method (RGGM) was introduced to generate stochastic structure of porous media. Then Discrete Ordinate Method (DOM) and Finite Volume Method (FVM) were used to solve the coupled conduction and thermal radiation, and material's effective thermal conductivity was calculated. Based on the stochastic structures and numerical model, the effects of extinction coefficient, volume fraction of dispersed phase and temperature on heat transfer in porous media and its effective thermal conductivity were investigated. The results were well agreed with the theoretical calculated values, which demonstrates that the model presented in this paper is reliable for practical applications.