A finite difference model for computing thermal conductivity of granular materials

Abstract

A finite difference model for computing the thermal conductivity of granular materials is developed. The conventional two-dimensional finite difference equations for homogeneous single-phase medium are extended to the case of two-phase medium using the concept of equivalent thermal conductivity. The granular material is modelled by a two-dimensional finite difference mesh, wherein some of the control volumes are randomly assigned as voids. The proposed model is validated with existing experimental data and empirical formulas for different porosities and pore fluids. The results indicate that the model is adequate for two-phase media with (ks/kf) ratio less than 200, and applicable for most civil engineering materials. © 1992.