Modeling of Thermal Conductivity of Moist Materials

Abstract

Thermal conductivity of moist, porous materials was analyzed. A new formula for thermal conductivity of these materials was derived which accounted for form of moisture present either as a thin film around the grains, liquid droplets or meniscus between the neighboring grains. During derivation of the formula it was assumed that the granular medium is made of randomly distributed spherical grains which can appear in a loose, unconsolidated form or can be fused with other grains to form consolidated medium. It was found that thermal conductivity of the moist material is not only depended on thermal conductivities of the constituents, porosity of medium and water content but also on the mean coordination number of the medium, degree of consolidation of a skeleton made from grains and form in which the moisture appeared. The predicted thermal conductivity was compared to some experimental data and a good correspondence of the thermal conductivity was observed