On the effective thermal conductivity of saturated porous media

Carefully quantified effective thermal conductivity measurements of saturated porous systems are reported. Solid-fluid Systems considered include glass-water, glass-air, steel-water, and steel-air. These systems yield solid-fluid conductivity ratios of 1.08, 25.7, 102, and 2400, respectively. The solid phases consist of 3.96 mm glass spheres and 14 mm steel ball hearings, which give mean porosities of 0.365 and 0.403. The experimental method is based on the transient heating of a semi-infinite cylinder by a constant heat flux at the boundary. The data reduction technique is unique because it avoids determining the effective thermal diffusivity and quantifying the boundary heat flux. In addition, particular attention is paid to assessing experimental uncertainty. Consequently, this study provides data with a degree of precision not typically found the literature. A complete accounting of energy storage and transport in the transient system is conducted to complement the uncertainty analysis. A thorough literature review is also presented to facilitate a critique of the experimental results.