Melting of frozen, porous media contained in a horizontal or a vertical, cylindrical capsule

Melting of ice in porous media has been investigated experimentally and analytically for a horizontal and vertical cylindrical capsule. Quantitative results of the temperature distribution and solid-liquid interface motion and shape were obtained for inward melting with different size and types of spherical beads used as the porous media. Predictions from an analysis which considers conduction as the only mode of heat transfer in both the solid and liquid were compared to experimental data to show where natural convection becomes significant. It was found that the melting rate was augmented by natural convection in the liquid. For large differences in the thermal conductivity of the phase-change material and porous medium (e.g. water and aluminum), the effective thermal conductivity of the system was not predicted accurately by the model used, resulting in a further discrepancy between data and predictions. Moreover, the assumption of local temperature equilibrium between the void constituent and the porous medium becomes invalid for a water-aluminum bead system.