Melting of ice-aluminum balls system

Abstract

Melting of ice-porous media (aluminum balls) system contained in a rectangular test cell has been studied both experimentally and numerically. When the superheat across the liquid region was small, the flow in the porous media was weak and the interface was almost planar. For larger superheats, natural convection flow, the interface velocity, and shape were found to depend on the imposed temperature and the permeability of the porous medium. The measured temperature distributions were compared with the predictions of a numerical model that considered both conduction in the solid and natural convection in the liquid region. The model is based on volumetric averaging of the macroscopic transport equations, with phase change assumed to occur vvolumetrically over a small temperature range. Both Brinkman and Forchheimer extensions were added to the Darcy equations. The effect of density inversion of water on the fluid flow and heat transfer has been modeled. Reasonably good agreement has been found between the experimental data and numerical predictions. Heat conduction in the high thermal conductivity porous matrix was found to influence considerably the melting front shape and motion.