Melting of Metals Driven by Natural Convection in the Melt: Influence of Prandtl and Rayleigh Numbers

The analysis of the melting process of a pure material from an isothermal vertical wall has motivated a significant number of experimental and numerical studies in the last ten years. When the only external field is gravity and if no capillary or solutal effects have to be taken into account, the melting process is controlled by thermally induced natural convection in the liquid phase. Most of the available experimental and numerical results have been obtained for the melting of phase-change materials (PCMs) with a high Prandtl number liquid phase. Detailed experimental results concerning melting of PCMs with a low Prandtl number (metals) have appeared only recently and comparisons with numerical solutions show qualitative agreement, but the influence of the governing parameters on the kinetics of the melting process has not been clearly analyzed. The purpose of this paper is to provide results on the heat transfer characteristics of the system over a wide range of Rayleigh and Prandtl numbers in the low Prandtl domain.