Melting Around a Migrating Heat Source

The problem of melting around a moving heat source arises in many different situations such as nuclear reactor technology (i.e., “self-burial” process of nuclear waste materials and reactor core “melt-down”), process metallurgy, and geophysics. Experiments were undertaken with a horizontal cylindrical heat source that melted its way through a phase-change material (n-octadecane) under its own weight. The heat source velocity and solid-liquid interface motion for a constant surface temperature source were measured. Effects of heat source density and surface temperature as well as the effects of the initial subcooling of the solid were investigated and are reported. The flow structure in the melt was visualized using a dye. Timewise variation of temperature distribution in the solid and the melt were also measured and are discussed. Results for the heat source migration velocity and the volume of the material melted are correlated in terms of the relevant problem parameters.