ANALYSIS OF NATURAL CONVECTION MELTING OF A SUBCOOLED PURE METAL

A numerical study is reported of melting of a pure metal inside a vertical rectangular enclosure with both natural convection in the liquid and conduction in the solid. A streamfunction/vorticity/temperature formulation is employed in conjunction with boundary-fitted coordinates for mapping the irregular shape of the moving solid-liquid interface. Twenty numerical experiments are conducted for Rayleigh numbers ranging from 8.99 ×: 104 to 1.44 × 106 and subcooling parameters ranging from 0.5 to 4.0. The results show that the combined effects of natural convection in the melt and subcooling of the solid considerably affect the melting of a pure metal. Subcooling significantly reduces the melting rate and leads to a steady state for which the position and the shape of the solid-liquid interface are dictated by the subcooling parameter and the Rayleigh number. A correlation is proposed for the heated-wall Nusselt number at steady state as a function of the Rayleigh number and the subcooling parameter.