Inward solid-liquid phase-change heat transfer in a rectangular cavity with conducting vertical walls

This paper reports basic solid-liquid interface and heat transfer data obtained during solid-liquid phase change (melting and solidification) of n-octadecane in a two-dimensional rectangular cavity with conducting vertical walls. The shadowgraph technique was used to measure local heat transfer coefficients at the heat source surface. The solid-liquid interface motion during phase change was recorded photo-graphically. During melting, a development of vortex motion at the bottom melt zone was observed to be quite similar to that in a rectangular cavity with isothermal walls. In both melting and solidification experiments the conducting walls acted as isothermal walls at the late times during the processes. Natural convection was found to control the melt shape, the melting rate and heat transfer during melting. The effect of the initial subcooling of the solid was also investigated and the results clearly showed that heat conduction was the dominant mode of energy transport during the inward solidification. For solid-liquid phase-change heat transfer short extended surfaces are more effective than longer ones.