Heat transfer phenomenology of a hydrodynamically unstable melting system

An experimental study was conducted on a melting system consisting of a liquid layer overlying a solid substrate. The liquid and solid when molten were mutually miscible. To initiate melting, the liquid was heated by a heater grid suspended above the liquid-solid interface. Systems with the density of the liquid less than that of the molten solid were gravitationally stable, whereas those with the density of the liquid greater than that of the molten solid were gravitationally unstable. Total mixing of the melt layer and the liquid layer resulted in thermal mixing of the liquid. The heat transfer coefficient was found to be an increasing function of the density ratio of liquid and melted solid; this increase occurred in four stages. There was a marked enhancement of heat transfer in the system. The melting rate was also found to depend on temperature difference and conduction depth