Study of Melting of a Horizontal Ice Layer with a Combined Effect of Temperature and Concentration

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Experimental and numerical investigations are carried out of the melting of a horizontal vertical ice plate into a calcium chloride aqueous solution inside a square cavity. The ice plate immersed into the aqueous solution melts spontaneously associated with temperature depression in the ice even when there is no temperature difference between the ice and the aqueous solution just beginning of the melting, which is not possible to predict through the classical Stefan problem controlled with a thermal diffusion. A numerical method with a new concept of a mass diffusion controlled melting predicts quantitatively an abrupt depression in the temperature of the ice, a transient melting mass, and a double diffusive convection in the liquid. The melting amount from above melting surface is about double larger than that from below due to the concentration induced predominant convection. The numerical results for the melting from below predicts well the experiment, however, predicts less about 40% compared with the experiment. The present numerical treatment based on the laminar assumption is difficult to predict the melting amount from above melting surface since it appeared a very small spouts induced with the buoyancy like a salt finger on the melting surface. Moreover, it is also found that the present numerical prediction will require to set a very smaller mesh size less than about 0.1mm due to the very thin concentration boundary layer closest to the melting front.