In the present paper,onedimensiona1freezing process of an aqueous solution of sodium chloride,and melting process of the frozen solution were studied experimentally and analytically. A numerica1 analysis was performed,considering a mass diffusion within the mushy region which is a heterogeneous materia1including the solid phase and the liquid phase. The distribution of the temperature,the position of freezing or melting front and the average solid fraction in the mushy region were measured,varying a few parameters such as initial temperature,and initial concentration and the temperature of the cooling wall. Especially, an experiment for the case of the concentration above the eutectic point was inc1uded. The infuluences of the above parameters on the freezing and me1ting processes were clarified. The experimental results were compared with the analytical results. From close agreement between both results,it was shown that this analysis was effective. Besides,by the present analysis,it was clear that the influence of flow caused by the difference between the density of the liquid and that of the solid,on the temperature field,was very small. At last,it was shown by the present analysis that a mass diffusion in the mushy region affected the distribution of concentration in the liquid region,after the growth of freezing front stopped.
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