2009 年 26 巻 1 号 p. 25-33
In this paper, we investigated experimentally the growth of frost layer under natural convection to obtain effects of conditions related to air and cooling surface. We compared the results with numerical calculations, which are based on a non-homogeneous frost layer growth model used in the study of the forced convection. The comparison showed that the trend of the numerical results for the frost layer growth is in good agreement with the experimental results. The growth of the frost layer is markedly influenced by the thermal conductivity of the frost layer. The present numerical calculations suggest a thermal conductivity for the frost layer that is twice the value predicted by Yonko-Sepsy relationship. An accurate evaluation of the thermal conductivity of the frost layer is necessary to be able to match the frost layer thicknesses with those of the experiments. The present numerical model has the potential as a tool for the systematic investigation of influences of various factors affecting the frost phenomenon.