A Study on Frost Formation (On Dimensionless Parameters Correlating Density and Thickness of Frost Layer)

The observation of the frosting process in an early stage of the deposition revealed that, in the range of our experiments, the process begins with the condensation of water vapor on the wall in the form of supercooled liquid water droplets. From these observations, it was clarified that the frost density is affected by the number density of the frost nuclei and that the formation of frost nuclei depends on the heat and mass transfer conditions. Consequently, the dimensional analysis was carried out to find the dimensionless parameters which correlate the thermal conductivity of a frost layer. The experiental results of the density and the thickness of the frost layer were correlated fairly well by the parameters introduced by the dimensional analysis for the cases of frost formations on the vertical plate and the horizontal cylinders in an array in free convection