Numerical prediction of spatio-temporal frosting patterns of curved surface considering varying working parameters

Abstract

Accurate numerical prediction of frosting patterns is essential for the efficient layout and timing defrosting of heat exchangers under frosting conditions. In this study, a numerical model is developed to predict the spatio-temporal frosting habits on curved surfaces in combination with the correlations of frost density and thermal conductivity. In the model, frost melting is considered. After verification, the frosting and heat transfer characteristics along the flow path are investigated under various structural and operating conditions. Frost thickness along the path is mainly affected by the cooling surface temperature, while the heat and mass transfer rates are strongly correlated with the humidity ratio. The proportions of latent heat and sensible heat are distributed more unevenly in parallel flow case than in counter flow case. Frost deposition is facilitated by a smaller radius of curvature of the cooling surface. More uniform frosting characteristics along the path and smaller heat transfer obstruction are presented with a smaller length-to-height ratio of the flow path.