A semi-empirical correlation for the frost density

• A semi-empirical correlation for the frost density is put forward.
• The theoretical analysis shows the frost porosity obeys the t scale.
• The frost density model depends on the time and also on the modified Jakob number.
• The model is able to predict the experimental data with errors within a ±10% band.

A first-principles model for predicting the evolution of the porosity of a frost layer over time was advanced. The theoretical model was used together with experimental data obtained elsewhere to put forward a semi-empirical correlation for the frost density as a function of the time, and the modified Jakob number, which carries information about the thermodynamic conditions of the air stream and the chilled surface. When compared to experimental data, the proposed correlation showed errors within ±10% bounds. Comparisons with other frost density correlations available in the open literature are also reported.