Development and validation of a numerical model for frost growth based on nucleation theory

Cold surface frosting is a complex process involving multi-component phase change heat and mass transfer and variable void structure. It is very challenging to deeply understand the frosting law and mechanism and accurately simulate the frosting process. Existing numerical models of frost growth have many shortcomings, such as a narrow application range, few verification parameters and low reliability. For these reasons, this paper developed a numerical model of frost layer growth based on nucleation theory, modified the phase transition model, and proposed a formula for constraining the picking limit of the frost layer. Additionally, it introduced a formula for calculating the average temperature of the two phases in the frost layer. The simulation results for frost layer thickness, density, temperature, and distribution were extensively verified using experimental data obtained by different scholars under various conditions and compared with simulation results in related literatures. The results show that the simulation results of all parameters under different conditions are in good agreement with the experimental data, with a maximum deviation of less than 15 %. Notably, the simulation results for frost thickness and distribution are more accurate than those found in existing literatures. The model developed in this paper offers a higher number of validation parameters, a wider validation range, and greater accuracy and reliability. This model can provide a solid theoretical foundation for studying frost characteristics under complex conditions and for the optimal design of frost-prone heat exchangers.