Study of frosting on a cryogenic surface from a perspective of thermal resistance analysis

Frosting researches under cryogenic conditions have great significance in liquefied natural gas (LNG) and aerospace applications. The investigation on the thermal resistance and the surface temperature of the frost layer is indispensable but insufficient due to the difficulty in experimental measurements. A novel computational fluid dynamics (CFD) model considering the change of the frost layer thermal conductivity was developed for the thermal resistance analysis of the frosting process of water-vapor-carried gas flowing over a cryogenic surface, and the change of the frost surface temperature over time was predicted. The calculated results were validated against the published experimental data and showed good agreements. Based on the validated model, the overall variation and local distribution of the thermal resistance and the surface temperature of the frost layer, as well as the growth behaviors, were studied. Furthermore, the influences of principal operating parameters on the averaged thermal resistance and the averaged surface temperature of the frost layer were analyzed, including the cryogenic surface temperature, the inlet gas flow temperature, the water vapor content of the inlet gas flow and the velocity of the inlet gas flow. Parameter sensitivity analysis was carried out and the averaged thermal resistance of the frost layer shows greatest sensitivity to the inlet gas flow temperature.