Frost deposition in a parallel plate channel under laminar flow conditions

The subject of this paper is a theoretical and experimental study of frost formation on cooled parallel plates in laminar forced convection. In the experiments time variation of the frost layer thickness was measured at several locations downstream along the test section which was positioned in an open-loop wind tunnel. The parameters varied were air velocity (Reynolds number), air temperature, air humidity ratio, and plate temperature. The process was simulated numerically using a two-dimensional transient model based on the conservation equations of mass, momentum, energy, and species. The physical domain of interest was divided into two subdomains, one for the moist air stream between the plates (gaseous phase), and one for the frost layer (solid phase). The two sets of governing equations were coupled by boundary conditions at the moving interface which required an iterative solution strategy. With this approach, the local distribution of temperature and porosity in the frost layer, which is nearly impossible to obtain in the experiments, could be predicted at any time. The results of the total heat and mass transfer rates as well as the development of the local and average frost thicknesses were compared with the experimental findings.