A numerical investigation into frost formation under impinging flow conditions

Abstract

Frost formation is an undesired phenomenon for a wide range of practical applications as it diminishes amount of heat dissipation from heat transfer regions. In this paper, frost growth process on a vertically suspended plate is numerically investigated. Modeling of a frost structure is a multifaceted task since contribution of mass and heat transfer effects must be considered simultaneously. An Eularian-Eularian multiphase-multicomponent model is used and source terms are added to conservation equations in order to generate frosting phase change process. The model implemented herein is able to predict frost deposition on a surface under impinging flow conditions. Computational domain is formed of two separate phases which are humid air and frost phases. Humid air phase is also consisted of dry air and water vapor, latter is transformed into frost layer by means of introduced source terms. Experimental results were used to validate the numerical approach. Results showed a good agreement with the frost thickness growth observed during the experiments. Predicted temperature and density variations inside the porous frost layer were discussed. Frost thickness increased rapidly at the beginning of the experiments; later rate of increase is decreased. Denser frost layers obtained adjacent to the frosting surface. Temperature within the frost layer is dropped during the growth process.