MODELLING OF CONVECTION-DOMINATED MELTING IN RECTANGULAR ENCLOSURES

Abstract

A validated CFD by ANSYS model is built for a melting process of PCM (gallium), inside rectangular enclosure heated from one side and cooled from another. This was carried out by enabling the solidification and melting model in addition energy model of ANSYS. Regression model of melting front results from CFD model by ANSYS is utilized and integrated inside numerical approach by MATLAB to generate constants for Nusselt correlations and effective conductivity during different melting stages that can be used to define melting front locations and temperature at grid different locations. In addition, effect of the wall temperature and model aspect ratio variation on melting process have been simulated by ANSYS and analyzed in details. Enthalpy method and conduction equations for 2-D model were used to describe the predicted share of convection in melting process, with trial and error by assuming the constants automatically. Accordingly, melting process can be predicted in a simple and a conservative time way at the same time, the results are mainly indicating that convection heat transfer affects the melting process and melting behavior which is in coherence with previous experimental and analytical literature. Also, the effect of aspect ratio were investigated to assure that the more the aspect ratio, the better is the temperature homogeneity.