A Numerical Methodology for Convection-Diffusion Controlled Unconstrained Melting Problems
A numerical methodology is introduced to solve convection-diffusion controlled unconstrained melting problems. When melting and solidification of phase change materials are addressed by the enthalpy porosity method, the Darcy Source term inhibits the velocities obtained from the momentum equations, leading their values to reach zero on complete solidification. This limits the scope of the enthalpy porosity approach to constrained melting problems. A viscosity-porosity relation is derived based on Darcy Law to simulate the solid-liquid phase change. Appropriate momentum formulation for the proposed methodology is presented in the paper. The results from the proposed scheme are validated with the experimental results from literature involving unconstrained melting of phase change material (PCM). The results obtained are in good agreement with the experimental data. The proposed formulation is capable of simulating the melting of phase change materials (PCM) undergoing unconstrained melting