ENTHALPY-POROSITY TECHNIQUE FOR MODELING CONVECTION-DIFFUSION PHASE CHANGE: APPLICATION TO THE MELTING OF A PURE METAL

TLDR

The enthalpy‑porosity technique enables fixed‑grid solutions of coupled momentum and energy equations without variable transformations. The study employs a two‑dimensional dynamic model to investigate how laminar natural‑convection flow affects the melting of pure gallium in a rectangular cavity. The enthalpy‑porosity method was applied on a fixed grid to simulate coupled convection‑diffusion phase change in the cavity. Numerical predictions for gallium melting using this approach agree excellently with experimental data, converge rapidly, and accurately capture melt‑front position and morphology, validating the technique for isothermal phase‑change modeling in metallurgical systems.

Abstract

The melting of pure gallium in a rectangular cavity has been numerically investigated using the enthalpy-porosity approach for modeling combined convection-diffusion phase change. The major advantage of this technique is that it allows a fixed-grid solution of the coupled momentum and energy equations to be undertaken without resorting to variable transformations. In this work, a two-dimensional dynamic model is used and the influence of laminar natural-convection flow on the melting process is considered. Excellent agreement exists between the numerical predictions and experimental results available in the literature. The enthalpy-porosity approach has been found to converge rapidly, and is capable of producing accurate results for both the position and morphology of the melt front at different times with relatively modest computational requirements. These results may be taken to be a sound validation of this technique for modeling isothermal phase changes in metallurgical systems.