Simulation of Melting of a Pure Substance Using Curvilinear Moving Grids

ABSTRACT: Melting and solidification of metals play an important role in material processing, metallurgy, welding, and growth of crystals from melts and solutions. There are generally two types of methods to simulate the melting/solidification processes: 1) The fixed grid methods 2) Moving grid methods. In the fixed grid approach a fixed grid is used in the real space of the problem and the solid-liquid interface is accounted for by using artificial source terms similar to the flow in porous media. In this method the interface position is not tracked but can be estimated indirectly and approximately. In the moving grid method the flow equations in the curvilinear moving plane are transformed into the fixed computational plane. Consequently, the solution of the transport equations as well as the position of the interface is tracked accurately. In this work Stefan condition is explained and mathematical modeling and numerical prediction of phase change processes of pure materials using curvilinear moving grids at macroscopic level is presented. The effectiveness of the method is demonstrated by adopting the conventional problem of Gallium melting. Grid refinement test is carried out and effects of different time steps as well as various Rayleigh and Stefan numbers are examined on the results. ……………………………………………………………………………………………………………………………………………………………………………………………………………………