NUMERICAL SIMULATION OF ELECTROMAGNETIC MELTING AND EVAPORATION OF SPHERICAL METAL PARTS

ABSTRACT

A three-phase Stefan-like problem is formulated to solve simultaneous melting and evaporation of spherical metal particles placed in a uniform external alternating magnetic field. A front-fixing transformation and Galerkin finite element method are used in the solution to this problem of two moving boundaries. Numerical simulations show that for lower values of the initial particle radius R₀ and the amplitude of the external magnetic field B₀, the melting and evaporation processes can be separated without any significant loss of precision. For higher R₀, B₀ the solid-liquid and liquid-vapor interface velocities are of the same order of magnitude during most of the process, and a simultaneous solution is necessary. Comparison of results obtained by equilibrium and nonequitibrium evaporation models shows that in shorter time periods, up to 1 s, the equilibrium models with properly chosen vaporization temperatures can effectively simulate the behavior of nonequilibrium models.