Mathematical modelling of AMF geometry and frequency impacts on volume and surface melt flows at induction melting

I. L. Nikulin

Perm National Research Politechnical University, Perm, Russia

Abstract
Convection in molten metal exposed to an alternating magnetic field is investigated numerically. Governing equations are written in an axial symmetric laminar approximation and include equations for the calculation of magnetic fields and eddy currents; the motion equations in the Boussinesq approximation take into account averaged time independent electrodynamic forces acting in conducting liquids; the heat transfer equation employs averaged Joule heat sources. The correctness and the applicability of the laminar axisymmetric model to describe turbulent heat and mass transfer in a magnetic field was proved by verification and comparison with physical experiment. The influence of buoyancy and alternating magnetic field generated forces on the generation of melt flows in the melt volume and at the surface is shown for different field geometries and frequencies. Results obtained in extreme cases are compared with results in the literature. The stability condition for oxide scab on the melt surface is described, the alternating magnetic field impacts on it are investigated. Ways to remove the oxide scab are suggested. Tables 4, Figs 9, Refs 26.