Numerical analysis on the enhancement of molten steel stirring by magnetic field strength control

Abstract

The objective of the current work is numerical investigation on the idea of magnetic field strength control in an electromagnetic stirring (EMS) process to enhance molten steel stirring. We expect that a time-periodically perturbed magnetic field enhances the turbulent kinetic energy of the flow in an EMS system and makes more uniform inclusion distribution. In the current study, we suggest an optimization strategy for finding an optimal excitation frequency of magnetic field that maximizes stirring effects. We use nonlinear dynamics theory to find the optimal frequency for enhancement of stirring. We also perform numerical simulations to show that enhancement effect is indeed obtained at that frequency. The optimal frequency, for enhancement of turbulent kinetic energy and uniform inclusion distribution, has been found between the two resonant frequencies of the primary and the secondary rotational flow. (C) 2012 Elsevier Ltd. All rights reserved.