Numerical Modeling of Melt Flow and Mixing in an Inductively Stirred Ladle and Comparison with Gas and Mechanical Stirring

Abstract

Fluid flow and mixing in an inductively stirred ladle are modeled mathematically. The effect of two modes of electromagnetic stirring on motion is simulated; one produces a predominantly swirling motion (as in mechanical, paddle‐stirred ladle), while the other generates an upwelling, toroidal motion (as in gas‐stirred ladle). Two different ANSYS software programs, namely, Maxwell‐3D and Fluent, are applied to carry out numerical simulations. In the former, 3D Maxwell's equations are solved to estimate, a priori, the distribution of Lorentz force within the melt phase due to the imposed three‐phase, alternating current excitation of copper coils, while in the latter, time‐averaged magnetohydrodynamic (MHD) turbulent flow equations are solved to yield the electromagnetically driven flow field. Model predictions are validated against published results and it is shown that the electromagnetic as well as turbulent‐MHD models developed in this work are robust and perform sufficiently accurately. Finally, numerically predicted results together with relevant published work indicated that at equivalent specific input stirring power and identical vessel shape and volume, mixing is fastest in electromagnetic stirring with a traveling magnetic field (producing an upwelling toroidal motion), followed by mechanical agitation, gas stirring, and electromagnetic stirring with a rotating magnetic field (inducing swirling flow).