AN IMPROVED MATHEMATICAL-MODEL FOR ELECTROMAGNETIC CASTERS AND TESTING BY A PHYSICAL MODEL

The paper describes a physical model aimed at studying two important phenomena in electromagnetic (EM) casting of aluminum: the support of the molten metal pool and stirring caused by EM forces. The physical model is used both to test an improved mathematical model for EM casting and to provide insight into the effect of design changes on the two EM phenomena. Examples of design changes are changes in inductor current and position and screen position. The improved mathematical model, a two-dimensional (2-D) (axisymmetric) one, constrains the melt surface at the solidification line and neglects (with justification) buoyancy, surface tension, and the impact of flow on meniscus shape. The physical model was a cylindrical one where the solidified metal was simulated by a 248-mm-diameter aluminum bronze cylinder and the molten metal by Wood's alloy. Measurements were made of electric field, magnetic field, meniscus deformation, and velocities for the two types of caster in commercial use. Generally, good agreement was obtained between the mathematical model and the experimental measurements.