Low frequency wave at the meniscus of a continuous caster generated by a DC magnetic field

J. Etay - Y. Delannoy

CNRS-INPG EPM-Madylam, BP 95, 38402 St Martin d'Heres Cedex, France }

Abstract
A continuous casting system for steel has been studied under a continuous magnetic field with the help of physical and numerical models. The behaviour of the free surface and the internal flow has been investigated experimentally on a mercury model, representing at the scale one third a typical casting head. A specific numerical model has been used to describe the effect of the horizontal magnetic field on the mean flow. For experiments with a magnetic field, a wave was observed at the mercury surface, travelling from one side of the mould to the other. With the help of a numerical model, this low frequency instability was related to the recirculating flow created by the nozzle. An analysis is proposed, based on the bidimensionalisation generated by the magnetic field and by self sustained oscillations of the upper recirculating flow. All other fluctuations of the free surface level are damped by the magnetic field. Tables 2, Figs 5, Refs 8.