Influence of a vertical magnetic field on convection in the horizontal Bridgman crystal growth configuration

L. Davoust¹ - R. Moreau¹ - R. Bolcato¹ - T. Alboussiere² - A. C. Neubrand² - J. P. Garandet²

¹ INPG Laboratoire EPM-MADYLAM, ENSHMG, BP 95 38402 Saint Martin d Heres Cedex, France
² Commissariat a l Energie Atomique DTA/CEREM/DEM/SES, Centre d Etudes Nucleares de Grenoble, 17 avenue des Martyrs, 38054 Grenoble Cedex 09, France

Abstract
This paper is a review of recent results on the MHD damping and reorganization of the convective flow present in the liquid pool of a horizontal Bridgman furnace during crystal growth. An asymptotic analysis, based on the assumption Ha " I and concerning the fully-established regime, predicts the distribution of velocity, electric potential, current density, and temperature within the core for any cross-section shape. Numerical results obtained for 0 <. Ha < 100 complement this asymptotic theory and show how the typical MHD flow organisation with cores, Hartmam layers, and side layers, builds up as Ha increases. And an experiment, using mercury to model the liquid pool, and equipped with 55 thermocouples, allows us to check these predictions. It also complements she theory, namely on the stabilizing influence of the magnetic field and on the flow in the end regions.