The effect of a magnetic field on transport phenomena in a Bridgman-Stockbarger crystal growth

Abstract

A mathematical formulation and computed results are presented to describe the temperature, velocity and tracer distribution in a Bridgman-Stockbarger crystal growing system, as affected by an externally imposed magnetic field. The computed results have shown that while the temperature profiles will not be significantly affected by the magnetic field, both the concentration fields and the velocity fields may be markedly influenced, especially at high values of the magnetic interaction parameter. In essence the imposition of a magnetic field will tend to both slow down the melt velocities and also modify the nature of the circulation pattern. Additional important effects of the magnetic field include its influence on the local and mean values of the heat and mass transfer rates at the melt solid interface. It was found that intermediate values of the magnetic interaction parameter (i.e. magnetic fields) would tend to provide the most uniform local heat transfer rates. While the velocities and mass transfer rates are damped by the magnetic field, the local value of mass transfer coefficient were the most uniform in the absence of an external magnetic field.