Numerical Analysis of Double-Diffusive Convection/Solidification Under g-Jitter/Magnetic Fields

Abstract

A e nite element model is presented for the g-jitter induced double-diffusive convection and solidie cation phenomena with and without the presence of magnetic e elds in an Sn-doped Bi crystal growth system planned for space experiments. The model is developed based on the deforming e nite element formulation with the penalty formulation forpressure approximation. An isothermalfront tracking algorithm is used to predict thesolid‐ liquid interface. Extensive numerical simulations are carried out and parameters studied include the solute concentration dependent melting temperature and magnetic e eld strength under both steady state and g-jitter conditions. Both synthesized g-jitter and real g-jitter data taken from space e ights are used. Computed results show that the concentration effects on interface morphology must be considered for an accurate prediction of solidie cation interface morphology, and g-jitter can induce signie cant convective e ows in the liquid pool, which, in turn, cause solute concentration nonuniformity during the space crystal growth. The use of an applied magnetic e eld can be effective in suppressing the deleterious g-jitter induced convection and solute nonuniformity and their effects on solidie cation.