A Study On The Effects Of Thermoelectric Magnetohydrodynamics In Front Of Dendrites

In the solidification with a magnetic field, both thermoelectric magnetohydrodynamic (TEMHD) effect and magnetogydrodynamic (MHD) effect exist simultaneously. The two effects have different influence on the fluid flow, leading to drive flow or brake flow. In this paper, a 2D model which is based on a combination of the Vc++ and the commercial finite volume package Fluent is proposed, for simulation of the magnetic driven fluid flow. This paper will focus on the relationship between TEMHD effect and MHD effect and how the thermoelectric magnetohydrodynamic effect affects the solidification process.The results have showed that when applied varying magnetic field, the flowing field changed differently because of the interaction between the TEMHD and MHD. When the magnetic field is less than 0.2 T, the TEMHD effect dominates the melt flow. However, as the magnetic field continue to increase, the MHD effect plays a dominant role in determine the flowing field in the mushy zone. The computed results correspond well to the experimental results. The temperature gradient in front of the liquid-solid interface also influences the flowing velocity, leading to the enhanced TEMHD effect. But when the magnetic field and temperature gradient are kept on a constant, growth rate has no significant impact on the flow velocity in the mushy zone.