MOMENTUM EQUATION FOR DENDRITIC SOLIDIFICATION

Abstract
For analyzing dendritic solidification, convection in the mushy zone is based on a momentum equation for a porous medium with a spatially varying fraction of liquid. Results are compared with those obtained with a less complete momentum equation. Calculations are done for directional solidification, with isotherms and isoconcentrates that move with a constant velocity. Thermosolutal convection as a function of time is studied by perturbing the solutal field. The total kinetic energy, the nature of the convection cells, and the isoconcentrates are significantly different for the two models. Hence the complete form of the momentum equation should be used