Direct Numerical Simulation of Solidification Microstructures Affected by Fluid Flow

The e ects of uid ow on the solidi cation morphology of pure materials and solute microsegregation patterns of binary alloys are studied using a computational methodology based on a front tracking/ nite di erence method. A general singleeld formulation is presented for the full coupling of phase change, uid ow, heat and solute transport. This formulation accounts for interfacial rejection/absorption of latent heat and solute, interfacial anisotropies, discontinuities in material properties between the liquid and solid phases, shrinkage/expansion upon solidi cation and motion and deformation of the solid. Numerical results are presented for the two-dimensional dendritic solidi cation of pure succinonitrile and the solidi cation of globulitic grains of a Plutonium-Gallium alloy. For both problems, comparisons are made between solidi cation without uid ow and solidi cation within a shear ow.