Phase field theory of liquid phase separation and solidification with melt flow

György Tegze1, László Gránásy1,2

1Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest H-1525, Hungary
2BCAST, Brunel University, Uxbridge, Middlesex, UB8 3PH, United Kingdom

A phase-field theory of binary liquid phase separation and solidification coupled to fluid flow is presented. The respective equations of motion and Navier-Stokes equations are solved numerically. We incorporate composition and temperature dependent capillary forces. The free energies of the bulk liquid phases are taken from the regular solution model. In the simulations, we observe Marangoni motion of the droplets, and direct and indirect hydrodynamic interactions between the droplets. We observe that capillary effects dramatically accelerate droplet coagulation and that solidification interacts with liquid phase separation.