Numerical Simulation Of A 2D Crystal Growth Problem: Latent Heat Effects And Solid-liquid Interface Morphology (original) (raw)

The influence of latent heat and natural convection in the melt and the shape of the melt-crystal interface are analyzed for a vertical Bridgman crystal growth system by direct numerical simulation. The temperature and the velocity field in the melt and in the crystal are computed using an homogenization technique. Initially the ampoule contains poly-crystal material, these container is translated inside a furnace which includes two heating zones characterized by two temperatures which are respectively greater and lower than the melted temperature of the material. The two heating zones in the furnace are separated by an adiabatic zone when the solid-liquid phase change occur. The control of the solidification conditions (phase change front velocity, gravity ...) permits to produce with these technique very high quality single crystals. The results presented in this paper show the effects of various gravitational conditions upon the flow in the melted part of the material inside the ampoule. We have also analyzed the effect of the latent heat upon the shape of the melt-crystal interface and the convective cells in the melted pool.