International Journal of Heat and Mass Transfer, Vol.47, No.23, 5129-5137, 2004
Effects of void-induced convection on interface morphology and segregation during low-g solidification
Recent microgravity experiments have been hampered by convection caused by unwanted voids and/or bubbles in the melt. In this work, a numerical model is developed to describe how thermocapillary convection generated by a void can affect a typical Bridgman solidification process in microgravity. The model is based on the quasi-steady Navier-Stokes equations for a Newtonian fluid coupled with the conservation equations for transport of energy and species. Numerical solutions for a variety of operating conditions indicate that void-generated thermocapillary convection can have a drastic effect on both interface morphology and solutal transport. (C) 2004 Elsevier Ltd. All rights reserved.
Keywords:solidification;microgravity;materials processing;segregation;thermocapillary convection;bubbles;numerical modeling