Melt Convection effects in the Bridgman crystal growth of an alloy under microgravity conditions

摘要

The solidification of a dilute alloy (bismuth-tin) under Bridgman crystal growth conditions is investigated in support of NASA's MEPHISTO space shuttle flight experiment.Computations are performed in two-dimensions with a uniform grid.The simulation includes the species-concentration,temperature and flow fields,as well as conduction in the ampoule,Fully transient simulations have bene performed; no simplifying steady state approximations are used.Results are obtained under microgravity conditions for pure bismuth,and Bi-0.1 at.