COMPUTER-SIMULATION OF HEAT-TRANSFER, FLUID-FLOW, AND INTERFACES IN AFLOATING MOLTEN ZONE - A HALF-ZONE CONFIGURATION

The finite volume method with an implementation of Newton's scheme is used to study steady heat transfer, fluid flow, and interfaces in a fl oating molten zone that is set up between a heating rod and a sample r od, i.e., the so-called half-zone system. Stream function/vorticity an d temperature formulation of the Navier-Stokes equation, the energy eq uation, and their associated boundary conditions are written in genera lized curvilinear coordinates and conservative-law form with Boussines q approximation. Sample calculations are reported for sodium nitrate, a high-Prandtl-number material (Pr=9.12). Both natural convection and thermocapillary flow in the molten zone, as well as unknown interfaces and an overall mass balance constraint, are considered. The effects o f heating temperature, gravity, and surface tension gradient on the fl ow patterns and interfaces are illustrated through computer simulation .