FINITE-ELEMENT SIMULATION OF COMBINED BUOYANCY AND THERMOCAPILLARY DRIVEN CONVECTION IN OPEN CAVITIES

Thermocapillary-induced and buoyancy-driven convective flows that comm only occur in crystal growth are numerically simulated using Galerkin finite element method. The physical domain comprises of a open cavity with aspect ratio one and differentially heated vertical walls. The to p gas-melt interface is free to deform subject to 90 degrees contact a ngle boundary conditions at the two vertical walls; The unsteady two-d imensional Navier-Stokes equations are discretized in time using Chori n-type splitting scheme and pressure is determined from the Poisson's equation. The free surface is taken to be resting on vertical spines a nd its evolution in time is determined from the kinematic free surface equation. The governing equations for heat and momentum are solved in the Arbitrary Lagrangian Eulerian frame of reference to handle the mo ving boundary. The influence of Grashof number, Marangoni number, Bond number, Ohnesorge number and Prandtl number on the flow field and hea t transfer is investigated.