Thermal buoyancy driven convection without surface tension effects is numerically investigated in a system with two immiscible fluids of which interface is assumed to be flat and undeformable. The geometry investigated has a square cavity with horizontal adiabatic walls and vertical isothermal ones differentially heated. This study is aimed at investigating the effects of parametric variations of the two fluid properties and interface-related conditions including no-slip interfaces with conduction and insulation on the interior phenomena.
The flow patterns and heat transfer characteristics in a cavity are mainly affected by the temperature distribution at the interface which causes heat transfer from bottom fluid to top one. Although the overall heat transfer rate is reduced in comparison with that of the insulated interface, local heat transfer rate is enhanced in the vicinity of cold wall in the top fluid and hot wall in the bottom one. The secondary circulation induced by the conflict of main flows of each fluid near the interface is related to Grashof number, Prandtl number, dynamic viscosity, and thermal conductivity. As a result of comparison with the no-slip interface with conduction, it is shown that the heat transfer through the interface is decreased by the secondary circulation of top fluid and increased by that of bottom one.
