Mixed convective flow of immiscible viscous fluids in a vertical channel

Abstract

Combined free and forced convection flow in a parallel-plate vertical channel is analyzed for immiscible viscous fluids taking into account the effect of viscous dissipation. Three types of thermal boundary conditions are described. These thermal boundary conditions are isothermal-isothermal, isoflux-isothermal, and isothermal-isoflux for the left-right walls of the channel. The coupled nonlinear governing equations are solved analytically using the regular perturbation method. Separate solutions are matched at the interface using suitable matching conditions. The results are represented graphically for various governing parameters such as the ratio of Grashof number to Reynolds number, viscosity ratio, width ratio, and conductivity ratio for equal and different wall temperatures. It is found that the viscous dissipation enhances the flow reversal in the case of a downward flow while it counters the flow in the case of an upward flow. © 2010 Wiley Periodicals, Inc.