Effects of variable viscosity and periodic boundary conditions on natural convection double-diffusive flow past a vertical plate in a slip flow regime

This paper studies the effects of variable viscosity and periodic boundary conditions on natural convection double-diffusive flow past a vertical plate in a slip flow regime when suction velocity oscillates in time about a constant mean. The fluid viscosity is assumed to vary with temperature. The problem is governed by a nonlinear and coupled linear system of partial differential equations. Perturbation method is employed to solve the equations. The influence of flow parameters on fluid temperature, concentration and velocity, skin friction, and rate of heat transfer have been presented graphically. It is observed that increase in viscosity parameter for the binary mixture of carbon dioxide (Sc=0.94) in air (Pr=0.71) increase velocity near the plate. In addition, the mean skin friction increases with increase in viscosity parameter.