Effect of Lewis number on mixed double-diffusive convection in shallow rectangular cavities with double-lid-driven boundaries filled with non-Newtonian power-law fluids

This paper reports an analytical and numerical study of double-diffusive mixed convection in a non-Newtonian power-law fluid contained in a double lid driven horizontal rectangular enclosure submitted to uniform heat and mass fluxes along its short vertical sides, while the horizontal ones are insulated and impermeable. The first part from this study is devoted to the numerical solution of the governing equations, and the effect of the governing parameters, namely, flow behavior index for a power law fluid at the reference temperature and Lewis numbers, is examined. In the second part, an analytical solution, based on the parallel flow approximation in the case of a shallow cavity A ≫ 1, is proposed and a good agreement is found between the two types of solutions.