Natural convection from a vertical plate immersed in a power-law fluid saturated non-Darcy porous medium with viscous dissipation and Soret effects

In this work, we study the viscous dissipation and thermal-diffusion effects on natural convection from a vertical plate embedded in a fluid saturated non-Darcy porous medium. The non-Newtonian behaviour of fluid is characterized by the generalized power-law model. The governing partial differential equations are transformed into a system of ordinary differential equations using a local non-similarity solution and the resulting boundary value problem is solved using a novel successive linearisation method (SLM). The accuracy of the SLM has been established by comparing the results with the shooting technique. The effects of physical parameters on heat and mass transfer coefficients for the convective motion of the power-law liquid are presented both qualitatively and quantitatively. The results show that the Nusselt number is reduced by viscous dissipation and enhanced by the Soret number but the Sherwood number increases with viscous dissipation and decreases with the Soret number. An increasing viscosity enhances heat and mass transfer coefficients in both cases of aiding buoyancy and opposing buoyancy. © 2014, African Mathematical Union and Springer-Verlag Berlin Heidelberg.