MHD non-Darcy mixed convective diffusion of species over a stretching sheet embedded in a porous medium with non-uniform heat source/sink, variable viscosity and Soret effect

The effects of temperature dependent viscosity and non-uniform heat source/sink on non-Darcy MHD mixed convection boundary layer flow over a vertical stretching sheet embedded in a fluid-saturated porous media is studied in this paper. Boundary layer equations are transformed into ordinary differential equations using self-similarity transformation which are then solved numerically using fifth-order Runge–Kutta–Fehlberg method with shooting technique for various values of the governing parameters. The effects of variable viscosity, porosity, electric field parameter, non-uniform heat source/sink parameters, Soret number and Schmidt number on concentration profiles are analyzed and discussed. Favorable comparisons with previously published work on various special cases of the problem are obtained. Numerical results for variation of the local Sherwood number with buoyancy parameter, Schmidt number, and Soret number are reported graphically to show some interesting aspects of the physical parameters.

► The effects of non-uniform heat source/sink parameter and electric field parameter on concentration profiles are obtained.
► The effect of Schmidt number is to decrease concentration distribution and solutal boundary layer.
► The effect of space-dependent heat source/sink parameter is to decrease concentration profile in the boundary layer.
► The effect of increase in the value of electric field parameter is to decrease concentration profiles.
► The effect of increase porosity of the porous medium is to decrease concentration profiles.