Soret and Dufour effects on MHD convective heat and mass transfer of a power-law fluid over an inclined plate with variable thermal conductivity in a porous medium

A numerical model is developed to study the MHD mixed convection with the combined action of Soret and Dufour on heat and mass transfer of a power-law fluid over an inclined plate in a porous medium in the presence of variable thermal conductivity, thermal radiation, chemical reaction and Ohmic dissipation and suction/injection. The governing boundary layer equations for momentum, energy and species mass diffusion are transformed to a set of nonlinear ordinary differential equations by using similarity solutions which are then solved numerically based on shooting method with Runge–Kutta Fehlberg integration scheme over the entire range of physical parameters with appropriate boundary conditions. The influence of inverse Darcy number, Soret number and Dufour number, chemical reaction parameter, thermal Grashof number and solutal Grashof number on velocity, temperature and concentration fields are studied graphically. Finally, the effects of related physical parameters on local skin-friction, local Nusselt number and local Sherwood number are also studied. Results showed that the temperature and concentration fields were influenced appreciably by the Soret and Dufour effects.

► Increase in the inverse Darcy number decreases the velocity profile. ► Increasing the inclination angle leads to increase in the velocity profile. ► Effect of Eckert number and radiation decrease the temperature profile. ► Temperature profile increases with the increase in Dufour number. ► Soret effects are to decrease the concentration distribution.