Soret and Dufour effects on free convection boundary layers over an inclined wavy surface in a porous medium

The problem of free convection boundary layer flow near an inclined wavy surface in a fluid saturated porous medium with Soret and Dufour effects has been solved using boundary layer approximations. A suitable coordinate transformation is used to transform the complex wavy surface to a smooth surface, and the obtained boundary layer equations are solved by the cubic spline collocation method. Effects of Soret parameter, Dufour parameter, angle of inclination, Lewis number, buoyancy ratio, and wavy geometry on the heat and mass transfer characteristics are studied. Results show that increasing the Soret parameter leads to a greater fluctuation of the local Nusselt number with the streamwise coordinate and a smaller fluctuation of the local Sherwood number with the streamwise coordinate. Moreover, as the Dufour parameter increases, the fluctuation of the local Sherwood number with the streamwise coordinate is enhanced, while the amplitude of fluctuation of the local Nusselt number with the streamwise coordinate is reduced. An increase in the Dufour parameter tends to decrease the dimensionless total heat transfer rate while an increase in the Soret parameter tends to decrease the dimensionless total mass transfer rate.