In this paper, we discuss the effect of non-linear density temperature relation on mixed convection flow with Soret and Dufour effects through a porous medium in a co-axial cylindrical duct where the outer cylinder is maintained at constant heat flux and the inner cylinder is at a constant temperature. The concentration on the cylinders is taken to be uniform. The Brinkman-Forchheimer-extended Darcy equations which take into account the boundary and inertia effects are used in the governing linear momentum equations. The effect of density variation is confined to the buoyancy term under Boussinesq approximation. The behaviour of velocity, temperature and concentration is analyzed at different axial positions. The shear stress and the rate of heat and mass transfer have also been obtained for variations in the governing parameters.

density, temperature, mixed convection, heat and mass transfer, chemical reaction, finite element method.