Impact of power law fluid and magnetic field on double diffusive mixed convection in staggered porous cavity considering Dufour and Soret effects

Abstract

This study deals the influence of power law fluid and inclined magnetic field on a porous medium in staggered cavity. The effect of Soret and Dufour parameters are also given attention. A two dimensional system of partial differential equations has been discretized by employing Galerkin finite element method. A finite element method involving the cubic polynomials (ℙ3) has been implemented to compute for velocity, temperature and concentration fields while the pressure is approximated by quadratic (ℙ2) finite element space of functions. The system of discretized equations is simplified using the adaptive Newton's method. Simulations are performed for various ranges of pertinent parameters such as power law index (between 0.6 and 1.8), Hartmann number (between 0 and 100), Lewis number (between 1 and 10), Dufour/Soret numbers (between −3 and 3), Darcy number (between 10−5 and 10−2), magnetic field inclination (between 0∘ and 90∘) and buoyancy ratio (between 0 and 10). It is inferred that the retarding effect of the rising Lorentz force is pronounced on fluid flow. The convective heat transfer is enhanced with the change of Dufour number from negative to positive. The suppression on convection at the inclination angle γ = 90∘ is much more than γ = 0∘. The increment in Dufour and Soret numbers has an improving influence on both the average Nusselt and Sherwood numbers, and thus the convective heat and mass transfer at buoyancy ratio N = 10.