Unsteady double-diffusive natural convection with Soret and Dufour effects inside a two-sided lid-driven skewed enclosure in the presence of applied magnetic field

This article describes the heat and mass transfer as well as the entropy generation in an unsteady double-diffusive natural convection with Soret and Dufour effects in the presence of an external magnetic field. The analysis uses a two-dimensional skewed enclosure, where the inclined walls make a skew angle λ with x-axis. The governing equations in the physical domain are transformed into an orthogonal computational domain by co-ordinate transformations, and then are solved using a finite-volume method based on SIMPLE algorithm. The computations are carried out in the six skewed enclosures with skew angles A = 15°, 30°, 45°, 60°, 75°, and 90°, for a wide range of the Hartman number, Lewis number, buoyancy ratio, and Dufour coefficient, while Soret coefficient is kept constant at 0.25 in most parts of the study. Results show that the fluid flow, heat and mass transfer, as well as the entropy generation are sensitive to some extent to the skew angle variation. Meanwhile, the Lewis number and buoyancy ratio have aiding and opposing actions, respectively, on suppression effect of Lorentz force against convective heat and mass transfer. It is also shown that the average entropy generation is an increasing function of Lewis number, buoyancy ratio, and Dufour coefficient, while it is a decreasing function of Hartman number.