Author/Authors :
Ghaffarpasand Omid نويسنده head of air pollution and solid waste matter research group of environmental research institute, University of Isfahan, Iran.
Abstract :
This article describes the heat and mass transfer as well as the entropy
generation in an unsteady double-diusive natural convection with Soret and Dufour eects
in the presence of an external magnetic eld. The analysis uses a two-dimensional skewed
enclosure, where the inclined walls make a skew angle 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 nite-volume method based
on SIMPLE algorithm. The computations are carried out in the six skewed enclosures
with skew angles = 15; 30; 45; 60; 75; and 90, for a wide range of the Hartman
number, Lewis number, buoyancy ratio, and Dufour coecient, while Soret coecient is
kept constant at 0.25 in most parts of the study. Results show that the
uid
ow, 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 eect 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 coecient, while it is a decreasing
function of Hartman number.