Numerical modelling of double-diffusive natural convection within an arc shaped enclosure filled with a porous medium

Document Type : Full Lenght Research Article

Authors

1 Faculty of Mechanical Engineering, Semnan University, Semnan, Iran

2 Faculty of Chemical Engineering, Semnan University, Semnan, Iran

Abstract

Numerical study of double-diffusive natural convective heat transfer in a curved cavity filled
with a porous medium has been carried out in the current study. Polar system has been
selected as coordinate system. As a result, all equations have been discredited in r and θ
directions. Brinkmann extended Darcy model has been utilized to express fluid flow in
porous matrix in the enclosure. Smaller and larger curved walls are supposed to be hot and
cold sources, respectively. Other two walls are insulated. The numerical solution has been
obtained based on the finite volume methodology via staggered grid system, which will be
explained in detail in its respective section. Finally, at the result section the effects of all
pertinent parameters i.e. Grashof number, Lewis number, Darcy number, and Buoyancy ratio
on the fluid motion and medium thermal behavior have been illustratively discussed. Results
reveal that an increasing in Lewis number has a negative effect on heat transfer, while it has
a positive impact on mass transfer. It is also seen that the flow intensity is increased by
decreasing Lewis number. In addition, it is observed that for the aiding flow case, average
Nu and Sh numbers decrease with increasing buoyancy ratio, while for opposing flow cases
Nu and Sh augment with decreasing buoyancy ratio.

Keywords


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