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

Abstract

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