Abstract
This paper presents an analytical and numerical study of natural convection in a two-dimensional square cavity filled with a binary gas due to combined temperature and concentration gradients. The transport equations are solved numerically using finite-difference techniques. Excellent comparisons have been obtained with benchmark solutions and other results available in the literature. The analysis indicates that the velocities at the vertical walls are inversely proportional to the concentration parameter Γ. For Γ » 1, the local and average Nusselt and Sherwood numbers at the vertical surfaces are independent of Γ. The analysis also reveals that the Nusselt numbers are strongly dependent on Γ for Γ < 1 as well as on Pr/Sc for N = 1. A sensitivity study indicates that the heat and mass transport across the cavity increases with ∣1 — N∣, where N is the stability number. The direction of circulation undergoes a reversal at N = 1.