Numerical investigation of double-diffusive natural convection in a staggered cavity with two triangular obstacles

The main goal of this study is to investigate double-diffusive natural convection in a complex enclosure containing two equilateral triangular obstacles. The triangles and the horizontal walls are isolated, while the left and right vertical walls are considered at high and low temperatures and concentrations, respectively. The evolved transport equations are solved numerally using Galerkin finite element method. To depict the influence of pertinent physical parameters on the heat and mass transfer, the study explored a range of parameters like Rayleigh number (Ra=10(4)-10(6)), Lewis number (Le=1-10), the ratio of buoyancy (N=-5-5), and size of the inner triangle (TL). The obtained results are presented through stream functions, isotherm, and iso-concentration contours. Moreover, the average Nusselt number (Nu(avg)) and the average Sherwood number (Sh(avg)) are also computed to study the effect of considered factors on heat and mass transfer. The result indicates that, as Ra and N increase, both Nu(avg) and Sh(avg) increase, whereas they decrease when the TL ratio increases. On the other hand, when Le increases, Nu(avg) decreases, and Sh(avg) increases. Also, it finds that, when TL increases, the maximum reduction in Nu(avg) and Sh(avg) is about 15.3% and 5.1% respectively, at N=4, Le=4, and Ra=10(6).