Eur. Phys. J. Plus (2021) 136: 814
https://doi.org/10.1140/epjp/s13360-021-01812-2

Regular Article

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

¹ Department of Mechanical Engineering, University of Al-Qadisiyah, Ad-Diwaniyah, Iraq
² Mechanical Engineering Department, Engineering College, University of Basrah, Basrah, Iraq
³ Department of Mechanical and Maintenance Engineering, School of Applied Technical Sciences, German Jordanian University, 11180, Amman, Jordan
⁴ Department of Power Engineering, Jadavpur University, 700106, Salt Lake, Kolkata, India

^a Khaled.alfarhany@qu.edu.iq

Received: 18 June 2021
Accepted: 29 July 2021
Published online: 6 August 2021

Abstract

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 = 10⁴–10⁶), 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 = 10⁶.