Natural convection heat transfer of a hybrid nanofluid in a permeable quadrantal enclosure with heat generation

Abstract

This study investigates the steady laminar natural convection phenomenon within a quadrantal enclosure occupied by a fluid-saturated porous medium. The enclosure undergoes internal heat generation and magnetohydrodynamic buoyancy-driven thermal energy transfer. The governing equations were nondimensionalized and resolved utilizing the FEM. The research examined the impacts of heat generation and the porous medium presence on streamlines, isotherms, and heat transfer rate from the enclosure walls. The results were obtained for the following parameter ranges: 103≤Ra≤106, 0≤Ha≤100, 0≤ϕ≤0.05. The results demonstrate the average Nusselt number depends on ϕ, exhibiting an increase with rising ϕ. Investigations revealed the Nusselt number on the heated bottom wall substantially increases with both the Rayleigh number (Ra = 105 and 106) and volume fraction ϕ = 0.01 and 0.05, with augmentations up to 9.4536 and 10.852. Additionally, complex interplay was found between the heat generation parameter λ = -5, when ϕ = 0.01, Ra = 106Nu¯ rose to 11.026 and when λ=5, yet for ϕ = 0.05, Nu¯ steeply decreased to 4.0464. The outcomes of this research could potentially improve the efficiency of heat exchangers, solar collectors, and other analogous devices reliant on natural convection heat transfer.