Magnetohydrodynamic conjugate mixed convection, Joule Heating, and entropy generation through a ferrofluid filled T-shaped open miniature chamber with a Heat-Generating circular rod

Abstract

The present study computationally investigates magnetohydrodynamic (MHD) mixed convective fluid circulation and entropy generation in a T-shaped open chamber containing a heat-generating and conducting cylinder. Ferrofluid is circulated through the enclosure by entering at the bottom and leaving from the top of both side openings. This study utilizes the finite element scheme to unravel the leading thermal energy and Navier-Stokes equations, employing suitable auxiliary conditions. This research aims to analyze the effects of governing non-dimensional governing and geometric parameters and explore the best thermo-fluid performance inside the enclosure. The geometrical and controlling parameters are the cylinder location in the vertical direction (δ = 0.6, 0.7, 0.8), Reynolds number (31.62 ≤ Re ≤ 316.23), Grashof number (10³ ≤ Gr ≤ 10⁵), Richardson number (0.1 ≤ Ri ≤ 10), Stuart number (0 ≤ N ≤ 3.16), Hartmann number (0 ≤ Ha ≤ 17.78), and Joule heating parameter (0 ≤ J ≤ 4.57 × 10⁻⁸). The outcomes of this investigation are assessed using numerical computations of the overall entropy generation within the enclosure, average Nusselt number along the edge of the heated cylinder, mean temperature of the solid cylinder, and thermal performance criterion for six distinct cases. Furthermore, a visual depiction of the fluid circulation and thermal fields is presented. Upon thorough examination, it becomes evident that elevated Reynolds and Grashof numbers result in increased heat transport and reduced entropy production. Moreover, the optimal vertical location of the cylinder is identified at 0.6 times the chamber height. The maximum Nusselt number is achieved in Case 1 (at fixed N and Gr), where a 26.78 % improvement can be obtained by adjusting the parameter values at δ = 0.6. The inclusive discoveries of the current study grasp the noteworthy potential for apprising the design of miscellaneous thermal systems, together with solar thermal collectors, nuclear reactor cooling, electronic cooling, etc.