Aidan Hickie-Bentzen, Syeda Humaira Tasnim, Shohel Mahmud
Abstract: The use of low melting point liquid metals in the thermal management of various systems has seen a recent increase in popularity with the increasing power of commercial CPUs. Natural convection in concentric annuli has also been a popular topic in the literature for decades due to the applications in nanotechnology and energy storage systems. In this study, numerical simulations are performed to investigate magnetohydrodynamic natural convection heat transfer in a horizontal concentric annulus with internal straight, Y-shapes, and T-shaped fins approximated as thin layers. A mix of transient and steady state simulations are conducted using COMSOL Multiphysics® with constant temperature boundary conditions to generate laminar natural convection profiles in the enclosure filled with a eutectic In-Ga-Sn alloy. The average Nusselt number (Nu) at the outer boundary is calculated to compare all simulation results. The Rayleigh number (Ra) is varied to investigate the stability of the flow profile over time, first without fins and then with straight fins. The three fin geometries are then compared at various Ra values to gauge their relative performance, and lastly the magnetic field is implemented at constant Ra for various Hartmann numbers (Ha). The fins are found to increase the stability of the flow profile over time, while the Y-shaped fins increase Nu by up to 318.7% compared to no fins at Ra = 104. The magnetic field forces more even heat dissipation through the enclosure, and at Ha = 20, Nu increases by a further 78.1% for the Y-shaped fins at Ra = 104.
Keywords: In-Ga-Sn alloy; low melting point liquid metal; magnetohydrodynamic natural convection; T-shaped fins; thermal management; Y-shaped fins
Date Published: September 6, 2022 DOI: 10.11159/jffhmt.2022.010
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