Effect of Rayleigh number on Heat Transfer Characteristics of Finned Heat sink
DOI:
https://doi.org/10.38032/scse.2025.3.161Keywords:
Natural Convection, Heat Sink, Rayleigh Number, Buoyancy Force, Thermal ResistanceAbstract
In the present work, the performance of a vertical rectangular fin array based on a horizontal heat sink is analyzed for various Rayleigh number with increasing heating power by numerical analysis of steady state natural convection heat transfer. The continuity, momentum, and energy equations are solved using three-dimensional numerical simulations with FLUENT software to forecast the flow and temperature field with air as working medium. Governing equations are discretized and evaluated throughout the solid heat sink and fluid air computational domain. Fins made of aluminum with a high thermal conductivity were chosen for better heat dissipation. The enhancement of temperature differentials between the fluid domain and heat sink causes the Rayleigh number to rise with increased heating power. Using fixed fin base length, the declining character of thermal resistance, enhancement of heat transfer coefficients and Nusselt numbers were analyzed for Rayleigh numbers ranging from 4×106 to 20×106. The temperature increases across the heat sink array, reaches to maximum in the middle, and then progressively releases the heat through the fins bodies into the surrounding air. Fluid flow and thermal structure between the transverse and longitudinal fin channels as well as along the entire fin array were depicted. Two different kinds of flow patterns were identified in the fin arrays channel, and the temperature flow had a parabolic structure.
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Copyright (c) 2025 Oishi Kanta, Md Abdullah Al Mohotadi, Khandkar Aftab Hossain (Author)
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