Optimal Thermal Design of CPU Heat Sinks: Numerical Study of Pin-Fin Geometry and Nanofluids
Jogesh Roy, Shahnaz Parvin Mila, Md. Sohel Rana, Md. Tabil Ahammed
Abstract
This study numerically investigates the thermal performance of a rectangular channel CPU heat sink using five micro pin-fin geometries (triangular, circular, square, parabolic, hexagonal) and two nanofluids (AI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>0<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>-water and CuO-water). A 3D computational fluid dynamics (CFD) model was developed to analyze heat transfer characteristics under laminar-to-transient flow regimes (Reynolds number: 500–4000). The governing equations (continuity, momentum, energy) were solved using a finite volume method with a SST turbulence model. Results demonstrate that nanofluids significantly enhance the Nusselt number (Nu) compared to air, with Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>0<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>-water outperforming CuO-water. Circular pin-fins achieved the highest increase in Nu (67. 01 % at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Re}=500)$</tex>, followed by hexagonal and square fins. Increasing AlO volume fraction (1–4 %) further improved Nu by up to 4.9%. The combined use of circular pin-fins and Al2 0<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> -water nanofluid is recommended for optimal thermal management in electronics cooling.