Thermal performance of cold plates with novel pin-fins designed using Bézier curves

Abstract

This report explores the use of Bézier curves to form novel pin-fin shapes. Bézier curves are promising in their use for shape optimization since they are flexible enough to take all possible shapes in the design space. The pin-fin geometry is altered by adjusting the location of the control points. For this study, the Bézier curves used each had 5 control points. The study was conducted for single-phase liquid cooling in the laminar regime (200≤ Re≤1000). Numerical investigations were carried out using aluminium alloy material (AlSi10Mg) as the cold plate material with deionized water as the coolant. In total, 7 different pin-fin geometries were explored. Overall, the novel wing-shaped pin-fins had the best thermal performance at Reynolds number (Re) of 1000. The velocity contours of the various pin-fin geometries confirmed that the pin-fins disrupt steady flow and accelerate the flow due to the decrease in cross-sectional area. For the pin-fin configurations simulated, the Nusselt number (Nu) increases while the friction factor generally decreases with higher Re. It is also observed that at lower Re, a higher Nu plays a significant role in achieving better thermal performance while at higher Re, a lower friction factor is more crucial. To validate the numerical results and further demonstrate the potential applications of such pin-fin shapes, experimental investigations were also conducted for circle and ellipse shaped pin-fins, which were designed using Bézier curves and subsequently printed through additive manufacturing. This study highlights the flexibility of Bézier curves in producing different pin-fin geometries.