Numerical Investigation of Hydrothermal Performance of Twisted Elliptical Pin‐Fin Heat Sinks

ABSTRACT The present study numerically investigates the hydrothermal performance of twisted elliptical pin‐fin (EPF) heat sinks with varying perforation levels. A total of 148 three‐dimensional computational fluid dynamics (CFD) simulation cases were executed, using the RANS‐based turbulence model over a Reynolds number range of 8547–21,367, with cylindrical pin fins used as the baseline for comparison. Results show that increasing the twist angle enhances heat transfer due to twisting‐induced swirling flows and perforations, which increase cross‐flow, surface area, and vortex formation. At Re = 21,367, the Nusselt number achieved a maximum enhancement of 57% for the T120 configuration compared to the cylindrical baseline. However, this improvement was accompanied by a 41% increase in pressure drop. Moderate twist angles provided a better thermal‐hydraulic trade‐off. Configurations with twist angles below 60° achieved significant heat transfer enhancement while reducing pressure losses, with T30 showing a 27% pressure drop reduction and T0 achieving up to a 40% reduction compared to the baseline. The EPF‐T30‐P3 configuration obtained the maximum hydrothermal performance factor (HTPF) value of 2.06. These findings demonstrate that moderately twisted and perforated elliptical pin fins offer an effective balance between heat transfer enhancement and flow resistance, providing practical guidance for the design of compact, high‐efficiency air‐cooled heat sinks.