Synergistic optimization of fish-shaped pin fins and non-uniform aspect ratios for enhanced hotspot thermal management

Abstract

Hotspot thermal management in high power density electronic devices presents a critical scientific challenge, as efficient heat dissipation is essential for ensuring reliable performance and longevity of such systems. This study innovatively proposes three novel microchannel cooling architectures: bio-inspired fish-shaped pin fins channels, non-uniform aspect ratio channels, and their hybrid configuration. The influence of structural parameters on flow and heat transfer characteristics was quantitatively analyzed, with comparative evaluations against conventional rectangular microchannels. Results demonstrate that the fish-shaped pin fins configuration significantly enhances average heat transfer coefficient (32.4 % enhancement) through fluid acceleration and vortex shedding effects.This configuration also achieves superior temperature uniformity (52.2 % enhancement) and hotspot temperature reduction (17.5 % decrease). Furthermore, the non-uniform aspect ratio design optimizes shear layer separation and reattachment, reducing hotspot temperatures by 16.9 % without additional flow resistance. The hybrid architecture combines the advantages of both designs, showing exceptional thermal-hydraulic performance under ultra-high heat flux (1200 W/cm²). Hotspot temperatures remain below 360 K, with a 31 % reduction in total thermal resistance (0.21 cm² K/W), a 69.1 % improvement in temperature uniformity, and a 44.6 % increase in the heat transfer coefficient. Although the pressure drop increases by 96.9 % (33.6 kPa), the overall performance surpasses conventional designs. Finally, Transformer-MLP model attains R² ≥ 0.993 across four thermal performance metrics, enabling rapid, accurate prediction and parameter optimization. This integrated numerical and machine learning approach delivers a compact, high-efficiency cooling solution with strong potential for 5G base stations and high-power lasers.