Design and experimental validation of a bio-inspired fin microchannel heat sink with superior thermal-hydraulic features

Enhanced heat transfer structures are commonly employed in plate-fin microchannel heat sinks to improve heat transfer. However, the resultant deterioration in hydraulic performance constrains the overall performance enhancement. Therefore, the drag reduction design and optimization of these enhanced heat transfer structures are crucial for improving the thermal-hydraulic performance of heat sinks. Inspired by the excellent body streamlining of marine swordfish, capable of speeds up to 130 km/h, this paper proposes and elaborately designs a novel type of bionic fins with a variable cross-section to develop highly efficient compact heat sinks. The flow and heat transfer characteristics of bionic fin heat sinks are investigated through experimental and numerical simulations. The effects of structural parameters and transverse spacing on the comprehensive performance of bionic fin heat sinks are also studied. The results show that the small windward area of the bionic fin reduces flow velocity in the channel, which helps to reduce the pressure drop. The variable cross-section characteristics of the bionic fin induce secondary flow in the head and tail regions of the fin, thereby enhancing the heat transfer. The intensity of the secondary flow increases with the Reynolds number (Re) and the curvature of the bionic fin, further enhancing the overall performance of the heat sink. Compared to the airfoil fin heat sink, the bionic fin heat sink exhibits better comprehensive performance. The improvements in pressure drop and heat transfer of the bionic fin heat sink become more pronounced as the Re increases and the transverse spacing decreases.