Thermal performance of open microchannel heat sink with NACA airfoil shaped pin fins

The main purpose of this study is to numerically investigate the effect of pin-fin National Advisory Committee for Aeronautics (NACA) airfoil on the heat transfer performance of a single open microchannel heat sink with a fixed surface area and a constant wall heat flux. It was found that the helical flow within the microchannel and the converging-diverging flow near the two sides of the microchannel, caused by the periodically arranged NACA airfoil shaped pin fins with an attack angle, dominate the overall heat dissipation ability of the heat sink. The heat dissipation ability can be further improved by increasing the attack angle and Reynolds number. Of the airfoils considered, the symmetrical airfoil NACA0012 in no attack angle case presents the smallest pressure drop, but also the smallest thermal performance value, which can still achieve a Nusselt number improvement of 35.15% and a thermal performance factor (TPF) improvement of 1.38%, compared to the no-fin case. The NACA airfoil effect can be improved when asymmetric airfoils are considered. In terms of overall thermal performance, the NACA6412 would be the best choice. Its percentage increases in the Nusselt number and TPF can be further enhanced by up to 57.62% and 35.43%, respectively, compared to the no-attack-angle NACA0012 case.