Effect of the Reynolds Number on the Performance of a NACA0012 Wing with Leading Edge Protuberance at Low Reynolds Numbers

A study on the improvement of the NACA0012 wing performance in the low Reynolds number (Re) region of 10,000 ≤ Re ≤ 60,000 using a leading edge protuberance (LEP) was conducted. In this study, we focused on the effects of varying Re on the effectivity of the LEP. Wind tunnel tests and numerical simulations were performed to measure the wing performance and to visualize the flow structures around the airfoil. In the higher angle of attack region of α > 10^∘, LEP causes the lift to increase independently of Re. Furthermore, in the lower angle of attack region, i.e., α ≤ 10^∘, with Re ≤ 20,000, the lift coefficient also increases when using the LEP. The separation control is caused by the streamwise vortices generated by LEP which provides the momentum from the freestream flow into the separation region near the valley section, and the mechanism was basically the same at all Reynolds numbers and angle of attacks used in this study.