Flow Separation Control on a NACA-4415 Airfoil at Low Reynolds Number

An experimental study using 3C-PIV was carried out for investigating the effect of adapting a passive flow control device similar to that found on the humpback whale flippers (tubercles) to the leading edge of a NACA-4415 airfoil at a Reynolds number of 120,000. The evolution of the mean velocity field on the NACA-4415 airfoil and with leading-edge tubercles are measured using stereo-particle image velocimetry at an angle of attack of 18°. The leading-edge tubercles exhibited attached flow up to 50% of the airfoil and reduced the height of the separated region over modified airfoil as compared to the baseline. This results in an improved aerodynamics performance by the modified airfoil.