Effect of bio-inspired sinusoidal leading-edges on wings

Observations of maneuvering humpback whales have revealed unique hydrodynamic performance hypothesized to be a result of tubercles on the leading-edge of the whales' pectoral flippers. Inspired by this biological observation, it is shown sinusoidal leading-edge wings prevent the dramatic loss of lift caused by stall and instead generate a gradual decrease in lift with as much as 25% higher lift in the poststall regime. Six different wing geometries, smooth and sinusoidal leading-edge models, swept and unswept configurations, were tested at angles of attack of −2 to 24 degrees at Reynolds numbers between 100,000 and 500,000. Oil surface flow visualization and CFD results reveal variations in flow phenomena between the smooth and sinusoidal leading-edge configurations.