Aerodynamic influence of leading-edge serrations on an airfoil in a low Reynolds number: A study of an owl wing with leading edge serrations

Abstract

It is well-known that the flapping sound of owl wings is much less than that of other birds. Fine serrations equally spaced apart is found at the leading edge of the primary feathers (remiges) of owl wings, and seems to produce the silencing effect. Paying attention to the owl's posture during capturing games, the author discusses that the effect of serrations brought changes of the aerodynamic characteristic of a wing besides damping sound. By attaching jigsaw blades with different numbers of cutting teeth imitating serrations at the leading edge of a laminar wing, the aerodynamic characteristics of an airfoil were measured and the flow field around the airfoil was also visualized. The author comes to conclusion that lift force is maintainable at larger angle of attack than the prototype wing in low Reynolds numbers.