Aerodynamic Characteristics of Elastic Wings Morphed and Vibrated in Uniform Flows and Separated Flows Around Them

摘要

In this study, experimental investigation is performed into modification to aerodynamic characteristics by distortion and vibration of planar wings with various Young's modulus as well as flow fields around them. Motions of the wings are captured with a high-speed camera. Flows around them are evaluated with phase locked PIV technique. As a result, bending vibration of the wings is observed almost all over the angles of attack while twisting is observed around the angles giving maximum lift force. The twisting vibration causes larger aerodynamic forces and delay in the stall. It is found that amplitude of the twisting determines magnitude of variations in aerodynamic forces. Flow field measurement shows the twisting vibration generates periodic vortices shedding from the leading and trailing edges. They reduce the separation bubble on the wing, in particular, around the middle span in spite of localization of the twisting in the vicinity of the wing tip.