Lift performance of a cambered wing for aerodynamic performance enhancement of the flapping wing

Abstract

Flapping-Wing Micro Air Vehicles (FW-MAVs) are small hand-held flying vehicles that can maneuver in constrained space owing to its lightweight, low aspect ratio and the ability to fly in low Reynolds number environment. In this study, the aerodynamic characteristics such as time-averaged lift of camber wings with different five wind tunnel test models with 6, 9, 12, and 15 percent camber were developed and the results were compared with time-averaged lift of a flat wing in order to assess the effects of camber wing on the aerodynamic performance for flapping flight applications. The experiments were performed in an open circuit wind tunnel with of non-return airflow with a test section of (0.3 x 0.3) m and capable of speeds from 0.5 to 30 m/s. The time-averaged lift as functions of advance ratio of the flapping motions with respect to the incoming flows are measured by using a strain gauge balance and KYOWA PCD-300A sensor interface data acquisition system. It is found that camber would bring significant aerodynamic benefits when the flapping flight is in unsteady state regime, with advance ratio less than 1.0. The aerodynamic benefits of camber are found to decay exponentially with the increasing advance ratio. Cambered wing shows significantly higher lift in comparison to the flat wing.