Experimental and Computational Study of the Heaving and Pitching Motion of Flapping Wings

Abstract

Recent developments in micro-sized Unmanned Aerial Vehicles (UAVs) and Underwater Vehicles (UWVs) have attracted renewed research interest in flapping wing aerodynamics, especially for Micro Air Vehicles (MAV), which require to travel in confined space. In this study, force measurement, dye flow visualization and Large Eddy Simulations (LES) with Immersed Boundary (IB) method were conducted for validation purpose and investigate the aerodynamics properties of the flapping wings. In conclusion, this study has developed an experimental setup which is capable of measuring relatively small dynamic forces generated by the flapping foils at low Reynolds-numbers. Besides that, the contribution of the Leading Edge Vortex (LEV) as lift enhancement mechanism was also studied. Furthermore, the occurrence of the reverse Karman Vortex Street [1] behind the flexible flapping foil rather than in rigid flapping foil shows that the chord-wise flexibility of the flapping foil has significant contribution to the thrust.