Experimental study on the wing-wake interaction of a flapping wing Micro Aerial Vehicle

This work presents an experimental study of the aerodynamics of different types of wings during the clap-and-peel mechanism on a hovering flapping wing Micro Aerial Vehicle (MAV) platform. A comprehensive analysis of the phenomenon through force measurement, motion capture and flow measurement using Particle Image Velocimetry in a fixed position was performed. The flow field around the two types of wings with identical dimensions but different deformation characteristics is compared to understand the role of their flexibility in enhancing the benefits of clap-and-peel effect. The two wings have different configurations of carbon fiber rod stiffeners. Varying degrees of flexibility along the camber were observed in the two wings. Insights were obtained on the correlation between the chordwise camber of wings and their influence on force generation and energy efficiency of the flapping wing MAV. The relative strength and location of the leading edge vortices were compared. One of the wings exhibited higher average lift force by 32% and higher average power efficiency by 18% than the other. For Particle Image Velocimetry, Rhodamine-B fluorescent particles were used to seed the flow, over the conventional fog and oil droplets. This mitigated the optical obstruction due to reflection of the wing through the use of optical filters on camera lens.