Synergetic Flow Control and Wing Flexibility Effect in a Tandem Wing Insect Flight

The behavior of insect flight is of significant interest for designing human-engineered flapping-wing-based micro air vehicles, In this talk, the wing kinematics, vortex-wing interactions, and active/passive natures of wing pitching of dragonflies are presented. The flow around the flapping wings, wing deformation and the pitching mechanisms of the wings on the aerodynamics of dragonflies were investigated. The flow fields and pitching angle variations of the naturally actuated wing of the dragonfly were compared with that of the same wing artificially actuated only by flapping motion. We found that the trailing edge vortex dynamics and the wake were affected by the wing shape only for the in-vivo experiment with muscle induced pitching. These results suggest the pitching motion of the wings can be active and passive depending on flight models of insect flight. The spanwise variation in vortex-wing interactions can be exploited in the design of artificial wings to achieve greater agility and higher efficiency.