Meeting Abstract
Insect wings can deform substantially during flight, exhibiting patterns of camber and twist that vary throughout a wingbeat cycle. Such deformations have profound implications on the aerodynamics and flight performance of insect flight, which, however, are difficult to quantify, especially for free flying insects. In this study, we measured the flight performance and kinematics of blue bottle flies (Calliphora vomitoria) flying steadily in a magnetic-levitated (MAGLEV) flight mill, including the flight speed, forward thrust, and wing surface deformations via combined high-speed videography and marker-less surface reconstruction. We then analyzed the underlying aerodynamics by simulating the flight kinematics using a high-fidelity, three-dimensional, computational fluid dynamics simulation, and compared the aerodynamic performance of the deformed wings and the undeformed wings. During steady flight, the flies’ wings had positive camber during downstroke and negative camber during upstroke, i.e., creating a pocket with an opening towards the stroke direction in both half strokes. The wings also exhibited continuous spanwise twists, leading to decreasing angle of attack from wing root to tip. Mean thrust generation in deformed wings increased by 26% on average compared with that of undeformed wings, as the deformation reduced the drag during downstroke and increased the thrust during upstroke, primarily due to the forward force-vectoring. Wing deformation also significantly enhanced the thrust-generation efficiency by 32%. Our results revealed the indispensable role of wing flexibility in the insect flight performance and also could have critical implications on the design of flapping-wing micro-air-vehicles.
