A computational and experimental study of flexible flapping wing aerodynamics

To gain some more understanding of the flapping wing aerodynamics and aeroelasticity associated with biological flyers and micro air vehicles (MAVs), a combined computational and experimental study of a well characterized flapping wing structure was conducted. In particular, the coupling between aerodynamics and structural dynamics plays an important role in such flyers but to date has not been adequately addressed. An aeroelasticity framework based on a co-rotational shell finite element solver with a Navier-Stokes solver is developed. Experimentally, a customized digital image correlation system measures the wing deformation, a load sensor attached to the flapping mechanism records the forces produced by the flapping motion, and a stereo digital particle image velocimetry measures the flow velocities. Computational efforts with insight into the fluid physics are reported. Relevant fluid physics are documented including the counter-rotating vortices at the leading and the trailing edge which interact with the tip vortex during the wing motion. Overall, good correlations between experiment and computation are attained. Furthermore, studies on hypothetical flexible flapping wing configurations showed that wing flexibility can be tailored to alter the aerodynamics of a flapping wing. © 2010 by the authors