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Published August 2006 | metadata_only
Journal Article

Time-resolved reconstruction of the full velocity field around a dynamically-scaled flapping wing


The understanding of the physics of flapping flight has long been limited due to the obvious experimental difficulties in studying the flow field around real insects. In this study the time-dependent three-dimensional velocity field around a flapping wing was measured quantitatively for the first time. This was done using a dynamically-scaled wing moving in mineral oil in a pattern based on the kinematics obtained from real insects. The periodic flow is very reproducible, due to the relatively low Reynolds number and precise control of the wing. This repeatability was used to reconstruct the full evolving flow field around the wing from separate stereoscopic particle image velocimetry measurements for a number of spanwise planes and time steps. Typical results for two cases (an impulsive start and a simplified flapping pattern) are reported. Visualizations of the obtained data confirm the general picture of the leading-edge vortex that has been reported in recent publications, but allow a refinement of the detailed structure: rather than a single strand of vorticity, we find a stable pair of counter-rotating structures. We show that the data can also be used for quantitative studies, such as lift and drag prediction.

Additional Information

© 2006 Springer-Verlag. Received: 25 November 2005; Revised: 25 May 2006; Accepted: 27 May 2006; Published online: 6 July 2006. Support from The Netherlands Organization for Scientific Research (NWO) in the form of a 'Talent' Fellowship is gratefully acknowledged (CP). Additional support was provided by a grant from the National Science Foundation, the Packard Foundation and the Office of Naval Research (MHD).

Additional details

August 19, 2023
August 19, 2023