Leading-Edge Vortex lifts swifts

J. J. Videler, E. J. Stamhuis, G. D. E. Povel

OnderzoeksoutputAcademicpeer review

123 Citaten (Scopus)


The current understanding of how birds fly must be revised, because birds use their hand-wings in an unconventional way to generate lift and drag. Physical models of a common swift wing in gliding posture with a 60degrees sweep of the sharp hand-wing leading edge were tested in a water tunnel. Interactions with the flow were measured quantitatively with digital particle image velocimetry at Reynolds numbers realistic for the gliding flight of a swift between 3750 and 37,500. The results show that gliding swifts can generate stable leading-edge vortices at small (5degrees to 10degrees) angles of attack. We suggest that the flow around the arm-wings of most birds can remain conventionally attached, whereas the swept-back hand-wings generate lift with leading-edge vortices.

Originele taal-2English
Pagina's (van-tot)1960-1962
Aantal pagina's3
Nummer van het tijdschrift5703
StatusPublished - 10-dec-2004

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