Leading-edge vortex improves lift in slow-flying bats.


Journal Article

Staying aloft when hovering and flying slowly is demanding. According to quasi-steady-state aerodynamic theory, slow-flying vertebrates should not be able to generate enough lift to remain aloft. Therefore, unsteady aerodynamic mechanisms to enhance lift production have been proposed. Using digital particle image velocimetry, we showed that a small nectar-feeding bat is able to increase lift by as much as 40% using attached leading-edge vortices (LEVs) during slow forward flight, resulting in a maximum lift coefficient of 4.8. The airflow passing over the LEV reattaches behind the LEV smoothly to the wing, despite the exceptionally large local angles of attack and wing camber. Our results show that the use of unsteady aerodynamic mechanisms in flapping flight is not limited to insects but is also used by larger and heavier animals.

Full Text

Cited Authors

  • Muijres, FT; Johansson, LC; Barfield, R; Wolf, M; Spedding, GR; Hedenström, A

Published Date

  • February 2008

Published In

Volume / Issue

  • 319 / 5867

Start / End Page

  • 1250 - 1253

PubMed ID

  • 18309085

Pubmed Central ID

  • 18309085

Electronic International Standard Serial Number (EISSN)

  • 1095-9203

International Standard Serial Number (ISSN)

  • 0036-8075

Digital Object Identifier (DOI)

  • 10.1126/science.1153019


  • eng