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Leading edge vortex improves lift in slow-flying bats

Muijres, Florian LU ; Johansson, Christoffer LU ; Barfield, Ryan; Wolf, Marta LU ; Spedding, Geoff and Hedenström, Anders LU (2008) In Science 319(5867). p.1250-1253
Abstract
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... (More)
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. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Science
volume
319
issue
5867
pages
1250 - 1253
publisher
The American Association for the Advancement of Science
external identifiers
  • pmid:18309085
  • wos:000253530600046
  • scopus:40049091461
ISSN
1095-9203
DOI
10.1126/science.1153019
language
English
LU publication?
yes
id
5d1caa70-ee69-45b6-a1dc-5a0a6b45612d (old id 958658)
date added to LUP
2008-01-29 13:19:20
date last changed
2017-11-19 03:38:37
@article{5d1caa70-ee69-45b6-a1dc-5a0a6b45612d,
  abstract     = {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.},
  author       = {Muijres, Florian and Johansson, Christoffer and Barfield, Ryan and Wolf, Marta and Spedding, Geoff and Hedenström, Anders},
  issn         = {1095-9203},
  language     = {eng},
  number       = {5867},
  pages        = {1250--1253},
  publisher    = {The American Association for the Advancement of Science},
  series       = {Science},
  title        = {Leading edge vortex improves lift in slow-flying bats},
  url          = {http://dx.doi.org/10.1126/science.1153019},
  volume       = {319},
  year         = {2008},
}