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Comparative aerodynamic performance of flapping flight in two bat species using time-resolved wake visualization.

Muijres, Florian LU ; Johansson, Christoffer LU ; Winter, York and Hedenström, Anders LU (2011) In Journal of the Royal Society, Interface 8. p.1418-1428
Abstract
Bats are unique among extant actively flying animals in having very flexible wings, controlled by multi-jointed fingers. This gives the potential for fine-tuned active control to optimize aerodynamic performance throughout the wingbeat and thus a more efficient flight. But how bat wing performance scales with size, morphology and ecology is not yet known. Here, we present time-resolved fluid wake data of two species of bats flying freely across a range of flight speeds using stereoscopic digital particle image velocimetry in a wind tunnel. From these data, we construct an average wake for each bat species and speed combination, which is used to estimate the flight forces throughout the wingbeat and resulting flight performance properties... (More)
Bats are unique among extant actively flying animals in having very flexible wings, controlled by multi-jointed fingers. This gives the potential for fine-tuned active control to optimize aerodynamic performance throughout the wingbeat and thus a more efficient flight. But how bat wing performance scales with size, morphology and ecology is not yet known. Here, we present time-resolved fluid wake data of two species of bats flying freely across a range of flight speeds using stereoscopic digital particle image velocimetry in a wind tunnel. From these data, we construct an average wake for each bat species and speed combination, which is used to estimate the flight forces throughout the wingbeat and resulting flight performance properties such as lift-to-drag ratio (L/D). The results show that the wake dynamics and flight performance of both bat species are similar, as was expected since both species operate at similar Reynolds numbers (Re) and Strouhal numbers (St). However, maximum L/D is achieved at a significant higher flight speed for the larger, highly mobile and migratory bat species than for the smaller non-migratory species. Although the flight performance of these bats may depend on a range of morphological and ecological factors, the differences in optimal flight speeds between the species could at least partly be explained by differences in their movement ecology. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
aerodynamics, bats, flight, particle image velocimetry, wind tunnel
in
Journal of the Royal Society, Interface
volume
8
pages
1418 - 1428
publisher
Royal Society
external identifiers
  • WOS:000294208100006
  • Scopus:80052235189
DOI
10.1098/rsif.2011.0015
language
English
LU publication?
yes
id
2573d12b-53c5-41cf-9fe9-b1539947ea14 (old id 1886285)
date added to LUP
2011-04-05 13:58:33
date last changed
2016-10-13 04:47:00
@misc{2573d12b-53c5-41cf-9fe9-b1539947ea14,
  abstract     = {Bats are unique among extant actively flying animals in having very flexible wings, controlled by multi-jointed fingers. This gives the potential for fine-tuned active control to optimize aerodynamic performance throughout the wingbeat and thus a more efficient flight. But how bat wing performance scales with size, morphology and ecology is not yet known. Here, we present time-resolved fluid wake data of two species of bats flying freely across a range of flight speeds using stereoscopic digital particle image velocimetry in a wind tunnel. From these data, we construct an average wake for each bat species and speed combination, which is used to estimate the flight forces throughout the wingbeat and resulting flight performance properties such as lift-to-drag ratio (L/D). The results show that the wake dynamics and flight performance of both bat species are similar, as was expected since both species operate at similar Reynolds numbers (Re) and Strouhal numbers (St). However, maximum L/D is achieved at a significant higher flight speed for the larger, highly mobile and migratory bat species than for the smaller non-migratory species. Although the flight performance of these bats may depend on a range of morphological and ecological factors, the differences in optimal flight speeds between the species could at least partly be explained by differences in their movement ecology.},
  author       = {Muijres, Florian and Johansson, Christoffer and Winter, York and Hedenström, Anders},
  keyword      = {aerodynamics,bats,flight,particle image velocimetry,wind tunnel},
  language     = {eng},
  pages        = {1418--1428},
  publisher    = {ARRAY(0xa8aefe0)},
  series       = {Journal of the Royal Society, Interface},
  title        = {Comparative aerodynamic performance of flapping flight in two bat species using time-resolved wake visualization.},
  url          = {http://dx.doi.org/10.1098/rsif.2011.0015},
  volume       = {8},
  year         = {2011},
}