Sökning: id:"swepub:oai:lup.lub.lu.se:d92bb662-5858-4af3-bafa-55c24d3f07e2" >
High-speed stereo D...
High-speed stereo DPIV measurement of wakes of two bat species flying freely in a wind tunnel
-
- Hedenström, Anders (författare)
- Lund University,Lunds universitet,Evolutionär ekologi,Biologiska institutionen,Naturvetenskapliga fakulteten,Evolutionary ecology,Department of Biology,Faculty of Science
-
- Muijres, Florian (författare)
- Lund University,Lunds universitet,Evolutionär ekologi,Biologiska institutionen,Naturvetenskapliga fakulteten,Evolutionary ecology,Department of Biology,Faculty of Science
-
von Busse, R. (författare)
-
visa fler...
-
Johansson, L. C. (författare)
-
Winter, Y. (författare)
-
Spedding, G. R. (författare)
-
visa färre...
-
(creator_code:org_t)
- 2009-02-28
- 2009
- Engelska.
-
Ingår i: Experiments in Fluids. - : Springer Science and Business Media LLC. - 1432-1114 .- 0723-4864. ; 46:5, s. 923-932
- Relaterad länk:
-
http://dx.doi.org/10...
-
visa fler...
-
https://lup.lub.lu.s...
-
https://doi.org/10.1...
-
visa färre...
Abstract
Ämnesord
Stäng
- Previous studies on wake flow visualization of live animals using DPIV have typically used low repetition rate lasers and 2D imaging. Repetition rates of around 10 Hz allow similar to 1 image per wingbeat in small birds and bats, and even fewer in insects. To accumulate data representing an entire wingbeat therefore requires the stitching-together of images captured from different wingbeats, and at different locations along the wing span for 3D-construction of wake topologies. A 200 Hz stereo DPIV system has recently been installed in the Lund University wind tunnel facility and the high-frame rate can be used to calculate all three velocity components in a cube, whose third dimension is constructed using the Taylor hypothesis. We studied two bat species differing in body size, Glossophaga soricina and Leptonycteris curasoa. Both species shed a tip vortex during the downstroke that was present well into the upstroke, and a vortex of opposite sign to the tip vortex was shed from the wing root. At the transition between upstroke/downstroke, a vortex loop was shed from each wing, inducing an upwash. Vorticity iso-surfaces confirmed the overall wake topology derived in a previous study. The measured dimensionless circulation, I"/Uc, which is proportional to a wing section lift coefficient, suggests that unsteady phenomena play a role in the aerodynamics of both species.
Ämnesord
- NATURVETENSKAP -- Biologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences (hsv//eng)
Publikations- och innehållstyp
- art (ämneskategori)
- ref (ämneskategori)
Hitta via bibliotek
Till lärosätets databas