|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online November 5, 2004
Journal of Experimental Biology 207, 4255-4268 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01283
The relationship between wingbeat kinematics and vortex wake of a thrush nightingale


1 Department of Animal Ecology, Lund University, Ecology Building, SE-223 62
Lund, Sweden
2 Department of Aerospace and Mechanical Engineering, University of Southern
California, Los Angeles, CA 90089-1191, USA
* Author for correspondence (e-mail: m.rosen{at}usc.edu)
Accepted 14 September 2004
The wingbeat kinematics of a thrush nightingale Luscinia luscinia were measured for steady flight in a wind tunnel over a range of flight speeds (510 m s1), and the results are interpreted and discussed in the context of a detailed, previously published, wake analysis of the same bird. Neither the wingbeat frequency nor wingbeat amplitude change significantly over the investigated speed range and consequently dimensionless measures that compare timescales of flapping vs. timescales due to the mean flow vary in direct proportion to the mean flow itself, with no constant or slowly varying intervals. The only significant kinematic variations come from changes in the upstroke timing (downstroke fraction) and the upstroke wing folding (span ratio), consistent with the gradual variations, primarily in the upstroke wake, previously reported.
The relationship between measured wake geometry and wingbeat kinematics can be qualitatively explained by presumed self-induced convection and deformation of the wake between its initial formation and later measurement, and varies in a predictable way with flight speed. Although coarse details of the wake geometry accord well with the kinematic measurements, there is no simple explanation based on these observed kinematics alone that accounts for the measured asymmetries of circulation magnitude in starting and stopping vortex structures. More complex interactions between the wake and wings and/or body are implied.
Key words: wingbeat kinematics, vortex wake, thrush nightingale, Luscinia luscinia, DPVI, aerodynamics, bird flight, bird, wind tunnel
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
P. Henningsson, G. R. Spedding, and A. Hedenstrom Vortex wake and flight kinematics of a swift in cruising flight in a wind tunnel J. Exp. Biol., March 1, 2008; 211(5): 717 - 730. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. R. Spedding, A. H. Hedenstrom, J. McArthur, and M. Rosen The implications of low-speed fixed-wing aerofoil measurements on the analysis and performance of flapping bird wings J. Exp. Biol., January 15, 2008; 211(2): 215 - 223. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. C. Carruthers, A. L. R. Thomas, and G. K. Taylor Automatic aeroelastic devices in the wings of a steppe eagle Aquila nipalensis J. Exp. Biol., December 1, 2007; 210(23): 4136 - 4149. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. W. Tobalske Biomechanics of bird flight J. Exp. Biol., September 15, 2007; 210(18): 3135 - 3146. [Abstract] [Full Text] [PDF] |
||||
![]() |
M Rosen, G.R Spedding, and A Hedenstrom Wake structure and wingbeat kinematics of a house-martin Delichon urbica J R Soc Interface, August 22, 2007; 4(15): 659 - 668. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. W. Tobalske, D. R. Warrick, C. J. Clark, D. R. Powers, T. L. Hedrick, G. A. Hyder, and A. A. Biewener Three-dimensional kinematics of hummingbird flight J. Exp. Biol., July 1, 2007; 210(13): 2368 - 2382. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. M. L. Norberg and Y. Winter Wing beat kinematics of a nectar-feeding bat, Glossophaga soricina, flying at different flight speeds and Strouhal numbers J. Exp. Biol., October 1, 2006; 209(19): 3887 - 3897. [Abstract] [Full Text] [PDF] |
||||
![]() |
A Hedenstrom, M Rosen, and G.R Spedding Vortex wakes generated by robins Erithacus rubecula during free flight in a wind tunnel J R Soc Interface, April 22, 2006; 3(7): 263 - 276. [Abstract] [Full Text] [PDF] |
||||
![]() |
F.-O. Lehmann, S. P. Sane, and M. Dickinson The aerodynamic effects of wing-wing interaction in flapping insect wings J. Exp. Biol., August 15, 2005; 208(16): 3075 - 3092. [Abstract] [Full Text] [PDF] |
||||