|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
The Wake of a Kestrel (Falco Tinnunculus) in Flapping Flight
1 Department of Zoology, University of Bristol, Woodland Road, Bristol BS8 1UG; Department of Aerospace Engineering, University of Southern California, University Park, Los Angeles, CA 90089-0192, USA.
The structure of the wake behind a kestrel in medium-speed flight down a 36 m length of corridor was analysed qualitatively and quantitatively by stereophotogrammetry of multiple flash photographs of the motion of small soap-covered helium bubbles. The wake consists of a pair of continuous, undulating trailing vortices. The upstroke is therefore aerodynamically active and the circulation appears to remain constant along the wing whose geometry is altered during the course of the wingstroke. It is argued that the flight kinematics, and so the wake structure, of the kestrel may be typical of flapping flight at medium speeds and a flight model based on this wake geometry is presented. Rough estimates of the rate of momentum generated in the wake balance the weight almost exactly and a direct estimate of the induced power requirement from the wake measurements is obtained. The significance of these results for the various alternative aerodynamic descriptions and energetic predictions of models of flapping animal flight is briefly assessed
Key words: flight, wake, kestrel
Accepted on August 19, 1986
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]
|
|
|
|
|
|
B. W. Tobalske Biomechanics of bird flight J. Exp. Biol., September 15, 2007; 210(18): 3135 - 3146. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Hedenstrom, L. C. Johansson, M. Wolf, R. von Busse, Y. Winter, and G. R. Spedding Bat Flight Generates Complex Aerodynamic Tracks Science, May 11, 2007; 316(5826): 894 - 897. [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]
|
|
|
|
|
|
E. J. Stamhuis and S. Nauwelaerts Propulsive force calculations in swimming frogs II. Application of a vortex ring model to DPIV data J. Exp. Biol., April 15, 2005; 208(8): 1445 - 1451. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. Usherwood, T. L. Hedrick, C. P. McGowan, and A. A. Biewener Dynamic pressure maps for wings and tails of pigeons in slow, flapping flight, and their energetic implications J. Exp. Biol., January 15, 2005; 208(2): 355 - 369. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Rosen, G. R. Spedding, and A. Hedenstrom The relationship between wingbeat kinematics and vortex wake of a thrush nightingale J. Exp. Biol., November 15, 2004; 207(24): 4255 - 4268. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Hedrick, J. R. Usherwood, and A. A. Biewener Wing inertia and whole-body acceleration: an analysis of instantaneous aerodynamic force production in cockatiels (Nymphicus hollandicus) flying across a range of speeds J. Exp. Biol., April 15, 2004; 207(10): 1689 - 1702. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Andersson and J. Wallander Kin selection and reciprocity in flight formation? Behav. Ecol., January 1, 2004; 15(1): 158 - 162. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. Usherwood, T. L. Hedrick, and A. A. Biewener The aerodynamics of avian take-off from direct pressure measurements in Canada geese (Branta canadensis) J. Exp. Biol., November 15, 2003; 206(22): 4051 - 4056. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. R. Spedding, M. Rosen, and A. Hedenstrom A family of vortex wakes generated by a thrush nightingale in free flight in a wind tunnel over its entire natural range of flight speeds J. Exp. Biol., July 15, 2003; 206(14): 2313 - 2344. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Hedrick, B. W. Tobalske, and A. A. Biewener How cockatiels (Nymphicus hollandicus) modulate pectoralis power output across flight speeds J. Exp. Biol., April 15, 2003; 206(8): 1363 - 1378. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Hedrick, B. W. Tobalske, and A. A. Biewener Estimates of circulation and gait change based on a three-dimensional kinematic analysis of flight in cockatiels (Nymphicus hollandicus) and ringed turtle-doves (Streptopelia risoria) J. Exp. Biol., May 15, 2002; 205(10): 1389 - 1409. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. G. Drucker and G. V. Lauder Experimental Hydrodynamics of Fish Locomotion: Functional Insights from Wake Visualization Integr. Comp. Biol., April 1, 2002; 42(2): 243 - 257. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. WATTS, E. J. MITCHELL, and S. M. SWARTZ A COMPUTATIONAL MODEL FOR ESTIMATING THE MECHANICS OF HORIZONTAL FLAPPING FLIGHT IN BATS: MODEL DESCRIPTION AND VALIDATION J. Exp. Biol., March 10, 2002; 204(16): 2873 - 2898. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Brackenbury Kinematics and hydrodynamics of an invertebrate undulatory swimmer: the damsel-fly larva J. Exp. Biol., March 1, 2002; 205(5): 627 - 639. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. K. Bartol, R. Mann, and M. R. Patterson Aerobic respiratory costs of swimming in the negatively buoyant brief squid Lolliguncula brevis J. Exp. Biol., January 11, 2001; 204(21): 3639 - 3653. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. J. Park, M. Rosen, and A. Hedenstrom Flight kinematics of the barn swallow (Hirundo rustica) over a wide range of speeds in a wind tunnel J. Exp. Biol., January 8, 2001; 204(15): 2741 - 2750. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Brackenbury The Vortex Wake of the Free-swimming Larva and Pupa of CULEX PIPIENS (Diptera) J. Exp. Biol., January 6, 2001; 204(11): 1855 - 1867. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Anderson, W. McGillis, and M. Grosenbaugh The boundary layer of swimming fish J. Exp. Biol., January 1, 2001; 204(1): 81 - 102. [Abstract] [PDF]
|
|
|
|
|
|
M. H. Dickinson, C. T. Farley, R. J. Full, M. A. Koehl, R. Kram, and S. Lehman How Animals Move: An Integrative View Science, April 7, 2000; 288(5463): 100 - 106. [Abstract] [Full Text]
|
|
|
|
|
|
C. Pennycuick, A Hedenstrom, and M Rosen Horizontal flight of a swallow (Hirundo rustica) observed in a wind tunnel, with a new method for directly measuring mechanical power J. Exp. Biol., January 6, 2000; 203(11): 1755 - 1765. [Abstract] [PDF]
|
|
|
|
|
|
U. Muller, E. Stamhuis, and J. Videler Hydrodynamics of unsteady fish swimming and the effects of body size: comparing the flow fields of fish larvae and adults J. Exp. Biol., January 1, 2000; 203(2): 193 - 206. [Abstract] [PDF]
|
|
|
|
|
|
J. Rayner Estimating power curves of flying vertebrates J. Exp. Biol., January 12, 1999; 202(23): 3449 - 3461. [Abstract] [PDF]
|
|
|
|
|
|
E. Drucker and G. Lauder Locomotor forces on a swimming fish: three-dimensional vortex wake dynamics quantified using digital particle image velocimetry J. Exp. Biol., January 9, 1999; 202(18): 2393 - 2412. [Abstract] [PDF]
|
|
|
|
|
|
B. Tobalske, W. Peacock, and K. Dial Kinematics of flap-bounding flight in the zebra finch over a wide range of speeds J. Exp. Biol., January 7, 1999; 202(13): 1725 - 1739. [Abstract] [PDF]
|
|
