Experiments in Fluids

, Volume 41, Issue 2, pp 213–225 | Cite as

Time-resolved reconstruction of the full velocity field around a dynamically-scaled flapping wing

Research Article


The understanding of the physics of flapping flight has long been limited due to the obvious experimental difficulties in studying the flow field around real insects. In this study the time-dependent three-dimensional velocity field around a flapping wing was measured quantitatively for the first time. This was done using a dynamically-scaled wing moving in mineral oil in a pattern based on the kinematics obtained from real insects. The periodic flow is very reproducible, due to the relatively low Reynolds number and precise control of the wing. This repeatability was used to reconstruct the full evolving flow field around the wing from separate stereoscopic particle image velocimetry measurements for a number of spanwise planes and time steps. Typical results for two cases (an impulsive start and a simplified flapping pattern) are reported. Visualizations of the obtained data confirm the general picture of the leading-edge vortex that has been reported in recent publications, but allow a refinement of the detailed structure: rather than a single strand of vorticity, we find a stable pair of counter-rotating structures. We show that the data can also be used for quantitative studies, such as lift and drag prediction.


  1. Adrian R (1997) Dynamic ranges of velocity and spatial resolution of particle image velocimetry. Meas Sci Technol 8:1393–1398CrossRefGoogle Scholar
  2. Batchelor GK (1974) An introduction to fluid dynamics. Cambridge University Press, CambridgeGoogle Scholar
  3. Birch JM, Dickinson MH (2001) Spanwise flow and the attachment of the leading-edge vortex on insect wings. Nature 412:729–733CrossRefGoogle Scholar
  4. Birch JM, Dickinson MH (2003) The influence of wing–wake interactions on the production of aerodynamic forces in flapping flight. J Exp Biol 206:2257–2272CrossRefGoogle Scholar
  5. Birch JM, Dickson WB, Dickinson MH (2004) Force production and flow structure of the leading edge vortex on flapping wings at high and low Reynolds numbers. J Exp Biol 207(7):1063–1072CrossRefGoogle Scholar
  6. Bomphrey RJ, Lawson NJ, Harding NJ, Taylor GK, Thomas ALR (2005) The aerodynamics of Manduca sexta: digital particle image velocimetry analysis of the leading-edge vortex. J Exp Biol 208:1079–1094CrossRefGoogle Scholar
  7. Bomphrey RJ, Taylor GK, Lawson NJ, Thomas ALR (2006a) Digital particle image velocimetry measurements of the downwash behind a desert locust Schistocerca gregaria. J R Soc Interface 3(7):311–317CrossRefGoogle Scholar
  8. Bomphrey RJ, Lawson NJ, Taylor GK, Thomas ALR (2006b) Application of digital particle image velocimetry to insect aerodynamics: measurement of the leading-edge vortex and wake of a Hawkmoth. Exp Fluids 40(4):546–554CrossRefGoogle Scholar
  9. Combes SA, Daniel TL (2003) Flexural stiffness in insect wings. II. spatial distribution and dynamic wing bending. J Exp Biol 206:2989–2997CrossRefGoogle Scholar
  10. Dabiri JO (2005) On the estimation of swimming and flying forces from wake measurements. J Exp Biol 208:3519–3532CrossRefGoogle Scholar
  11. Dabiri JO (2006) Note on the induced lagrangian drift and added-mass of a vortex. J Fluid Mech 547:105–113CrossRefMathSciNetMATHGoogle Scholar
  12. Dickinson MH, Lehmann F-O, Sane SP (1999) Wing rotation and the aerodynamic basis of insect flight. Science 284(5422):1954–1960CrossRefGoogle Scholar
  13. van Doorne CWH, Westerweel J, Nieuwstadt FTM (2004) Measurement uncertainty of stereoscopiv-piv for flow with large out-of-plane motion. In: Proceedings of the EUROPIV 2 workshop held in Zaragoza, Spain, March 31–April 1, 2003, pp 213–227Google Scholar
  14. Dubief Y, Delcayre F (2000) On coherent-vortex identification in turbulence. J Turbulence 1:1–22CrossRefMathSciNetGoogle Scholar
  15. Ellington CP, Van den Berg C, Willmott AP, Thomas ALR (1996) Leading-edge vortices in insect flight. Nature 384:626–630CrossRefGoogle Scholar
  16. Fry SN, Sayaman R, Dickinson MH (2003) The aerodynamics of free-flight maneuvers in Drosophila. Science 300(5618):495–498CrossRefGoogle Scholar
  17. Fry SN, Sayaman R, Dickinson MH (2005) The aerodynamics of hovering flight in Drosophila. J Exp Biol 208(12):2303–2318CrossRefGoogle Scholar
  18. Hedenström A, Rosén M, Spedding GR (2006) Vortex wakes generated by robins erithacus rubecula during free flight in a wind tunnel. J R Soc Interface 3(7):263–276CrossRefGoogle Scholar
  19. Keane RD, Adrian RJ (1992) Theory of cross-correlation analysis of PIV analysis. Appl Sci Res 49:191–215CrossRefGoogle Scholar
  20. Meinhart CD, Wereley ST, Santiago JG (2000) A PIV algorithm for estimating time-averaged velocity fields. J Fluids Eng 122:285–289CrossRefGoogle Scholar
  21. Milano M, Gharib M (2005) Uncovering the physics of flapping flat plates with artificial evolution. J Fluid Mech 534:403–409CrossRefMATHGoogle Scholar
  22. Minotti FO, Speranza E (2005) Leading-edge vortex stability in insect wings. Phys Rev E 71:051908CrossRefGoogle Scholar
  23. Noca F, Shiels D, Jeon D (1999) A comparison of methods for evaluating time-dependent fluid dynamic forces on bodies, using only velocity fields and their derivatives. J Fluids Struct 13(5):551–578CrossRefGoogle Scholar
  24. Rayner JMV (1979) A vortex theory of animal flight .1. Vortex wake of a hovering animal. J Fluids Mech 91:697–730CrossRefMATHGoogle Scholar
  25. Sane SP, Dickinson MH (2002) The aerodynamic effects of wing rotation and a revised quasi-steady model of flapping flight. J Exp Biol 205:1087–1096Google Scholar
  26. Spedding GR, Rayner JMV, Pennycuick CJ (1984) Momentum and energy in the wake of a pigeon (Columba livia) in slow flight. J Exp Biol 111:81–102Google Scholar
  27. Spedding GR, Rosén M, Hedenström A (2003) 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 206:2313–2344CrossRefGoogle Scholar
  28. Stanislas M, Okamoto K, Kähler CJ, Westerweel J (2005) Main results of the second international PIV challenge. Exp Fluids 39:170–191CrossRefGoogle Scholar
  29. Taylor GK, Nudds RL, Thomas ALR (2003) Flying and swimming animals cruise at a strouhal number tuned for high power efficiency. Nature 425:707–711CrossRefGoogle Scholar
  30. Usherwood JR, Ellington CP (2002) The aerodynamics of revolving wings—I. model hawkmoth wings. J Exp Biol 205(11):1547–1564Google Scholar
  31. Von Ellenrieder KD, Parker K, Soria J (2003) Flow structures behind a heaving and pitching finite-span wing. J Fluid Mech 490:129–138CrossRefMATHGoogle Scholar
  32. Wang ZJ (2000) Two dimensional mechanism for insect hovering. Phys Rev Lett 85(10):2216–2219CrossRefGoogle Scholar
  33. Wang ZJ (2005) Dissecting insect flight. Annu Rev Fluid Mech 37:183–210CrossRefGoogle Scholar
  34. Westerweel J (1994) Efficient detection of spurious vectors in particle image velocimetry data. Exp Fluids 16:236–247CrossRefGoogle Scholar
  35. Wieneke B (2005) Stereo-PIV using self-calibration on particle images. Exp Fluids 39:267–280CrossRefGoogle Scholar
  36. Willert CE (1997) Stereoscopic digital particle image velocimetry for application in wind tunnel flows. Meas Sci Technol 8:1465–1479CrossRefGoogle Scholar
  37. Willmott AP, Ellington CP (1997) The mechanics of flight in the hawkmoth Manduca sexta. I. kinematics of hovering and forward flight. J Exp Biol 200:2705–2722Google Scholar
  38. Wu JC (1981) Theory for aerodynamic florce and moment in viscous flows. AIAA J 19(4):432–441CrossRefMATHGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.BioengineeringCalifornia Institute of TechnologyPasadenaUSA
  2. 2.Laboratory for Aero and HydrodynamicsDelft University of TechnologyDelftThe Netherlands

Personalised recommendations