Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-26T21:57:36.328Z Has data issue: false hasContentIssue false
  • English
  • Français

Morphology of the forced oscillatory flow past a finite-span wing at low Reynolds number

Published online by Cambridge University Press:  04 January 2007

K. PARKER ,
K. D. VON ELLENRIEDER  and
J. SORIA
K. PARKER
Affiliation:
Laboratory for Turbulence Research in Aerospace & Combustion, Mechanical Engineering, Monash University, Clayton Campus, Victoria, 3800Australia
K. D. VON ELLENRIEDER
Affiliation:
Department of Ocean Engineering, Florida Atlantic University, Dania Beach, FL 33004-3023, USA
J. SORIA
Affiliation:
Laboratory for Turbulence Research in Aerospace & Combustion, Mechanical Engineering, Monash University, Clayton Campus, Victoria, 3800Australia
Get access Rights & Permissions [Opens in a new window]

Abstract

A study of the morphology of the vortical skeleton behind a flapping NACA0030 wing with a finite aspect ratio of 3, is undertaken. The motivation for this work originates with the proposal that thrust can be efficiently produced by flapping aerofoils. The test condition corresponds to a Strouhal number of 0.35, Reynolds number, based on aerofoil chord, of 600 and an amplitude of flapping, equal to the chord length of the wing. This test condition corresponds to the optimal thrust-producing case in infinite-span flapping wings. This study investigates the effect of wing three-dimensionality on the structure of the wake-flow. This is accomplished here, by quantitatively describing the spatio-temporal variations in the velocity, vorticity and Reynolds stresses for the finite-span-wing case.

Preliminary flow visualizations suggest that the presence of wingtip vortices for the three-dimensional-wing case, create a different vortical structure to the two-dimensional-wing case. In the case of a two-dimensional-wing, the flow is characterized by the interaction of leading- and trailing-edge vorticity, resulting in the formation of a clear reverse Kármán vortex street at the selected test condition. In the case of a three-dimensional-wing, the flow exhibits a high degree of complexity and three-dimensionality, particularly in the midspan region. Using phase-averaged particle image velocimetry measurements of the forced oscillatory flow, a quantitative analysis in the plane of symmetry of the flapping aerofoil was undertaken. Using a triple decomposition of the measured velocities, the morphological characteristics of the spanwise vorticity is found to be phase correlated with the aerofoil kinematics. Reynolds stresses in the direction of oscillation are the dominant dissipative mechanism. The mean velocity profiles resemble a jet, indicative of thrust production. Pairs of strong counter-rotating vortices from the leading- and trailing-edge of the aerofoil are shed into the flow at each half-cycle. The large-scale structure of the flow is characterized by constructive merging of spanwise vorticity. The midspan region is populated by cross-sections of interconnected vortex rings.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 571 , 25 January 2007 , pp. 327 - 357
Copyright
Copyright © Cambridge University Press 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Anderson, J. M. 1996 Vortex control for efficient propulsion. PhD thesis, Massachusetts Institute of Technology and Woods Hole Oceanographic Institute.Google Scholar
Anderson, J. M., Streitlien, K., Barrett, D. S. & Triantafyllou, M. S. 1998 Oscillating foils of high propulsive efficiency. J. Fluid Mech. 360, 41–72.CrossRefGoogle Scholar
Betz, A. 1912 Ein beirtrag zur erklarung des segelfluges. Z. Flugtech. Motorluftschiff. 3, 269–272.Google Scholar
Bishop, R. E. D. & Hassan, A. Y. 1963 The lift and drag forces on a circular cylinder oscillating in a flowing fluid. Proc. R. Soc. Lond. A 277, 51–75.Google Scholar
Blondeaux, P., Fornarelli, F., Guglielmini, L., Triantafyllou, M. S. & Verzicco, R. 2005 a Numerical experiments on flapping foils mimicking fish-like locomotion. Phys. Fluids 17, 113601.CrossRefGoogle Scholar
Buchholz, J. H. J. & Smits, A. J. 2005 On the evolution of the wake structure produced by a low-aspect-ratio pitching panel. J. Fluid Mech. 546, 433–443.CrossRefGoogle Scholar
Cantwell, B. & Coles, D. 1983 An experimental study of entrainment and transport in the turbulent near wake of a circular cyclinder. J. Fluid Mech. 136, 321–351.CrossRefGoogle Scholar
Cheng, H. K. & Murillo, L. E. 1984 Lunate-tail swimming propulsion of curved lifting line in unsteady flow. Part 1. Asymptotic theory. J. Fluid Mech. 143, 327–350.CrossRefGoogle Scholar
Chong, M., Perry, A. & Cantwell, B. 1990 A general classification of three-dimensional flow fields. Phys. Fluids 2 (5), 765–777.CrossRefGoogle Scholar
DeLaurier, J. D. & Harris, J. M. 1982 Experimental study of oscillating-wing propulsion. J. Aircraft 19, 368–373.CrossRefGoogle Scholar
Dong, H., Mittal, R., Bozkurrtas, M. & Najjar, F. 2005 Wake structure and performance of finite aspect-ratio flapping foils. AIAA Paper 2005–81.CrossRefGoogle Scholar
Drucker, E. G. & Lauder, G. V. 1999 Locomotor forces on a swimming fish: three-dimensional vortex wake dynamics quantified using digital particle image velocimetry. J. Exp. Bioll. 202, 2393–2412.CrossRefGoogle ScholarPubMed
von Ellenrieder, K. D., Parker, K. & Soria, J. 2003 Flow structures behind a heaving and pitching finite-span wing. J. Fluid Mech. 490, 129–138.CrossRefGoogle Scholar
Fouras, A. & Soria, J. 1998 Accuracy of out-of-plane vorticity measurements using in-plane velocity vector field data. Exps. Fluids 25, 409–430.CrossRefGoogle Scholar
Freymuth, P. 1988 Propulsive vortical signature of plunging and pitching airfoils. AIAA J. 26, 880–883.CrossRefGoogle Scholar
Garrick, I. E. 1936 Propulsion of a flapping and oscillaing aerofoil. NACA Tech. Rep. 567.Google Scholar
Guglielmini, L. & Blondeaux, P. 2004 Propulsive efficiency of oscillating foils. Eur. J. Mech. B/Fluids 23, 255–278.CrossRefGoogle Scholar
Hama, F. R. 1962 Streaklines in a perturbed shear flow. Phys. Fluids 5 (6), 644–650.CrossRefGoogle Scholar
Hover, F. S., Haugsdal, O. & Triantafyllou, M. S. 2003 Control of angle of attack profiles in flapping foil propulsion. J. Fluids Struct. 19, 37–47.CrossRefGoogle Scholar
Hussain, A. K. M. F. 1986 Coherent structures and turbulence. J. Fluid Mech. 173, 303–356.CrossRefGoogle Scholar
Hussain, A. K. M. F. & Reynolds, W. C. 1970 The mechanics of an organized wave in turbulent shear flow. J. Fluid Mech. 41, 241–258.CrossRefGoogle Scholar
Jones, K. D., Dohring, C. M. & Platzer, M. F. 1996 Wake structures behind plunging airfoils: a comparison of numerical and experimental results. AIAA Paper 96-0078.CrossRefGoogle Scholar
Jones, K. D., Castro, B. M., Mahmoud, O., Pollard, S. J., Platzer, M. F., Neef, M. F., Gonet, K. & Hummel, D. 2002 A collaborative numerical and experimental investigation of flapping-wing propulsion in ground effect. AIAA Paper 2002-0706.CrossRefGoogle Scholar
Katz, J. & Weihz, D. 1978 Behaviour of vortex wakes from oscillating airfoils. J. Aircraft 50, 861–863.CrossRefGoogle Scholar
Katzmayr, R. 1922 Effect of periodic changes in the angle of attack on behavior of airfoils. NACA Tech. Rep. 147.Google Scholar
Knoller, R. 1909 Die gesetze des luftwiderstandes. Flug Motortechnik 3 (21), 1–7.Google Scholar
Koochesfahani, M. M. 1989 Vortical patterns in the wake of an oscillating airfoil. AIAA J. 27, 1200–1205.CrossRefGoogle Scholar
Lozano, A., Kostas, J. & Soria, J. 1998 Use of holography in particle image velocimetry measurements of a swirling flow. Exps. Fluids 26, 111–128.Google Scholar
Parker, K., von Ellenrieder, K. & Soria, J. 2002a The effects of phase angle on the vortical signatures behind a flapping airfoil of finite aspect ratio. In Proc. 10th Intl Symp. Flow Visualization (ed. Takahashi, & Ohmi, K.). Japanese Visualization Society.Google Scholar
Parker, K., von Ellenrieder, K. & Soria, J. 2002 b Flow visualization of the effect of pitch amplitude changes on the vortical signatures behind a three dimensional flapping airfoil. In Proc. SPIE, vol. 5058, Optical Technology and Image Processing for Fluids and Solids Diagnostics (ed. Shen, G. X., Cha, S. S., Chiang, F.-P. & Mercer, C. R.), pp. 331–343.Google Scholar
Parker, K., von Ellenrieder, K. & Soria, J. 2003 Strouhal number dependence of the vortex aspect ratio behind a three dimensional heaving airfoil. In Proc. 2nd Intl Conf. on Heat Transfer, Fluid Mechanics and Thermodynamics, Zambia. HEFAT (ed. Meyer, J.), Paper A121. The University of Petoria.Google Scholar
Parker, K., von Ellenrieder, K. & Soria, J. 2004 Stereoscopic PIV measurements of the flow past a circular cylinder at Reynolds number 15 000, In Proc. 15th Australasian Fluid Mech. Conf. (ed. Behnia, M., Lin, W. & McBain, G. D.), Paper AFMC00226, University of Sydney, (CD-ROM).Google Scholar
Parker, K., von Ellenrieder, K. & Soria, J. 2005 Using stereo multigrid DPIV measurements to investigate the vortical skeleton behind a finite-span flapping wing. Exps. Fluids 39, 281–298.CrossRefGoogle Scholar
Platzer, M. F. 2001 Flapping wing propulsion. Tech. Rep. Naval Postgraduate School-Monterey, CA.Google Scholar
Pope, S. B. 2000 Turbulent Flows. Cambridge University Press.CrossRefGoogle Scholar
Reynolds, W. C. & Hussain, A. K. 1972 The mechanics of an organized wave in turbulent shear flow. Part 1. Theoretical models and comparisons with experiments. J. Fluid Mech. 54, 263–290.CrossRefGoogle Scholar
Soria, J. 1996 An investigation of the near wake of a circular cylinder using a video-based digital cross-correlation particle image velocimetry technique. Expl Thermal Fluid Sci. 12, 221–233.CrossRefGoogle Scholar
Soria, J. 1998 Multigrid approach to cross-correlation digital PIV and HPIV analysis. In Proc. 13th Australasian Fluid Mech. Conf. (ed. Soria, J.), Paper AFMC0010. Monash University (CD-ROM).Google Scholar
Tennekes, H. & Lumley, J. 1972 A First Course in Turbulence. MIT Press.CrossRefGoogle Scholar
Triantafyllou, M. S., Triantafyllou, G. S. & Yue, D. K. P. 2000 Hydrodynamics of fishlike swimming. Annu. Rev. Fluid Mech. 32, 33–53.CrossRefGoogle Scholar
Triantafyllou, M. S., Techert, A. H. & Hover, F. S. 2004 Review of experimental work in biomimetics foils. J. Ocean Engng 29, 585–594.CrossRefGoogle Scholar
Tuncer, I. A., Walz, R. & Platzer, M. F. 1998 A computational study of the dynamic stall of a flapping airfoil. Tech. Rep. 98-2519. Naval Postgraduate School, Monterey, CA.CrossRefGoogle Scholar