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Flow structure from an oscillating cylinder Part 1. Mechanisms of phase shift and recovery in the near wake

Published online by Cambridge University Press:  21 April 2006

A. Ongoren  and
D. Rockwell
A. Ongoren
Affiliation:
Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA 18015, USA
D. Rockwell
Affiliation:
Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA 18015, USA
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Abstract

Cylinders of various cross-section were subjected to controlled oscillations in a direction transverse to the incident flow. Excitation was at frequency fe, relative to the formation frequency f*0 of large-scale vortices from the corresponding stationary cylinder, and at Reynolds numbers in the range 584 [les ] Re [les ] 1300. Modifications of the near wake were characterized by visualization of the instantaneous flow structure in conjunction with body displacement-flow velocity correlations.

At fe/f*0 = ½, corresponding to subharmonic excitation, as well as at fe/f*0 = 1, the near wake structure is phase-locked (synchronized) to the cylinder motion. However, the synchronization mechanism is distinctly different in these two regimes. Near or at fe/f*0 = 1, the phase of the shed vortex with respect to the cylinder displacement switches by approximately π. Characteristics of this phase switch are related to cylinder geometry. It does not occur if the cylinder has significant afterbody.

Over a wide range of fe/f*0, the perturbed near wake rapidly recovers to a largescale antisymmetrical mode similar in form to the well-known Kármán vortex street. The mechanisms of small-scale (fe) vortex interaction leading to recovery of the large-scale (f0) vortices are highly ordered and repeatable, though distinctly different, for superharmonic excitation (fe/f*0 = n = 2, 3, 4) and non-harmonic excitation (non-integer values of fe/f*0).

The frequency f0 of the recovered vortex street downstream of the body shows substantial departure from the shedding frequency f*0 from the corresponding stationary body. It locks-on to resonant modes corresponding to f0/fe = 1/n. This wake response involves strictly hydrodynamic phenomena. It shows, however, a resonant behaviour analogous to that of coupled flow-acoustic systems where the shear layer is convectively unstable

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 191 , June 1988 , pp. 197 - 223
Copyright
© 1988 Cambridge University Press

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References

Angrilli, F., DiSilvio, G., Zanardo, D. 1974 Hydroelasticity study of a circular cylinder in a waterstreak. In Flow-Induced Structural Vibrations (ed. E. Naudascher), pp. 504–512. Springer.
Bearman, P. W. 1984 Vortex shedding from oscillating bluff bodies. Ann. Rev. Fluid Mech. 16, 195–222.Google Scholar
Bearman, P. W. & Currie, I. G. 1979 Pressure fluctuation measurements on an oscillating circular cylinder. J. Fluid Mech. 91, 661–677.Google Scholar
Bearman, P. W. & Graham, J. M. R. 1980 Vortex shedding from bluff bodies in oscillatory flow: A report on Euromech 119. J. Fluid Mech. 99, 225–245.Google Scholar
Bearman, P. W. & Obasaju, E. D. 1982 An experimental study of pressure fluctuations on fixed and oscillating square-section cylinders. J. Fluid Mech. 119, 297–321.Google Scholar
Berger, E. & Wille, R. 1972 Periodic flow phenomena. Ann. Rev. Fluid Mech. 24, 313–340.Google Scholar
Bishop, R. E. D. & Hassan, A. Y. 1964 The lift and drag forces on a circular cylinder oscillating in a flowing fluid. Proc. R. Soc. Lond. A 227, 51–75.Google Scholar
Brown, G. L. & Roshko, A. 1974 On density effects and large-scale structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.Google Scholar
Den Hartog, J. P. 1934 The vibration problems of engineering. In Proc. Fourth Intl Congr. on Applied Mechanics, Cambridge, England, pp. 36–53.
Dimotakis, P. E. & Brown, G. L. 1976 The mixing layer at high Reynolds numbers: large-scale dynamics and entrainment. J. Fluid Mech. 78, 535–560.Google Scholar
Feng, C. C. 1968 Measurement of vortex-induced effects in flow past stationary and oscillating circular and D-section cylinders. M.Sc. thesis, University of British Columbia, Vancouver, Canada.
Ferguson, M. & Parkinson, G. V. 1967 Surface and wake flow phenomena of the vortex-excited oscillation of the circular cylinder. Trans. ASME B: J. Engng for Industry 89, 831–838.Google Scholar
Gerrard, J. H. 1978 The wakes of cylindrical bluff bodies at low Reynolds number. Phil. Trans. R. Soc. Lond. A 288, 351–382.Google Scholar
Griffin, O. M. 1971 The unsteady wake of an oscillating cylinder at low Reynolds number. Trans. ASME E: J. Appl. Mech. 38, 729–738.Google Scholar
Griffin, O. M. 1973 Instability in the vortex street wakes of vibrating bluff bodies. Trans. ASME I: J. Fluids Engng 95, 569–581.Google Scholar
Griffin, O. M. & Vortex, C. W. 1972 The vortex street in the wake of a vibrating cylinder. J. Fluid Mech. 51, 31–48.Google Scholar
Ho, C. M. & Huang, L. S. 1982 Subharmonic and vortex merging in mixing layers. J. Fluid Mech. 119, 443–473.Google Scholar
Ho, C. M. & Huerre, P. 1984 Perturbed free-shear layers. Ann. Rev. Fluid Mech. 16, 365–424.Google Scholar
Ho, C. M. & Nossier, N. S. 1981 Dynamics of an impinging jet. Part I. The feedback phenomenon. J. Fluid Mech. 105, 119–142.Google Scholar
Huerre, P. & Monkewitz, P. A. 1985 Absolute and convective instabilities in free-shear layers. J. Fluid Mech. 59, 151–168.Google Scholar
Kibens, V. 1980 Interaction of jet flow field instabilities with flow system resonances. Presented at AIAA Aeroacoustics Meeting, 5–7 June, Hartford, Connecticut.
Koch, W. 1984 Local instability characteristics and frequency determination of self-excited wake flows. J. Sound Vib. 99, 53–83.Google Scholar
Koopmann, G. H. 1967a The vortex wakes of vibrating cylinders at low Reynolds numbers. J. Fluid Mech. 28, 501–512.Google Scholar
Koopmann, G. H. 1967b On the wind-induced vibrations of circular cylinders. M.Sc. thesis, Catholic University of America, Washington, DC.
Laufer, J. & Monkewitz, P. A. 1980 On the turbulent jet flow in a new perspective. AIAA Paper 80–0962.
Mair, W. A. & Maull, D. J. 1971 Bluff bodies in vortex shedding — A report on Euromech 17. J. Fluid Mech. 45, 209–224.Google Scholar
Meier-Windhorst, A. 1939 Flatterschwingungen von Zylindern im gleichmässigen Flüssigkeitsström. Mitteilungen des Hydraulischen Instituts der Technichen Hochschule, Munchen, Heft 9, pp. 3–39.
Michalke, A. 1965 On spatially growing disturbances in an inviscid shear layer. J. Fluid Mech. 23, 521–544.Google Scholar
Michalke, A. 1984 Survey on jet instability theory. Prog. Aerospace Sci. 21, 159–199.Google Scholar
Miksad, R. W. 1972 Experiments on the nonlinear stages of shear layer transition. J. Fluid Mech. 56, 695–719.Google Scholar
Monkewitz, P. A. & Nguyen, L. N. 1986 Absolute instability in the near-wake of bluff-bodies. J. Fluids and Structures 1, 165–184.Google Scholar
Ongoren, A. 1986 Unsteady structure and control of near-wakes. PhD. dissertation, Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, Pennsylvania.
Parkinson, G. V. 1974 Mathematical models of flow-induced vibrations. In Flow-Induced Structural Vibrations (ed. E. Naudascher), pp. 81–127. Springer.
Rockwell, D. 1972 External excitation of planar jets. Trans. ASME E: J. Appl. Mech. 39, 883–890.Google Scholar
Rockwell, D. 1983 Invited lecture: Oscillations of impinging shear layers. AIAA J. 21, 645–664.Google Scholar
Roshko, A. 1976 Structure of turbulent shear flows: A new look. AIAA J. 14, 1349–1357.Google Scholar
Sarpkaya, T. 1978 Fluid forces on oscillating cylinders. J. Waterways, Ports, Coastal Ocean Div., ASCE 104, 275–290.Google Scholar
Sarpkaya, T. 1979 Vortex-induced oscillations: A selective review. Trans. ASME E: J. Appl. Mech. 26, 241–258.Google Scholar
Schraub, F. A., Kline, S. J., Henry, J., Runstadler, P. W. & Little, A. 1965 Use of hydrogen bubbles for quantitative determination of time-dependent velocity fields in low-speed water flows. Trans. ASME D: J. Basic Engng 87, 429–444.Google Scholar
Staubli, T. 1981 Calculation of the vibration of an elastically mounted cylinder using experimental data from a forced oscillation. In ASME Symp. on Fluid-Structure Interaction in Turbomachinery, pp. 19–24.
Unal, M. F. & Rockwell, D. 1988 On vortex formation from a cylinder: Part 1 — The initial instability. J. Fluid Mech. 190, 491–512.Google Scholar
Wei, T. & Smith, C. R. 1986 Secondary vortices in the wake of circular cylinders. J. Fluid Mech. 169, 513–533.Google Scholar
Winant, C. D. & Browand, F. K. 1974 Vortex pairing, the mechanism of turbulent mixing layer growth at moderate Reynolds number. J. Fluid Mech. 63, 237–255.Google Scholar
Zdravkovich, M. M. 1982 Modification of vortex shedding in the synchronization range. Trans. ASME I: J. Fluids Engng 104, 513–517.Google Scholar