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Proximity-induced galloping of two interfering circular cylinders

Published online by Cambridge University Press:  20 April 2006

A. Bokaian  and
F. Geoola
A. Bokaian
Affiliation:
Earl and Wright Ltd, Consulting Engineers, Victoria Station House. 191 Victoria Street, London SW1E 5NE
F. Geoola
Affiliation:
Department of Civil Engineering, University College London, Gower Street, London WC1E 6BT
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Abstract

Experiments were conducted to investigate the response of a rigid two-dimensional elastically mounted smooth circular cylinder, with oscillations restricted to a plane normal to the incident flow, as influenced by the vicinity of an identical fixed body placed inside the wake. The static lift and drag coefficients, as well as the vibration amplitude and frequency of the upstream cylinder as functions of relative position of the pair of cylinders are given. Most measurements were carried out under two conditions of free-stream turbulence. Whilst turbulence decreased the magnitude of drag coefficients, it had no appreciable effect on lift coefficients. The forces on the upstream body were found to be influenced by the proximity to the downstream one in a significant way only when the streamwise spacing is less than two diameters.

In the dynamic tests, two kinds of instability, namely a vortex-resonance and galloping, were observed, with the latter only occurring when the downstream cylinder was well submerged in the near wake of the upstream one. The vortex-shedding frequency was always found to lock to oscillation frequency. Whereas the vibration characteristics remained essentially unaffected with changing turbulence intensity, the galloping amplitudes were observed to be sensitive to cylinders’ aspect ratio. A quasi-steady theory was developed to predict the galloping behaviour.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 146 , September 1984 , pp. 417 - 449
Copyright
© 1984 Cambridge University Press

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References

Blevins, R. D. 1977 Flow-Induced Vibration. Van Nostrand Reinhold.
Bokaian, A. & Geoola, F. 1984a Hydroelastic instabilities of square cylinders. J. Sound Vib. 92, 117–141.Google Scholar
Bokaian, A. & Geoola, F. 1984b Vortex-shedding from two interfering circular cylinders. Tech. Note, J. Engng Mech. Div. ASCE 110, 623–628.Google Scholar
Bokaian, A. & Geoola, F. 1984c Wake-induced galloping of two interfering circular cylinders. J. Fluid Mech. 146, 383–415.Google Scholar
Hayes, I. H. 1970 Numerical Approximation to Functions and Data. The Athlone Press.
Kiya, M., Suzuki, Y., Arie, M. & Hagino, M. 1982 A contribution to the free-stream turbulence effect on the flow past a circular cylinder. J. Fluid Mech. 115, 151–164.Google Scholar
Kostic, Z. G. & Oka, S. N. 1972 Fluid flow and heat transfer with two cylinders in cross flow. Intl J. Heat Mass Transfer 15, 279–299.Google Scholar
Krylov, N. & Bogoliubov, N. 1949 Introduction to Non-Linear Mechanics. Princeton University Press.
Ruscheweyh, H. P. 1983 Aeroelastic interference effects between slender structures. In Proc. 6th Intl Conf. on Wind Engng. Gold Coast, Australia and Auckland, N.Z.
Tanida, Y., Okajima, A. & Watanabe, Y. 1973 Stability of a circular cylinder oscillating in uniform flow or in a wake. J. Fluid Mech. 61, 769–784.Google Scholar
Wardlaw, R. L. & Cooper, K. R. 1973 A wind tunnel investigation of the steady aerodynamic forces on smooth and stranded twin bundled power conductors for the Aluminium Company of America. Natl Aero. Estab., Canada, LTR-LA-117.
Wawzonek, M. A. & Parkinson, G. V. 1979 Combined effects of galloping instability and vortex-resonance. In Proc. 5th Intl Conf. on Wind Engng, Fort Collins, Colorado, vol. 2, pp. 673–684.
Zdravkovich, M. M. 1974 Flow induced vibrations of two cylinders in tandem, and their suppression. In Proc. Intl Symp. on Flow Structural Vibrations, Karlsruhe 1972, pp. 631–639. Springer.