Hostname: page-component-8448b6f56d-m8qmq Total loading time: 0 Render date: 2024-04-23T09:57:37.923Z Has data issue: false hasContentIssue false
  • English
  • Français

Wake-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
Get access Rights & Permissions [Opens in a new window]

Abstract

Measurements are presented of fluid-dynamic instability of a smooth circular cylinder, free to oscillate laterally against linear springs in the wake from an identical stationary neighbouring body. The observations also encompassed determination of static forces on the downstream cylinder as functions of relative position of the cylinder pair. Most of the experiments were performed under two conditions of free-stream turbulence. Static tests indicated that both the drag coefficient and the Strouhal number of the downstream body are continuous functions of its relative position. The drag forces were found to be negative at small gaps. It was observed that the transverse extent of the force field increases with increasing streamwise gap.

In the dynamic experiments, depending on the cylinders’ separation and structural damping, the cylinder exhibited a vortex-resonance, or a galloping, or a combined vortex-resonance and galloping, or a separated vortex-resonance and galloping. Whilst the characteristics of wake-excited motion were found to be essentially unaffected by a limited change in free-stream turbulence intensity, the galloping amplitudes were observed to be sensitive to the cylinders’ aspect ratio. An increase in the stability parameter caused significant effects on the cylinder response in amplitude domain. Wake observations behind the oscillating body indicated that in vortex lock-in the frequency of vortex-shedding locked to vibration frequency, but during small-amplitude galloping motion the shedding frequency behaved as if the cylinder was stationary.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 146 , September 1984 , pp. 383 - 415
Copyright
© 1984 Cambridge University Press

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

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
Chen, S. S., Wambsganss, M. W. & Jendrzejczyk, J. A. 1976 Added mass and damping of a vibrating rod in confined viscous fluids. Trans. ASME E: J. Appl. Mech. 98, 325–329.Google Scholar
Cooper, K. R. 1974 Wind tunnel measurements of the steady aerodynamic forces on a smooth circular cylinder immersed in the wake of an identical cylinder. Natl Aero. Estab., Canada, LTR-LA-119.
Cooper, K. R. & Wardlaw, R. L. 1971 Aeroelastic instabilities in wake. In Proc. Intl Symp. on Wind Effects on Buildings and Structures, Tokyo; Paper IV. 1, pp. 647–655.
Hori, E. 1959 Experiments on flow around a pair of parallel circular cylinders. In Proc. 9th Japan Natl Congr. Appl. Mech., Tokyo, pp. 231–234.
Jendrzejczyk, J. A., Chen, S. S. & Wambsganss, M. W. 1979 Dynamic responses of a pair of circular tubes subjected to liquid cross flow. J. Sound Vib. 67, 263–273.Google Scholar
King, R. & Johns, D. J. 1976 Wake interaction experiments with two flexible circular cylinders in flowing water. J. Sound Vib. 45, 259–283.Google Scholar
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
Price, S. J. 1975 Wake-induced flutter of power transmission conductors. J. Sound Vib. 38, 125–147.Google Scholar
Price, S. J. 1976 The origin and nature of the lift force on the leeward of two bluff bodies. Aero. Q. 26, 154–168.Google Scholar
Roberts, B. W. 1966 Low frequency aeroelastic vibrations in a cascade of circular cylinders. Mech. Engng Sci. Monograph no. 4.Google Scholar
Ruscheweyh, H. P. 1983 Aeroelastic interference effects between slender structures. In Proc. 6th Intl Conf. on Wind Engng, Gold Coast, Australia & Auckland, N.Z.
Simpson, A. 1971 On the flutter of a smooth circular cylinder in a wake. Aero. Q. 22, 25–41.Google Scholar
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
Vickery, B. J. & Watkins, R. D. 1964 Flow-induced vibrations of cylindrical structures. In Proc. 1st Australian Conf. on Hydraul. and Fluid Mech. (ed. R. Silvester), pp. 213–239. Pergamon.
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.
Yang, C. I. & Moran, T. J. 1979 Calculations of added mass and damping coefficients for hexagonal cylinders in a confined viscous fluid. In Flow-Induced Vibrations (ed. S. S. Chen & M. D. Bernstein), pp. 97–103. ASME.
Zdravkovich, M. M. 1974 Flow induced vibrations of two cylinders in tandem, and their suppression. In Proc. Intl Symp. Flow Induced Structural Vibrations, Karlsruhe 1972, pp. 631–639. Springer.
Zdravkovich, M. M. 1977 Review of flow interference between two circular cylinders in various arrangements. Trans. ASME I: J. Fluids Engng 99, 618–633.Google Scholar
Zdravkovich, M. M. 1982 Flow-induced oscillation of two interfering circular cylinders. In Intl Conf. on Flow-Induced Vibrations in Fluid Engng, Reading, England, pp. 141–154.