An Experimental Study on the Control of the Vortex-Induced Vibration of a Circular Cylinder by Acoustic Excitation

Hiejima, Shinji; Kimura, Kichiro; Fujino, Yozo; Nomura, Takashi

doi:10.2208/jscej.1995.525_171

Cited by 4 publications

(2 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The numerical results (Suzuki 1999) show that the acoustic excitation at an appropriate frequency dynamically suppresses the leading edge separation and causes a change of vortex structure of a flow around an airfoil. For a circular cylinder, the most effective sound frequency in reducing the vortex-induced oscillation amplitude approximately corresponded to the transition wave frequency predicted by Wei's formula (Hiejima 1996(Hiejima , 1997.…”

Section: Introductionsupporting

confidence: 58%

TC3 Square/Cube 3

Smirnov

Voropayev

Fernando³

et al. 2006

Wind Engineers, JAWE

View full text Add to dashboard Cite

A series of laboratory experiments was conducted to investigate the formation and evolution of large vortices generated in density stratified fluids by unsteadily moving (maneuvering) bodies at relatively high body Reynolds numbers. Flow visualization and particle image velocimetry (PIV) technique were used in these large-scale experiments to clarify vorticity dynamics in the late wakes and collect data on the flow evolution. Different body maneuvers were reproduced in the experiments, including starting motion from rest, nearly steady motion with strong/weak acceleration, passive towing along the arc trajectory, and steady motion. In all these experiments, the formation of large (compare to the body diameter), long living eddies was registered in the late wake flow, whence a significant momentum is imparted to the fluid. Some of the new effects discovered in the high-Re case are the influence of internal wave radiation on momentum balance in the wake, surface signatures of stratified wakes, and transverse-propagating vortex dipoles that form during the motion of bodies in curved paths. The flow phenomena and measurements were explained using dynamic arguments and phenomenological models.KEYWORDS: wake flow, stratified fluid, self-propelled body.1 INTRODUCTION Vortical flows that are commonly observed in various fluid systems can be considered to be generated by a forcing that acts in a localized area of the fluid. A typical example is the far wake behind a body. At late times the body is far from the observer, and for mathematical modeling it may be considered as a "point" source of vorticity. As such, the details of the flow near the body can be neglected and the late wake flow structure is expected to be dependent mostly on the dominant characteristic of body forcing (force, force doublet, etc.). Steady and starting flows induced by such forcing are of definite interest and have been intensively studied in the past while achieving success in obtaining some exact and approximate analytical solutions [1][2][3][4]. This fundamental problem has demonstrated applications in stratified and other quasi-twodimensional liquid systems (e.g., shallow-water flows and soap films) where the flow is effectively two-dimensional. Numerous studies show that such liquid systems pose a remarkable property -that they "remember" the forcing history, for example, a force generates a dipolar flow and a force doublet generates quadrupolar flow [5][6][7]. The morphology (spatial organization of vorticity) of the resulting flow patterns often depends on the forcing and determines the evolution of coherent eddies.The background stratification significantly increases the complexity of the problem of compact vortical flows, and hitherto there are no analytical solutions for this case. As such,

show abstract

Section: Introductionsupporting

confidence: 58%

TC3 Square/Cube 3

Smirnov

Voropayev

Fernando³

et al. 2006

Wind Engineers, JAWE

View full text Add to dashboard Cite

show abstract

“…Hijima et al [17] investigated numerically the effect of the sound wave with specified frequency on the stability of the separated shear layer around the cylinder. In addition, experimental studies by Hijima et al [18] indicate that the vortex induced vibration of a circular cylinder can be suppressed using the stimulation of the separated shear layer by an acoustic wave with the frequency of the transition waves. Apparently, this method is examined only for small amplitude of the vortex-induced vibration.…”

Section: Introductionmentioning

confidence: 99%

Suppression of Vortex Induced Vibrations on Circular Cylinder via Boundary Layer Suction

Owis

2011

International Conference on Aerospace Sciences and Aviation Tec

View full text Add to dashboard Cite

Marine risers used to convey oil from the sea bed to the sea level, marine cables, heat exchanger pipes, civil engineering structures and aircraft wings vibrate due to the formation of the vortex streets behind these structures. The interactions between the flow oscillations and the structure give rise to complicated vibrations of the structure which could cause structural damage due to the fatigue. Numerical simulation of the vortex-induced vibrations on circular cylinders is used to investigate the possibility of suppressing these vibrations for different engineering applications. The unsteady, incompressible, two-dimensional Navier-Stokes equations are solved numerically on a structured grid using the finite difference method. The effect of flow control using the boundary layer suction for fixed or moving cylinder is investigated by applying the appropriate boundary conditions on the cylinder surface. In the current study, natural motion of the cylinder is not considered. Flow oscillations are investigated only for fixed cylinder and for forced motion of the cylinder. The results indicate that the flow oscillations are completely damped for a fixed cylinder using suction on the cylinder surface. For forced motion of the cylinder, the vortex shedding from the surface is eliminated using the boundary layer suction. The flow oscillates only due to the forced motion of the body vibrations which means that the flow oscillations can be damped completely if the cylinder is left to oscillate naturally.

show abstract

Suppression Mechanisms of the Vortex-Induced Vibration of a Circular Cylinder by Periodic Velocity Excitation

Hiejima¹,

Nomura²

2003

Doboku Gakkai Ronbunshu

View full text Add to dashboard Cite

An Experimental Study on the Control of the Vortex-Induced Vibration of a Circular Cylinder by Acoustic Excitation

Cited by 4 publications

References 19 publications

TC3 Square/Cube 3

TC3 Square/Cube 3

Suppression of Vortex Induced Vibrations on Circular Cylinder via Boundary Layer Suction

Suppression Mechanisms of the Vortex-Induced Vibration of a Circular Cylinder by Periodic Velocity Excitation

Contact Info

Product

Resources

About