Journal ArticleDOI
Proximity-induced galloping of two interfering circular cylinders
A. Bokaian,F. Geoola +1 more
TLDR
In this paper, the response of a rigid two-dimensional elastically mounted smooth 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, was investigated.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.read more
Citations
More filters
Journal ArticleDOI
Vortex-induced vibrations of two cylinders in tandem arrangement in the proximity-wake interference region.
TL;DR: It is shown that even though the wake transitions to a weakly three-dimensional state when the gap flow is active, the three- dimensional modes are too weak to affect the dynamic response of the system, which is found to be identical to that obtained from the two-dimensional computations.
Journal ArticleDOI
Review of interference-induced oscillations in flow past two parallel circular cylinders in various arrangements
TL;DR: In this article, three categories of flow interference are proposed: proximity, wake and the combination of both: gap-flow-switch, wake displacement and wake galloping.
Journal ArticleDOI
Flow-Induced Oscillations of Two Cylinders in Tandem and Staggered Arrangements
Sanjay Mittal,Vinod Kumar +1 more
TL;DR: In this paper, a stabilized finite element formulation is employed to study flow-induced oscillations of a pair of equal-sized cylinders in tandem and staggered arrangement placed in uniform incompressible flow.
Journal ArticleDOI
Flow-induced vibrations of two circular cylinders in tandem arrangement. Part 1: Characteristics of vibration
TL;DR: In this article, the authors investigated the flow-induced vibration characteristics of two circular cylinders in tandem arrangement, with L/D=0.5-26, where L is the gap spacing between the cylinders and D is the cylinder diameter.
Journal ArticleDOI
Numerical simulation and experimental validation for energy harvesting of single-cylinder VIVACE converter with passive turbulence control
TL;DR: In this article, passive Turbulence Control (PTC) in the form of roughness strips is applied to enhance FIM and increase the efficiency of the VIVACE converter in harnessing marine hydrokinetic energy.
References
More filters
Book
Flow-Induced Vibration
R. D. Blevins,H. Saunders +1 more
TL;DR: In this paper, the authors focus on applications for offshore platforms and piping; wind-induced vibration of buildings, bridges, and towers; and acoustic and mechanical vibration of heat exchangers, power lines, and process ducting.
Journal ArticleDOI
Stability of a circular cylinder oscillating in uniform flow or in a wake
Y. Tanida,A. Okajima,Y. Watanabe +2 more
TL;DR: In this article, the lift and drag forces were measured on both a single circular cylinder and tandem circular cylinders in uniform flow at Reynolds numbers from 40 to 104, to investigate the stability of an oscillating cylinder.
Journal ArticleDOI
Wake-induced galloping of two interfering circular cylinders
A. Bokaian,F. Geoola +1 more
TL;DR: In this paper, fluid-dynamic instability of a smooth circular cylinder, free to oscillate laterally against linear springs in the wake from an identical stationary neighbouring body, was investigated.
Journal ArticleDOI
Fluid flow and heat transfer with two cylinders in cross flow
Ž.G Kostić,S.N Oka +1 more
TL;DR: In this article, the authors investigated the flow and heat transfer around two cylinders in cross flow (one of them in the wake of the other) and determined the distribution of the static pressure coefficients and Nusselt number on the surfaces of both cylinders by measurements.
Journal ArticleDOI
A contribution to the free-stream turbulence effect on the flow past a circular cylinder
TL;DR: In this article, the effect of free-stream turbulence on the flow past a circular cylinder was studied experimentally in the subcritical and critical regimes, and it was argued that the parameter R1·34T will control some aspects of flow past the cylinder immersed in turbulent streams.