Numerical Method to Calculate Flow-Induced Vibration in Turbulent Flow. 2nd Report, Analysis of Vortex-Induced Vibration of Elastically Supported Cylinder and Investigation of Vibration Mechanism.

Abstract Purpose This study elucidated the effect of an inclined spring arrangement on the flow-induced vibration of a circular cylinder to understand if the effect enhances the harnessing of the energy of fluid flows. Method An experiment was conducted on a circulating water channel. A circular cylinder was partially submerged. It was elastically supported by two springs whose longitudinal directions were varied. With the speed of the water flow varied, the vibrations of the circular cylinder were measured. The measured vibrations were interpreted by la linear dynamic model. Results and discussion In a few cases, a jump in response amplitudes from zero to the maximum was observed with the spring inclination at reduced velocities of 6 to 7, whereas gradually increasing response amplitudes were observed in other cases. The inclined spring arrangement achieved greater velocity amplitudes than in cases without spring inclination. A theoretical evaluation of the measured responses indicates that the effect of the inclined springs was caused by geometric nonlinearity; the effect would be more prominent by employing a longer moment lever.

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Surface Roughness Effects on Circular Cylinders at High Reynolds Numbers

5th International Symposium on Fluid Structure International, Aeroeslasticity, and Flow Induced Vibration and Noise ◽

10.1115/imece2002-32160 ◽

2002 ◽

Author(s):

M. Eaddy ◽

W. H. Melbourne ◽

J. Sheridan

Keyword(s):

Surface Roughness ◽

Reynolds Numbers ◽

Circular Cylinders ◽

Flow Induced Vibration ◽

Roughness Effects ◽

Vortex Induced Vibration ◽

Smooth Cylinder ◽

Lift Forces ◽

High Reynolds ◽

Effect Of Surface

The problem of flow-induced vibration has been studied extensively. However, much of this research has focused on the smooth cylinder to gain an understanding of the mechanisms that cause vortex-induced vibration. In this paper results of an investigation of the effect of surface roughness on the cross-wind forces are presented. Measurements of the sectional RMS fluctuating lift forces and the axial correlation of the pressures for Reynolds numbers from 1 × 105 to 1.4 × 106 are given. It was found that surface roughness significantly increased the axial correlation of the pressures to similar values found at high subcritical Reynolds numbers. There was little effect of the surface roughness on the sectional lift forces. The improved correlation of the vortex shedding means rough cylinders will be subject to larger cross-wind forces and an increased possibility of vortex-induced vibration compared to smooth cylinders.

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Experimental Study on Flow-Induced Vibration of Floating Squared Section Cylinders With Low Aspect Ratio: Part I — Effects of Incidence Angle

Volume 2: CFD and VIV ◽

10.1115/omae2015-41008 ◽

2015 ◽

Cited By ~ 3

Author(s):

Rodolfo T. Gonçalves ◽

Dênnis M. Gambarine ◽

Felipe P. Figueiredo ◽

Fábio V. Amorim ◽

André L. C. Fujarra

Keyword(s):

Aspect Ratio ◽

Incidence Angle ◽

Ocean Basin ◽

Circular Cylinders ◽

Structural Damping ◽

Flow Induced Vibration ◽

Double Frequency ◽

Low Aspect Ratio ◽

Aspect Ratios ◽

Elastically Supported

Experiments regarding flow-induced vibration on floating squared section cylinders with low aspect ratio were carried out in an ocean basin with rotating-arm apparatus. The floating squared section cylinders were elastically supported by a set of linear springs to provide low structural damping to the system. Three different aspect ratios were tested, namely L/D = 1.0, 2.0 and 3.0, and two different incidence angles, namely 0 and 45 degrees. The aims were to understanding the flow-induced vibration around single columns of multi-column platforms, such as semi-submersible and TLP. VIV on circular cylinders were also carried out to compare the results. The range of Reynolds number covered was 2,000 < Re < 27,000. The in-line and transverse amplitude results showed to be higher for 45-degree incidence compared with 0-degree, but the maximum amplitudes for squared section cylinders were lower compared with the circular ones. The double frequency in the in-line motion was not verified as in circular cylinders. The yaw amplitudes cannot be neglected for squared section cylinders, maximum yaw amplitudes around 10 degrees were observed for reduced velocities up to 15.

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Experimental Study on Flow-Induced Vibration of Floating Squared Section Cylinders With Low Aspect Ratio: Part II — Effects of Rounded Edges

Volume 2: CFD and VIV ◽

10.1115/omae2016-54813 ◽

2016 ◽

Cited By ~ 2

Author(s):

Rodolfo T. Gonçalves ◽

Dennis M. Gambarine ◽

Aline M. Momenti ◽

Felipe P. Figueiredo ◽

André L. C. Fujarra

Keyword(s):

Aspect Ratio ◽

Reynolds Numbers ◽

Ocean Basin ◽

Separation Point ◽

Flow Induced Vibration ◽

Low Aspect Ratio ◽

Aspect Ratios ◽

Significant Difference ◽

Flow Induced Vibrations ◽

Elastically Supported

Experiments regarding flow-induced vibration on floating rounded squared section cylinders with low aspect ratio were carried out in an ocean basin equipped with a rotating-arm apparatus. Floating squared section cylinders with rounded edges and aspect ratios of L/D = 2.0 were elastically supported by a set of linear springs in order to provide low structural damping to the system. Two different incidence angles were tested, namely 0 and 45 degrees. The Reynolds numbers covered the range from 2,000 to 30,000. The aim was to understand the flow-induced vibrations around single columns, gathering information for further understanding the causes for the Vortex-Induced Motions in semi-submersible and TLP platforms. Experiments on circular and squared sections cylinders (without rounded edges) were also carried out to compare the results with the rounded square section cylinders (with rounded edges). The amplitude results for in-line, transverse and yaw amplitude for 0-degree models showed to be higher for squared section cylinders compared to those for the rounded square section cylinders. No significant difference between the 45-degree models was observed. The results of ratio between frequency of motion in the transverse direction and natural frequency in still water confirmed the vortex-induced vibration behavior for the squared and rounded square section cylinders for 45-degree incidence; and also the galloping characteristics for 0-degree incidence cases. The rounded effect on the square section cylinders showed to be important only for reduced velocity larger than 8, which is probably related to the position of the separation point that changes around the rounded edge, behavior that did not occurr for the squared edge that fixed the separation point for any reduced velocity.

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Direct Numerical Simulation of a Turbulent Flow on an Oscillating Wall Using Cut-Cell Based Immersed Boundary Method

Volume 4: Computational Fluid Dynamics (CFD) and Coupled Codes; Decontamination and Decommissioning, Radiation Protection, Shielding, and Waste Management; Workforce Development, Nuclear Education and Public Acceptance; Mitigation Strategies for Beyond Design Basis Events; Risk Management ◽

10.1115/icone24-61000 ◽

2016 ◽

Author(s):

Chiaki Kino

Keyword(s):

Turbulent Flow ◽

Nuclear Power ◽

Power Plants ◽

Separated Flow ◽

Immersed Boundary ◽

Turbulent Structures ◽

Flow Induced Vibration ◽

Production Term ◽

Large Eddy Simulation Model ◽

Wide Range

The flow-induced vibration of a pipe is an important issue in various engineering fields, and this phenomenon is widely observed in nuclear power plants. Although turbulent structures play important roles in the velocity and pressure fields in a pipe, only a few studies have been conducted on the turbulent flow on an oscillating wall. In this study, direct numerical simulations were conducted to establish a large eddy simulation model for a turbulent flow on an oscillating wall and scrutinize the energy transfer between the grid scale (GS) and sub-grid scale (SGS). Although energy is generally transferred from the GS to SGS (forward scatter), it is likely that energy is transferred from the SGS to GS (backward scatter) under specific conditions. The present numerical results indicated that backward scatter exists in the production term in the case of a static wavy wall. On the other hand, such backward scatter could not be observed in the case of an oscillating wall. It is well known that separated flows and backward flows are generated behind the crest. Stronger backward flows accelerate the main flow and enhance the velocity gradients in a wide range behind the crest. In the case of an oscillating wall, the development of separated flow is immature because the shape of the wall is not fixed. Eventually, the backward scatter is deemed to be suppressed.

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206 Flow-induced Vibration of an Elastically Supported Cylinder Having Nonlinearity

The Proceedings of the Dynamics & Design Conference ◽

10.1299/jsmedmc.2009._206-1_ ◽

2009 ◽

Vol 2009 (0) ◽

pp. _206-1_-_206-6_

Author(s):

Yukinori Kobayashi ◽

Yuhei Takeshita ◽

Subekti ◽

Yohei Hoshino ◽

Takanori Emaru

Keyword(s):

Flow Induced Vibration ◽

Elastically Supported

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A Numerical Simulation of Vortex Induced Vibration on a Elastically Supported Circular Rigid Cylinder at Moderate Reynolds Numbers

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2008-61003 ◽

2008 ◽

Cited By ~ 1

Author(s):

Jean-Franc¸ois Sigrist ◽

Cyrille Allery ◽

Claudine Beghein

Keyword(s):

Numerical Simulation ◽

Fluid Flow ◽

Circular Cylinder ◽

Finite Volume ◽

Vortex Shedding ◽

Numerical Study ◽

Reynolds Numbers ◽

Forced Oscillations ◽

Vortex Induced Vibration ◽

Elastically Supported

The present paper is the sequel of a previously published study which is concerned with the numerical simulation of vortex-induced-vibration (VIV) on an elastically supported rigid circular cylinder in a fluid cross-flow (A. Placzek, J.F. Sigrist, A. Hamdouni; Numerical Simulation of Vortex Shedding Past a Circular Cylinder at Low Reynolds Number with Finite Volume Technique. Part I: Forced Oscillations, Part II: Flow Induced Vibrations; Pressure Vessel and Piping, San Antonio, 22–26 July 2007). Such a problem has been thoroughly studied over the past years, both from the experimental and numerical points of view, because of its theoretical and practical interest in the understanding on flow-induced vibration problems. In this context, the present paper aims at exposing a numerical study based on a fully coupled fluid-structure simulation. The numerical technique is based on a finite volume discretisation of the fluid flow equations together with i) a re-meshing algorithm to account for the cylinder motion ii) a projection subroutine to compute the forces induced by the fluid on the cylinder and iii) a coupling procedure to describe the energy exchanges between the fluid flow and solid motion. The study is restricted to moderate Reynolds numbers (Re∼2.000–10.000) and is performed with an industrial CFD code. Numerical results are compared with existing literature on the subject, both in terms of cylinder amplitude motion and fluid vortex shedding modes. Ongoing numerical studies with different numerical techniques, such as ROM (Reduced Order Models)-based methods, will complete the approach and will be published in next PVP conference. These numerical simulations are proposed for code validation purposes prior to industrial applications in tube bundle configuration.

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