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Showing papers on "Vortex-induced vibration published in 2003"


Journal ArticleDOI
TL;DR: In this article, the authors studied the response of an elastically mounted cylinder, which is free to move in two degrees of freedom in a fluid flow, and which has low mass and damping.

200 citations


Journal ArticleDOI
TL;DR: In this article, a non-linear fluid force model for a freely vibrating cylinder in a cross flow was developed based on an iterative process and the modal analysis approach, which can be evaluated from measured vibration data with the help of the auto-regressive moving averaging (ARMA) technique.

66 citations


Journal ArticleDOI
TL;DR: In this article, a model of a heat exchanger tube bundle subjected to a cross-flow of refrigerant 11 was used to determine the flow-induced vibration (FIV) response and fluidelastic stability threshold.

42 citations


Journal ArticleDOI
TL;DR: In this paper, an accelerometer on each cylinder was used to measure the vortex-induced vibration response, which primarily varied between the third and seventh transverse bending modes, revealing some interesting relationships between the responses of the two cylinders when plotted against the upstream cylinder displacements.

39 citations


Journal ArticleDOI
TL;DR: In this paper, a coupled fluid structure interaction problem is analyzed using semi-analytical finite element method involving composite cylindrical shells conveying hot fluid for free vibration and buckling behavior.

34 citations


Journal ArticleDOI
Usik Lee1, Hyuck-Jin Oh1
TL;DR: In this article, a spectral element model for the pipeline conveying steady internal fluid is presented, which can provide very accurate solutions using only one finite element for the uniform structure member, regardless of its length.

31 citations


Proceedings ArticleDOI
01 Jan 2003
TL;DR: In this paper, a force-feedback control system for VIV experiments is designed and evaluated for the purpose of achieving high accuracy free vibration tests, and specific methods for minimizing the combined effect of mass and damping using control system fundamentals are described.
Abstract: A force-feedback control system for VIV experiments is designed and evaluated for the purpose of achieving high accuracy free vibration tests. Through an organized approach, this work details specific methods for minimizing the combined effect of mass and damping using control system fundamentals. The dynamics of the closed-loop system are analyzed, a numerical model constructed and a control scheme is chosen and implemented in real-time. The control system performance is evaluated by performing frequency response tests in air. Free vibrations of a smooth aluminum cylinder are performed at Reynolds number 19000. Test series with damping ratios of one, two and five percent are performed, all with nondimensional mass four. A peak amplitude ratio of 1.15 is observed for the case of lowest damping. Forced vibration tests with the same setup are performed and compared to the free vibration results, giving consistent results.Copyright © 2003 by ASME

22 citations


Journal ArticleDOI
TL;DR: In this paper, a computationally inexpensive method of numerical simulation for the unsteady flow through a rigid normal triangular tube array which determines both the frequency of vortex shedding and the instantaneous flow structure is presented.

22 citations


Journal ArticleDOI
17 Jul 2003-Nature

20 citations


Journal ArticleDOI
TL;DR: In this paper, the fluid-structure interaction between the fluid and the fin structure is considered for an increasing fluid velocity up to Ma 2.0 and for stationary flow conditions at Ma 1.0 using ADINA/ADINA-F.

14 citations


Journal ArticleDOI
TL;DR: The Foinaven Umbilical Monitoring System (FUMS) has been provided to measure the stresses in a subsea umbilical of the Foinven floating production facility as mentioned in this paper.

Proceedings ArticleDOI
01 Jan 2003
TL;DR: Vandiver et al. as discussed by the authors evaluated the effect of placing staggered buoyancy along a marine riser and found that the added buoyancy may decrease fatigue damage rate, provided that measures are taken to minimize increases in the ratio of mass per unit length of the riser to mean tension.
Abstract: This paper presents results from a 1997 joint industry project arranged by MIT and Marintek. The data was taken at the Marintek towing tank in Trondheim, Norway. The primary goal of the project was to evaluate how flow-induced vibration of a marine riser is affected by placement of staggered buoyancy along the riser. The riser was subjected to both sheared and uniform flow, and was tested with various configurations of buoyancy. Cross-flow measurements of acceleration were analyzed to determine dominant response frequency and vibration amplitude. Tension and flow velocity were also measured. It is shown that a riser with 50% staggered buoyancy or greater will have response dominated by vortex shedding on the large diameter buoyancy modules. It is also found that the addition of buoyancy may decrease fatigue damage rate, provided that measures are taken to minimize increases in the ratio of mass per unit length of the riser to mean tension. It is primarily the decrease in vortex shedding frequency due to the larger diameter that accounts for any reduction in fatigue damage rate. Unfortunately, the benefits gained from the addition of buoyancy may be undone by the typical increase in mass and decrease in riser tension that occur when buoyancy is present. Two secondary goals of this paper are to evaluate the importance of estimating in-line acceleration when computing the fatigue damage rate, and to evaluate how much the higher harmonics of the vortex shedding frequency contribute to the fatigue damage rate. To estimate the importance of in-line measurements, these measurements are used to perform vector rotation, from which is found the direction and magnitude along which the riser experiences the most damage. This damage rate is then compared to the cross flow damage rate. To evaluate how much the higher harmonics of the vortex shedding frequency contribute to the damage rate, a comparison is made between the following two calculations of the damage rate. First, the damage is calculated using frequencies up to the primary cross flow and in-line vibration frequencies. Then, it is calculated from frequencies including up to the fourth harmonic of the vortex shedding frequency. In this secondary analysis, it is found that the cross flow damage parameter is a good estimate of the maximum damage parameter in the majority of cases; however, in a substantial number of tests the rotated maximum damage parameter is much larger than the cross flow damage parameter. It is also found that in the majority of tests the higher harmonics of the vortex shedding frequency make up more than half of the total contribution to the fatigue damage rate. Thesis Supervisor: J. Kim Vandiver Titles: Professor of Ocean Engineering, Director Edgerton Center, Dean of Undergraduate Research

Journal ArticleDOI
TL;DR: In this article, the lateral components of the turbulent fluid force per unit-length cross-spectral densities in a bundle of cylinders are obtained by the integration of differential wall-pressure fluctuations around the circumferences of the cylinders.

Journal ArticleDOI
TL;DR: In this paper, the Strouhal number was used to measure the synchronized vibrations of a circular cylinder in a water cross flow at supercritical Reynolds numbers, at a reduced velocity of 1.1.
Abstract: Synchronized vibrations of a circular cylinder in a water cross flow at supercritical Reynolds numbers were measured. Turbulence intensities were varied to investigate the effect of the Strouhal number on the synchronization range. Self-excited vibration in the drag direction due to symmetrical vortex shedding began only when the Strouhal number was about 0.29, at a reduced velocity of 1.1. The reduced velocities at the beginning of lock-in vibrations caused by Karman vortex shedding decreased from 1.5 to 1.1 in the drag direction and from 2.7 to 2.2 in the lift direction, as the Strouhal number increased from 0.29 to 0.48.

Journal ArticleDOI
TL;DR: In this paper, a nonlinear cable/fluid model is discussed that captures both fast (small amplitude) motions due to VIV and slow (large amplitude) motion due to drift.
Abstract: Analytical studies of vortex-induced vibration (VIV) of cables during lock-in have considered small amplitude and relatively fast dynamic responses about an equilibrium configuration. However, this equilibrium may change as a result of the significantly increased mean drag created during lock-in. In response to increased drag, the cable may slowly drift downstream causing appreciable changes in cable geometry and tension. The resonance conditions for lock-in may be preserved during this slow drift or they may be disrupted. A nonlinear cable/fluid model is discussed that captures both fast (small amplitude) motions due to VIV and slow (large amplitude) motions due to drift.


Journal ArticleDOI
TL;DR: In this article, a numerical technique that can prevent the mesh from severe distortion in flow-induced vibration calculations is described, where an orthogonal transformed space that is related to the physical space through a Laplacian equation is introduced.

Journal Article
TL;DR: In this paper, the authors investigated the flow around a single cylinder free to vibrate in the transverse direction using the 2-D Discrete Vortex Method and found that the maximum calculated amplitude of induced vibration is lower than the experimental ones.
Abstract: The flow around a single cylinder free to vibrate in the transverse direction is investigated employing the 2-D Discrete Vortex Method. The simulations are carried out for a mass parameter and Reynolds number that are typical of the flow around an oil extraction riser. Results of amplitude of induced vibration as a function of reduced velocity are compared with experimental data from Khalak and Williamson (1996). It is found that the maximum calculated amplitudes of vibration are lower than the experimental ones, but the simulations with the 2-D Discrete Vortex Method proved to be inexpensive and well suited to qualitative studies and the development of strip-theory solvers capable of simulating a long marine riser installed in ultra deep waters.

01 Jan 2003
TL;DR: In this article, the 3D flow in a 4:1 sudden square-square contraction for a viscoelastic shear-thinning fluid under conditions of negligible inertia show provocative flow patterns.
Abstract: Visualizations of the 3-D flow in a 4:1 sudden square-square contraction for a viscoelastic shear-thinning fluid under conditions of negligible inertia show provocative flow patterns. Whereas for a Newtonian fluid the vortex length remains unchanged, with the non-Newtonian fluid there is a dramatic increase in vortex length with fluid elasticity leading to unstable periodic flow at higher flow rates. In the steady flow regime the vortices are not closed and fluid particles enter the middle-plane vortex, rotate towards its eye, drift to the corner plane vortex, rotate to its periphery and exit to the downstream duct, a dynamic process that is opposite that found with Newtonian fluids. The periodic flow was characterised by a constant Strouhal number of 0.5.

Book ChapterDOI
TL;DR: In this paper, three cylindrical bodies with different cross sectional configurations, i.e., a circular, semi-circular and triangular cylinder, are used as the test cylinders, in order to investigate the influence of movement of separation point on the Karman vortex excitation.
Abstract: Three cylindrical bodies with different cross sectional configurations, i.e. a circular, semi-circular and triangular cylinder, are used as the test cylinders, in order to investigate the influence of movement of separation point on the Karman vortex excitation. The cylinders were supported elastically by plate springs. The synchronization of Karman vortex shedding occurs on all three cylinders over almost equal ranges of oscillation amplitude and frequency given by the mechanical oscillator. However, the Karman vortex excitation behavior differs drastically among the three cylinders in spite that the cylinders are supported elastically with virtually equal structure parameters.


Journal ArticleDOI
TL;DR: In this article, interference effects on vortex-induced vibrations of two side-by-side elastic cylinders, fixed at both ends (with no deflection and displacement) in a cross-flow, were experimentally investigated.
Abstract: Interference effects on vortex-induced vibrations of two side-by-side elastic cylinders, fixed at both ends (with no deflection and displacement) in a cross-flow, were experimentally investigated. The dynamic responses of the cylinders were measured using two fiberoptic Bragg grating (FBG) sensors. Simultaneously, a single hot wire was used to measure the velocity in the wake. It has been previously observed that violent resonance occurs when transverse cylinder spacing ratio,T/d, is either large (.2.0) or small (,1.2), but not for intermediate cylinder spacing, i.e., T/d51.2;2.0. This work aims to improve the understanding of the physics behind this observation, and mostly focuses on the fluid-structure interaction in the flow regime of intermediate cylinder spacing. It is well known that in this flow regime the fluid dynamics around one cylinder is totally different from that around the other; the vortical structures are characterized by different dominant frequencies, i.e., about 0.1 and 0.3 (normalized), respectively. The present data indicates that the vortical structures at these frequencies are either weak or different in the formation process from the case of T/d .2.0 or T/d,1.2, thus resulting in a weak excitation and subsequently an absence of violent resonance. The interrelationship between the vortical structures generated by the two cylinders is also investigated and interpreted in terms of different vortex generation mechanisms. The different fluid dynamics around each cylinder is further found to be responsible for a deviation between the natural frequencies of the combined fluid-cylinder system associated with each cylinder. @DOI: 10.1115/1.1568360#

Journal ArticleDOI
TL;DR: In this paper, the authors deal with nonlinear analyses of sheet flutter in a narrow passage caused by fluid-structure interaction, and the behavior of sheet when flow velocity exceeds critical flow velocity.
Abstract: This paper deals with nonlinear analyses of sheet flutter in a narrow passage caused by fluid-structure interaction. Attention is paid to the behavior of sheet when flow velocity exceeds critical flow velocity. With discretization, the sheet is modeled as a combination of mass less beam elements, springs and discrete mass particles, in which the mass of each particle and spring coefficients are calculated based on the beam model. Nonlinear fluid forces acting on the mass particles are formulated then coupled with equations of motions of structure. After that the behavior of large-amplitude vibration of cantilevered sheet is simulated using numerical computation, showing that vibration of sheet grows into a limit cycle oscillation then becomes unstable with increasing flow velocity.

Journal ArticleDOI
01 Jun 2003
TL;DR: In this article, a variational-based approach is developed to provide a framework for the study of flow-induced vibration, which includes experimentally derived functions, but there are no ad hoc assumptions or a priori equations that are fit to data.
Abstract: Abstract A variational-based approach is developed to provide a framework for the study of flow-induced vibration. While the model includes experimentally derived functions, there are no ad hoc assumptions or a priori equations that are fit to data.


Proceedings ArticleDOI
01 Jan 2003
TL;DR: In this paper, the authors describe the transient flow in a single-blade sewage water pump and calculate the hydrodynamic stimulation forces from the known transient flow field, which can be classified into pressure and friction forces on several orders of magnitude.
Abstract: The extreme vibrations of sewage water pumps with single-blade impellers are induced mainly by interaction of the flow in the impeller and the casing. The resulting periodically unsteady forces affect the impeller and produce radial deflections of the pump shaft. These oscillations of the rotor are transferred to the pump casing and attached pipes. They can be recognized as vibrations at the bearing blocks or at the pump casing. The present contribution describes the investigation of the transient flow in a sewage water pump. The three-dimensional, viscous, unsteady flow in a pump with a single blade impeller is determined by numerical simulation. After that the hydrodynamic stimulation forces are calculated from the so known transient flow field. The forces can be classified into pressure and friction forces. The pressure forces usually exceed the friction forces on several orders of magnitude. A separate view on the fluid-wetted impeller surfaces shows that the pressure forces acting on the blade are clearly larger than the forces at the hub and at the shroud. So they are decisive for the vibration amplitudes of single-blade sewage water pumps. By a following dynamic analysis of the pump rotor using a commercial Finite-Element-Method (FEM) the resulting vibration amplitudes are determined for several operating points. With the known pressure field and the calculated vibration amplitudes the vibration behavior of sewage water pumps can be influenced during the design by changing the relevant construction parameters.Copyright © 2003 by ASME




Proceedings ArticleDOI
Nariaki Horinouchi1, Yoshihiro Kato1, Tsuguo Kondoh1, Tomohiro Yamada1, Osamu Ninomiya1 
27 Oct 2003
TL;DR: In this paper, a technique has been developed that uses unsteady flow simulation to evaluate mirror vibration quantitatively at the drawing stage, and the results obtained through CFD show a high degree of correlation with those obtained in actual driving tests.
Abstract: A technique has been developed that uses unsteady flow simulation to evaluate mirror vibration quantitatively at the drawing stage Studies made in actual driving tests of the contributions of different inputs to mirror vibration have confirmed that the contribution of fluid force is large, so a visualization of the structure of the external rearview mirror wake was done using PIV The results made it clear that the vibration imparted to the mirror surface by air flow excites the natural vibration mode of the mirror surface, thereby causing the mirror to vibrate Mirror vibration performance was evaluated by means of unsteady flow simulation using the moment PSD as a substitute characteristic (The moment PSD was obtained by a frequency analysis of the changes over time in the moment generated in the mirror surface by the fluid force) The results obtained through CFD show a high degree of correlation with those obtained In actual driving tests (A) For the covering abstract see ITRD E121867