Two-degree-of-freedom vortex-induced vibration of a pivoted cylinder below critical mass ratio

Leong, Chia Min; Wei, Timothy

doi:10.1098/rspa.2007.0166

Cited by 20 publications

(14 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The phase angles with the flow velocities of 0.1, 0.2, and 0.3 m/s are 60°, 200°, and 137°, respectively. Similar to the results of a previous study [25], trajectory shapes appear as crescent shapes when the flow velocity is 0.1 m/s, and the phase angle is 90°. The trajectory shapes appear as a figure eight when the flow velocity is 0.2 m/s, and the phase angle is 200°.…”

Section: Discussionsupporting

confidence: 80%

“…Thus, we can see that the dominant vibration frequency is larger than the riser natural frequency. Moreover, the initial deformation in the IL direction and vibration amplitude cause an increasing flow velocity [25]. Accordingly, the real-time natural frequency with flow velocity of 0.3 m/s during the VIV is significantly larger than that in still water.…”

Section: Discussionmentioning

confidence: 90%

“…The phenomenon is caused by that the periodic variations in drilling riser tension induced by the vibrations in both two directions. While the drilling riser vibrates in the CF direction, riser tension will also vary with vibration frequency, resulting in the deformation of the riser [24], [25]. The VIV characteristics are determined mainly by tension and bending stiffness.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental study of vortex-induced vibration for drilling risers under uniform flow current

Mao¹,

Liu²,

Zhou³

et al. 2017

J. vibroeng.

View full text Add to dashboard Cite

Abstract. An experiment was conducted in a deep water basin to investigate the vortex-induced vibration mechanism of a drilling riser. Various measurements were obtained by the fiber Bragg grating strain sensors, and data was analyzed by modal analysis method. Results show that the vibration mode of the drilling riser increases with the increasing flow velocity, and the vibration amplitude in the CF direction is larger than that in the IL direction. The vibrations in the CF and IL directions interact and mutually affect each other. The vibration mode in the IL direction is usually larger than that in the CF direction as the dominant vibration frequency is twice of that in the CF direction. Higher stresses may occur rather in the IL direction than in the CF direction. Hence, fatigue induced by the IL direction should also be taken into consideration when analyzing the fatigue life of a drilling riser. The three-time harmonic appears, and the phenomenon becomes more obvious as the flow velocity increased for the effect of the "2T" wake mode under the experiment condition. Displacement trajectories are significantly influenced by dominant vibration frequency and phase angle between the CF and IL directions. Crescent shapes, figure-eight, and inclined figure-eight are appeared in the experiment with the increasing flow velocity.

show abstract

Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental study of vortex-induced vibration for drilling risers under uniform flow current

Mao¹,

Liu²,

Zhou³

et al. 2017

J. vibroeng.

View full text Add to dashboard Cite

show abstract

“…One such example is the 'vortex-induced vibration' of offshore structures encountered in exploration and extraction of petroleum from sea beds; marine cables, pipelines, risers, platforms, etc., can be excited into significant vibration by sea currents and waves and dealing with its consequences has provided impetus and funding for concentrated research on the problem over the last few decades. Some relatively recent fundamental studies have highlighted the importance of added mass in vortex-induced vibration and increased interest in this topic [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Added mass of a circular cylinder oscillating in a free stream

Konstantinidis

2013

Proc. R. Soc. A.

View full text Add to dashboard Cite

The fundamental understanding of the added mass phenomenon associated with the motion of a solid body relative to a fluid is revisited. This paper focuses on the two-dimensional flow around a circular cylinder oscillating transversely in a free stream. A virtual experiment reveals that the classical approach to this problem leads to a paradox. The inertial force is derived afresh based on analysis of the motion in a frame of reference attached to the cylinder centroid, which overcomes the paradox in the classical formulation. It is shown that the inertial force depends not only on the acceleration of the cylinder per se, but also on the relative motion between body and fluid embodied in a parameter called alpha, α, which represents the ratio of the maximum transverse velocity of the cylinder to the free-stream velocity; the induced inertial force is directionally varying and non-harmonic in time depended on the alpha parameter. It is further shown that the component of the inertial force in the transverse direction is negligible for α < 0.1, increases quadratically for α < 0.5, and tends asymptotically to the classical result as α → ∞, i.e. in still fluid.

show abstract

“…Among them, Fujarra et al [19], Jauvtis and Williamson [14,20]; Flemming and Williamson [21]; Dahl et al [22]; Leong and Wei [23], and Marzouk [24] should be mentioned.…”

Section: Introductionmentioning

confidence: 96%

Experimental Comparison of Two Degrees-of-Freedom Vortex-Induced Vibration on High and Low Aspect Ratio Cylinders with Small Mass Ratio

Gonçalves¹,

Rosetti²,

Fujarra

et al. 2012

Journal of Vibration and Acoustics

View full text Add to dashboard Cite

Vortex-induced motion (VIM) is a specific way for naming the vortex-induced vibration (VIV) acting on floating units. The VIM phenomenon can occur in monocolumn production, storage and offloading system (MPSO) and spar platforms, structures presenting aspect ratio lower than 4 and unity mass ratio, i.e., structural mass equal to the displaced fluid mass. These platforms can experience motion amplitudes of approximately their characteristic diameters, and therefore, the fatigue life of mooring lines and risers can be greatly affected. Two degrees-of-freedom VIV model tests based on cylinders with low aspect ratio and small mass ratio have been carried out at the recirculating water channel facility available at NDF-EPUSP in order to better understand this hydro-elastic phenomenon. The tests have considered three circular cylinders of mass ratio equal to one and different aspect ratios, respectively L/D ¼ 1.0, 1.7, and 2.0, as well as a fourth cylinder of mass ratio equal to 2.62 and aspect ratio of 2.0. The Reynolds number covered the range from 10 000 to 50 000, corresponding to reduced velocities from 1 to approximately 12. The results of amplitude and frequency in the transverse and in-line directions were analyzed by means of the Hilbert-Huang transform method (HHT) and then compared to those obtained from works found in the literature. The comparisons have shown similar maxima amplitudes for all aspect ratios and small mass ratio, featuring a decrease as the aspect ratio decreases. Moreover, some changes in the Strouhal number have been indirectly observed as a consequence of the decrease in the aspect ratio. In conclusion, it is shown that comparing results of small-scale platforms with those from bare cylinders, all of them presenting low aspect ratio and small mass ratio, the laboratory experiments may well be used in practical investigation, including those concerning the VIM phenomenon acting on platforms.

show abstract

Two-degree-of-freedom vortex-induced vibration of a pivoted cylinder below critical mass ratio

Cited by 20 publications

References 30 publications

Experimental study of vortex-induced vibration for drilling risers under uniform flow current

Experimental study of vortex-induced vibration for drilling risers under uniform flow current

Added mass of a circular cylinder oscillating in a free stream

Experimental Comparison of Two Degrees-of-Freedom Vortex-Induced Vibration on High and Low Aspect Ratio Cylinders with Small Mass Ratio

Contact Info

Product

Resources

About