On the stability of a free-to-rotate short-tail fairing and a splitter plate as suppressors of vortex-induced vibration

Assi, Gustavo R. S.; Bearman, P. W.; Tognarelli, Michael A.

doi:10.1016/j.oceaneng.2014.10.007

Cited by 80 publications

(20 citation statements)

References 15 publications

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“…The affiliation devices attached to the bluff bodies presented above, including fairing and splitter plates, have been experimentally and numerically proved to be effective passive VIV suppression devices. However, recent studies show that such two devices sometime fail to suppress the vibration, and instead, they may result in more serious galloping responses with large or even uncontrollable amplitudes due to their asymmetrical geometries relative to the incoming flow direction [154,[170][171][172][173][174] .…”

Section: Galloping Of Circular Cylinder With Attached Structuresmentioning

confidence: 99%

A review on flow-induced vibration of offshore circular cylinders

2020

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As a fundamental fluid-structure interaction (FSI) phenomenon, vortex-induced vibrations (VIVs) of circular cylinders have been the center of the FSI research in the past several decades. Apart from its scientific significance in rich physics, VIVs are paid great attentions by offshore engineers, as they are encountered in many ocean engineering applications. Recently, with the development of research and application, wake-induced vibration (WIV) for multiple cylinders and galloping for VIV suppression attachments are attracting a growing research interest. All these phenomena are connected with the flow-induced vibration (FIV). In this paper, we review and give some discussions on the FIV of offshore circular cylinders, including the research progress on the basic VIV mechanism of an isolated rigid or flexible cylinder, interference of multiple cylinders concerning WIV of multiple cylinders, practical VIV suppression and unwanted galloping for cylinder of attachments. Finally, we draw concluding remarks, give some comments and propose future research prospects, especially on the major challenges as well as potentials in the offline/online modelling and prediction of real-scale offshore structures with high-fidelity CFD methods, new experimental facilities and applications of artificial intelligence tools.

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Section: Galloping Of Circular Cylinder With Attached Structuresmentioning

confidence: 99%

A review on flow-induced vibration of offshore circular cylinders

2020

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“…Other related numerical simulation parameters are ( = 0.5, natural frequency of the plate), ℎ (ℎ = 0.002 m, height of the plate), and 2 = 1599 (N × s/m) (as can be seen from (1)). Equations (6), (7), (8), and (14) show that when we change the plate length, the total moment of inertia of the plate also changes with (6), (7), and (8). The spring stiffness of the plate changes with the total moment of inertia of the plate is also obtained by (14).…”

Section: Numerical Simulation Conditionsmentioning

confidence: 99%

“…The results show that these devices can effectively reduce the resistance and suppress vortex vibration. Assi et al [8] have mainly studied the stability of a free-to-rotate short-tail fairing and a splitter plate as suppressors of vortex-induced vibration. They studied the rotating (free-to-rotate suppressors in 2-dof) and nonrotating (fixed suppressors in 1-dof) at different reduced speed.…”

Section: Introductionmentioning

confidence: 99%

Structure Optimization of a Vibration Suppression Device for Underwater Moored Platforms Using CFD and Neural Network

Mao

Zhao

2017

Complexity

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We only consider the underwater mooring platform (UMP) and the plate moving in the transverse direction, and the plate can be relative to the UMP free rotation. In the case of constant flow rate ( = 1 m/s), the effect of different dimensionless plate length ( / ) and damping value ( ) on the UMP was studied. We get the sample data point set by computational fluid dynamics (CFD) simulation with changing the dimensionless plate length ( / = 0.3, 0.5, 0.75, 1.0, 1.25, 1.5) and damping value ( = 50, 75, 100, 125, 175, 250, 300 (N × s/m)). The optimal value of the vibration suppression rate is obtained by backpropagation (BP) neural network and genetic algorithm. The optimal vibration suppression rate is = 0.9878 and the corresponding variable value is / = 1.0342, = 57.9631 (N × s/m). In order to verify the accuracy of the optimization, we perform the CFD numerical simulation with the optimized parameters and compare the theoretical optimization results with the CFD simulation result. The absolute error between CFD simulation and optimal is only 0.0037. Finally, we compare the results of CFD simulation based on optimal parameter with the bare UMP and analyze their dimensionless amplitude, wake structure, and lift coefficient. It is shown that BP neural network and generic algorithm are effective.

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“…The passive devices using streamlining principle like fairings and splitter plates have great demand in industries [5]- [7], however, they are only unidirectional to the flow. Some of the devices are flexible, but this passive device depends on maintenance and their ability to align with the flow [7]- [9]. Lou et.…”

Section: Introductionmentioning

confidence: 99%

Effect of Shroud Hole on the Force Characteristics of a Circular Cylinder

Osrin*,

Azmi*,

Yusoff

et al. 2019

IJEAT

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Characteristics of flow pass a shrouded cylinder were investigated experimentally using uniform and non-uniform hole shrouds. The experiments were performed to compare the effect of hole-uniformity of the perforated shroud on the cylinder lift and drag. The porosity for uniform hole shrouds in triangular and square configurations were set around 0.30, while that for non-uniform hole shrouds were set from 0.25 to 0.37. The diameter ratio between the shroud and the bare cylinder was set at 2.0. The experiment was performed in a wind tunnel at Reynolds Number of 9.345 x 103 based on the bare cylinder diameter and constant incoming air flow speed. Results showed that although all shrouded cylinder models reduced drag significantly in comparison to that of the bare cylinder case, the non-uniform hole shrouds were considerably effective than the uniform hole shrouds. Total drag reduction achieved by the non-uniform hole shrouds of 30% porosity was between 90-95% whereas that of uniform hole was only 55-80% at the same porosity.

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On the stability of a free-to-rotate short-tail fairing and a splitter plate as suppressors of vortex-induced vibration

Cited by 80 publications

References 15 publications

A review on flow-induced vibration of offshore circular cylinders

A review on flow-induced vibration of offshore circular cylinders

Structure Optimization of a Vibration Suppression Device for Underwater Moored Platforms Using CFD and Neural Network

Effect of Shroud Hole on the Force Characteristics of a Circular Cylinder

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