Mode excitation hysteresis of a flexible cylinder undergoing vortex-induced vibrations

Gedikli, Ersegun Deniz; Dahl, Jason

doi:10.1016/j.jfluidstructs.2017.01.006

Cited by 27 publications

(4 citation statements)

References 21 publications

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“…5, which features an intermittent VIV response with an amplitude modulation including three phases: build-up, lock-in, and dryout. 92 The interesting phenomenon of the hysteresis response for the flexible cylinder 42 appeared as well in the unsteady flow, reported in several experiments. 92,95 Such response was especially prominent in the slowly varying flow cases, namely the slowing accelerating or decelerating cases.…”

Section: Figmentioning

confidence: 75%

“…Since Brika et al 34 first conducted laboratory experiments on a flexible cylinder placed in the uniform flow, several other well controlled laboratory experiments 21,[35][36][37][38][39][40][41][42] have been conducted to study the structural responses, fluid forces, and wake patterns of a flexible cylinder in the flow. Additionally, large-scale experiments in both deep water basin facilities and field 19,[43][44][45][46][47][48] helped to shed some light on the response of the slender structure with a very large aspect ratio close to those used in the real ocean.…”

Section: Characters Of the Viv Structural Responsementioning

confidence: 99%

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Flexible cylinder flow-induced vibration

Lin

Fan

et al. 2022

Physics of Fluids

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In this paper, we conducted a selective review on the recent progress in physics insight and modeling of flexible cylinder flow-induced vibrations (FIVs). FIVs of circular cylinders include vortex-induced vibrations (VIVs) and wake-induced vibrations (WIVs), and they have been the center of the fluid-structure interaction (FSI) research in the past several decades due to the rich physics and the engineering significance. First, we summarized the new understanding of the structural response, hydrodynamics, and the impact of key structural properties for both the isolated and multiple circular cylinders. The complex FSI phenomena observed in experiments and numerical simulations are explained carefully via the analysis of the vortical wake topology. Following up with several critical future questions to address, we discussed the advancement of the artificial intelligent and machine learning (AI/ML) techniques in improving both the understanding and modeling of flexible cylinder FIVs. Though in the early stages, several AL/ML techniques have shown success, including auto-identification of key VIV features, physics-informed neural network in solving inverse problems, Gaussian process regression for automatic and adaptive VIV experiments, and multi-fidelity modeling in improving the prediction accuracy and quantifying the prediction uncertainties. These preliminary yet promising results have demonstrated both the opportunities and challenges for understanding and modeling of flexible cylinder FIVs in today's big data era.

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Section: Figmentioning

confidence: 75%

Section: Characters Of the Viv Structural Responsementioning

confidence: 99%

Flexible cylinder flow-induced vibration

Lin

Fan

et al. 2022

Physics of Fluids

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“…For example, when predicting the VIV response of a long, slender marine riser in the ocean current using the hydrodynamic coefficients acquired from the rigid cylinder forced vibration experiment, a method of searching data tables contained in databases and using parametric interpolation is currently used (40). The use of deep learning methods allows the application of effective optimization methods, expanding the parametric space to represent appropriate riser physical conditions and enabling the study of complex phenomena, such as the recently observed flexible cylinder VIV hysteretic response associated with mode switch (42) or extremely large vibrations observed in some experiments (43).…”

Section: Discussionmentioning

confidence: 99%

A robotic Intelligent Towing Tank for learning complex fluid-structure dynamics

et al. 2019

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We describe the development of the Intelligent Towing Tank, an automated experimental facility guided by active learning to conduct a sequence of vortex-induced vibration (VIV) experiments, wherein the parameters of each next experiment are selected by minimizing suitable acquisition functions of quantified uncertainties. This constitutes a potential paradigm shift in conducting experimental research, where robots, computers, and humans collaborate to accelerate discovery and to search expeditiously and effectively large parametric spaces that are impracticable with the traditional approach of sequential hypothesis testing and subsequent train-and-error execution. We describe how our research parallels efforts in other fields, providing an orders-of-magnitude reduction in the number of experiments required to explore and map the complex hydrodynamic mechanisms governing the fluid-elastic instabilities and resulting nonlinear VIV responses. We show the effectiveness of the methodology of “explore-and-exploit” in parametric spaces of high dimensions, which are intractable with traditional approaches of systematic parametric variation in experimentation. We envision that this active learning approach to experimental research can be used across disciplines and potentially lead to physical insights and a new generation of models in multi-input/multi-output nonlinear systems.

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“…Owing to the cyclicity and asymmetry of vortex shedding, the fluid will exert a cyclic pulsating force to the structure in both in-line and cross-flow directions, causing it to vibrate in both directions. This is what we call vortex-induced vibrations (VIV) [1,2]. When the natural frequency of the riser structure is close to the vortex shedding frequency, vibration will force the vortex shedding frequency to lock in somewhere near the natural frequency of the structure, referred to as a ”lock-in”, thereby intensifying the cross-flow vibration of the riser.…”

Section: Introductionmentioning

confidence: 99%

Investigation on Vortex-Induced Vibration Experiment of a Standing Variable-Tension Deepsea Riser Based on BFBG Sensor Technology

Cong

Dong

et al. 2019

Sensors

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A vortex-induced vibration (VIV) experiment on a standing variable-tension deepsea riser was conducted to investigate the applicability and sensitivity of Bare Fiber Bragg Grating (BFBG) sensor technology for testing deepsea riser vibrations. The dominant frequencies, dimensionless displacements, in-line and cross-flow couplings of the riser VIV under different top tensions were observed through wavelet transform and modal decomposition. The result indicated that, excited by the same external flow velocities, the cross-flow and in-line dominant frequencies of the riser both decreased with increasing top tension. In terms of displacement responses, increasing top tension caused the root mean square (RMS) displacement to decrease and the vibration amplitude to reduce. In terms of cross-flow and in-line coupling, the closer a location is to the ends of the riser, the smaller the trajectory is and the more standard the “8” becomes. During top tension increases, there exists a “lag” in the time when the riser’s vibration trajectory becomes an “8”. The Slalom Surround Installation approach can effectively prevent the local breakage of the optical fiber string. BFBG sensor technology can give an accurate presentation of the displacement time history, vibration amplitude and frequency of the riser, provides a clear picture of how the riser’s mode and VIV evolve as a function of flow velocity.

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Mode excitation hysteresis of a flexible cylinder undergoing vortex-induced vibrations

Cited by 27 publications

References 21 publications

Flexible cylinder flow-induced vibration

Flexible cylinder flow-induced vibration

A robotic Intelligent Towing Tank for learning complex fluid-structure dynamics

Investigation on Vortex-Induced Vibration Experiment of a Standing Variable-Tension Deepsea Riser Based on BFBG Sensor Technology

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