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Showing 1 to 20 of 38 for “"Vortex-induced vibrations"”.
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Vortex-induced vibrations of structural members in natural winds
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1995.
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Drag amplification and fatigue damage in vortex-induced vibrations
… damage and drag force amplification due to Vortex-Induced-Vibrations (VIV) continue to cause significant problems in the design of structures which operate in ocean current environments. These problems are magnified by the uncertainty in VIV prediction, particularly with regard to fatigue …
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Vortex-induced vibrations of a non-linearly supported rigid cylinder
Vortex-Induced Vibrations (VIV) are a complex fluid-structure interaction problem.<br/>VIV are particularly strong for low-mass structures subject to a low damping, as<br/>encountered in the offshore industry, in which structures experiencing VIV can also<br/>be subject to strong structural …
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A study on passive methods of vortex induced vibrations suppression
… in offshore operations, are often affected by vortex-induced vibrations (VIV). This phenomenon is caused by the interaction between a structure and shed vortices which can result in large amplitude vibrations of the structure that may lead to severe damage over time. Repairs to these systems …
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Active/Passive Controls and Energy Harvesting from Vortex-Induced Vibrations
… of using a nonlinear energy sink to control the vortex-induced vibrations of a freely oscillating circular cylinder. It has been postulated that such a system, which consists of a nonlinear spring, can be used to control the motion over a wide range of frequencies. However, introducing an …
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Energy Harvesting from the Vortex-Induced Vibrations of Bluff Body Oscillators
<p>Vortex-induced vibration (VIV) of bluff bodies provides an effective mechanism for harvesting energy from fluid flows. Yet, the complex fluid-structure interactions governing vibration amplitude, synchronization, and energy transfer in single and coupled oscillators remain only partially …
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Rotational movement of a harbor seal whisker during vortex induced vibrations
Harbor seal whiskers have geometry that reduces vortex induced vibrations. Previous experiments with rigid models of the harbor seal whiskers has shown that the reduced vibration of the whisker can be used to detect the wake of other objects in water. This project focused on expanding the …
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Deep-sea mining : dewatering plumes, vortex-induced vibrations and economic modelling
… dewatering plumes, the analysis of the effect of vortex-induced vibrations (VIV) on mining risers, and the development of updated and detailed economic models -which are among the most pressing ones - are addressed in this thesis. PLUMEX field studies were conducted in the Pacific Ocean to create …
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Piezoelectric energy harvesting: vortex induced vibrations in plants, soap films, and arrays of cylinders
… were developed that harvested energy from vortex shedding, both as independent and cooperative devices. The behavior of single devices was studied, but more interestingly, the way that multiple devices arranged together can increase power output was studied. It was shown that individual …
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Numerical and Analytical Analysis of Vortex Induced Vibrations of a Pipeline Close to Seabed
The vortex induced vibrations of a pipeline close to seabed is investigated in this dissertation numerically. Firstly, a novel wake oscillator model is extended from the classic Van der Pol equation by introducing an additional nonlinear term and two empirical coefficients to account explicitly for …
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Vortex Induced Vibrations of cylinders : experiments in reducing drag force and amplitude of motion
Reducing the deleterious effect of Vortex Induced Vibrations (VIV) in marine risers is an important task for ocean engineers; and many competing factors exist in the design of VIV suppression devices. This thesis explores the experimental minimization of the drag force and the disruption of vortex …
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Effects of broad-banded higher harmonics on fatigue damage of risers due to vortex-induced vibrations
Recent works have discussed "chaotic" or "Type-II" riser motion and suggested that it is a general feature of VIV riser response. Chaotic riser response contains broad-banded harmonics and a combination of standing and traveling waves, unlike periodic or " Type-I" motion which contains only …
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Modal interactions and targeted energy transfers in laminar vortex-induced vibrations of a rigid cylinder with strongly nonlinear internal attachments
Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Seth Robbins (robbins.sd@gmail.com) on 2014-01-16T18:19:53Z Item is restricted until 2016-01-16T18:19:34Z
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Traveling waves in mode superposition
Offshore marine risers are subject to Vortex Induced Vibrations (VIV) because of ocean currents. Response prediction techniques which accurately estimate the strain due to VIV are of help in deciding how to mitigate VIV, and also to predict the life of the structure. Experiments conducted in the …
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Design and vibration testing of a flexible seal whisker model
… surface structure that dramatically reduces vortex induced vibrations as they move through the water. Concurrently with rigid whisker experiments, this project focuses on the design and testing of a flexible model. The rubber model was cast with integrated Kevlar strings, for tensioning …
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Velocity characteristics in the wake of an oscillating cylinder
… these downstream velocity properties and the vortex-induced vibrations of the cylinder. In addition to downstream velocities, experimental data include lift and drag forces and cylinder displacement. Vortices are found to be correlated along the entire length of the test cylinder only within a …
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Airfoil Vortex Induced Vibration suppression devices
Vortex Induced Vibrations (VIV) is a major concern of the offshore oil industry. This problem leads to fatigue failure in the marine risers and causes costly replacement of the risers. Appendages such as helical strakes have proven that VIV can be eliminated but at the cost of increased drag. …
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Modeling a piezoelectric flag as a membrane for energy harvesting
… of study. Most notably, energy harvested from vortex-induced vibrations, along with bluff bodies, is of particular interest. After the literature review concerning piezoelectric materials and fluid-based energy harvesting, the system is modeled as a membrane. This modeling requires two coupled …
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Learning hydrodynamic coefficient databases for vortex induced vibration prediction of marine risers using sparse sensor measurements
… technology for flexible cylinder vortex induced vibrations (VIV) predictive modelling. Accurate prediction of the structural response relies heavily on the accuracy of the acquired hydrodynamic coefficient database. Due to the large number of inputs required, the construction of …
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