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Showing 1 to 20 of 42 for “"VIV"”.
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FSI Methodology for Analyzing VIV on Subsea Pipeline Free Spans with Practical Boundary Conditions
… in performing vortex-induced vibration (VIV) analysis of pipeline free spans is that both ends of the free span are fixed and/or pinned in order to simplify computational simulations; however, Det Norske Veritas (DNV – translation to The Norwegian Truth) Recommended Practice F105 states …
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Investigations on Vortex-induced Vibration (VIV) Phenomena of Single-and-double-cylinder Flexible Beam Arrangements of Energy Harvesters
… cost, the Van der Pol ODE system describing the VIV of cylinder-type harvester is still a feasible and economical method. Mix model coupling the acceleration, velocity and displacement model of structure acting on vortex shedding wake, is a possible way to extend their applicability to finite …
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The influence of high harmonic force on fatigue life and its prediction via coupled inline-crossflow VIV modeling
Vortex Induced Vibrations (VIV) of a flexibly mounted rigid cylinder placed in a flow is a canonical problem of fluid-structure interactions and the study of VIV and the resulting material fatigue is particularly important in design for ultra-deep water oil exploration and development. Long …
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Drag amplification and fatigue damage in vortex-induced vibrations
… 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 damage. Although the last …
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Visualization of vibration experienced in offshore platforms
… the visualization of vortex-induced vibration (VIV) in marine risers. VIV is vibration experienced by marine risers in offshore drilling platforms due to ocean current flows, and appears to be perpendicular to the direction of such flows. VIV causes oil companies large capital losses, supply …
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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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Vortex Induced Vibrations of cylinders : experiments in reducing drag force and amplitude of motion
… 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 formation by …
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Vortex-induced vibration of slender structures in unsteady flow
Vortex-induced vibration (VIV) results in fatigue damage of offshore oil exploration and production structures. In recent years, the offshore industry has begun to employ curved slender structures such as steel catenary risers in deep-water offshore oil systems. The top-end vessel motion causes the …
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Vortex-induced vibration of marine risers : motion and force reconstruction from field and experimental data
Vortex-induced vibration (VIV) of long flexible cylindrical structures enduring ocean currents is ubiquitous in the offshore industry. Though significant effort has gone into understanding this complicated fluid-structure interaction problem, major challenges remain in modeling and predicting the …
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Modelling and analysis of vibrations in flexible cylinders subjected to internal multiphase and external single-phase flows.
… flows and external vortex-induced vibrations (VIV) by taking into account the geometric and hydrodynamic nonlinearities. Flow-induced vibration (FIV) is a common phenomenon observed in various engineering systems such as heat exchangers, nuclear power plants, chemical process plants and …
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Understanding flow-induced vibration via a physics-constrained, data-driven approach
Vortex-induced vibration (VIV) of long flexible cylinders involves a large number of physical variables, such as Strouhal number, Reynolds number, and damping. Due to the nonlinearity and high-dimensionality of the problem, current VIV prediction models have large error bounds, and require …
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Effect of traveling waves on Vortex-Induced Vibration of long flexible cylinders
… are susceptible to Vortex-Induced Vibration (VIV). Accurate prediction of VIV is necessary for estimating the fatigue life as well as for taking corrective measures to prevent the vibrations. State of the art response prediction methods work reasonably well for short flexible cylinders …
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Traveling waves in mode superposition
… 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 Gulf Stream …
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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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A scatter diagram approach to the selection of design currents for prediction of marine riser vortex-induced vibration
… are then used to assess wave forces. To predict VIV fatigue damage the designer needs to know which current profiles have the combined property of long regions of relatively constant velocity and relatively high speed. A sorting algorithm is proposed which searches every current profile for long …
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Vortex-induced vibration of a linearly-sprung cylinder with nonlinear energy sinks
… undergoing rectilinear vortex-induced vibration (VIV) normal to the mean flow. The attachment is a nonlinear energy sink (NES). The essentially nonlinear coupling between the rectilinear motion of the cylinder and the motion of the NES allows for efficient, one-way transfer of kinetic energy from …
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Dynamics of long flexible cylinders at high-mode number in uniform and sheared flows
… In the experiments, Vortex-Induced Vibrations (VIV) happened at one frequency at one time, rather than at many frequencies simultaneously. The single VIV frequency varied with time, but the VIV frequencies did not co-exist. The major impact of time-sharing frequencies is that it increases the …
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Study of reduced order models for vortex-induced vibration and comparison with CFD results
Vortex-induced vibration (VIV) is a dynamic phenomenon that can occur when there is fluid flow past a bluff body with flexibility. Over time, VIV can cause fatigue damage, so it may be desirable to suppress these vibrations. It is important to understand how the system behaves when trying to …
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Deep-sea mining : dewatering plumes, vortex-induced vibrations and economic modelling
… 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 and monitor six dewatering …
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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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