Combined FIV and VIV Effects on a Cantilevered Pipe Discharging Fluid in Deep Waters

2015 ◽  
Author(s):  
Shuai Meng ◽  
Hiroyuki Kajiwara ◽  
Narakorn Srinil
Keyword(s):  
Carbon Capture ◽  
Experimental Studies ◽  
Carbon Capture And Storage ◽  
Cross Flow ◽  
Integration Scheme ◽  
Flow Induced Vibration ◽  
Drag Forces ◽  
Deep Waters ◽  
Cantilevered Pipe ◽  
Wake Oscillators

To avoid or mitigate global warming, several ocean carbon capture and storage concepts have been proposed. One of the recent approaches is to dispose carbon dioxide via a fixed vertical cantilevered pipe onto the seabed in deep waters. Due to a high aspect ratio and flexibility of such long pipe conveying fluid with fixed-free end conditions and external hydrodynamic loading caused by currents, the pipe may experience large-amplitude 3-D vibrations leading to structural failure. Hence, it is essential to understand and investigate the pipe nonlinear dynamic behaviors subject to combined flow-induced vibration (FIV) and vortex-induced vibration (VIV). In this study, the 3-D nonlinear equations of a cantilevered pipe discharging fluid in the sea are analyzed using a Galerkin-based multi modal approach combined with a finite difference Houbolt’s integration scheme. Particular attention is paid to the combined effects of FIV and VIV on the dynamic response of the cantilevered pipe in water. To model the fluctuating lift and drag forces associated with VIV, the two dimensional wake oscillators distributed along the pipe are adopted. Numerical simulations in the FIV case of a pipe discharging fluid in the air are first validated with experimental results in the literature to justify the mathematical models and numerical approaches. Modal convergence analysis is also performed. Results in the combined FIV and VIV cases are then highlighted in order to show the effects of cross-flow and in-line VIV when compared with the pure FIV case. The effects of geometric nonlinearities, the coupling/interaction of multi modes and the space-time modifications of pipe responses and trajectories are highlighted. It is hoped that the numerical observations and findings obtained from this study could be verified by experimental studies which are presently lacking in the literature.

Behaviour of Releases of Carbon Dioxide From Pipelines and Vents

2014 ◽  
Author(s):  
Dan Allason ◽  
Keith Armstrong ◽  
Julian Barnett ◽  
Phil Cleaver ◽  
Ann Halford
Keyword(s):  
Carbon Dioxide ◽  
Carbon Capture ◽  
Dynamic Models ◽  
Fluid Dynamic ◽  
Experimental Studies ◽  
Carbon Capture And Storage ◽  
Research Programme ◽  
The European Union ◽  
High Concentrations ◽  
Carbon Dioxide Co2

A large Research and Development programme has been executed by National Grid to determine the feasibility of transporting carbon dioxide (CO2) by pipeline. Such pipelines would be required to form a transportation system to take the CO2 from its place of capture at an emitter’s site to a place of safe storage within a Carbon Capture and Storage (CCS) scheme. This programme received financial support from the European Union. As part of this programme, National Grid commissioned a series of experimental studies to investigate the behaviour of releases of CO2 mixtures in the gaseous and the liquid (or dense) phase. This has included simulating accidental releases in the form of punctures or ruptures of a buried pipeline and deliberate releases through different venting arrangements. This work is required, as CO2 has the potential to cause some harm to people if they are exposed to it for long enough at high concentrations. This paper gives an overview of the findings from this work and shows how the data has been used to help develop a number of the more pragmatic, predictive models for outflow and dispersion. This work complements the more theoretical studies carried out using state of the art advanced computational fluid dynamic models, employed by other UK based participants (University College London, University of Leeds, Kingston University and the University of Warwick) in the research programme.

Numerical Prediction of 3-D Vortex-Induced Vibration of Catenary Riser In Planar and Non-Planar Flows

2021 ◽  
Author(s):  
Bowen Ma ◽  
Narakorn Srinil
Keyword(s):  
Flow Direction ◽  
Cross Flow ◽  
Travelling Wave ◽  
Flow Angle ◽  
Fluid Structure ◽  
Vortex Induced Vibration ◽  
Drag Forces ◽  
Wake Oscillators ◽  
Lift And Drag ◽  
Planar Flows

Abstract Vortex-induced vibration (VIV) is one of the most critical issues in deepwater developments due to its resultant fatigue damage to subsea structures such as risers, pipelines and jumpers. Although VIV effects on slender bodies have been comprehensively studied over decades, very few studies have dealt with VIV modelling and prediction of catenary risers in current flows with varying directions leading to complex fluid-structure interactions. This study advances a numerical model to simulate and predict 3-D VIV responses of a catenary riser in three flow orientations, relative to the riser curvature plane, including concave/convex (planar) and perpendicular (non-planar) flows. The model is described by equations of cross-flow and in-line responses of the catenary riser coupled with the hydrodynamic forces modelled by the distributed nonlinear wake oscillators. A finite difference method is applied to solve the coupled fluid-structure dynamic system. To consider the approaching flow in different directions, the vortex-induced lift and drag forces are formulated by accounting for the effect of flow angle of attack and the riser-flow relative velocities. Results show VIV features of a long catenary riser exhibiting a standing and travelling wave response pattern. VIV response amplitudes and oscillation frequencies are predicted and compared with experimental results in the literature for both straight and catenary risers. Overall results highlight the model capability in capturing the effect of approaching flow direction on 3-D VIV of the curved inclined flexible riser.

GASDECOM: Carbon Dioxide and Other Components

2010 ◽  
Author(s):  
Andrew Cosham ◽  
Robert J. Eiber ◽  
Edward B. Clark
Keyword(s):  
Carbon Dioxide ◽  
Phase Diagram ◽  
Phase Boundary ◽  
Carbon Capture ◽  
Experimental Studies ◽  
Carbon Capture And Storage ◽  
Vapour Phase ◽  
Successful Implementation ◽  
And Storage ◽  
Arrest Toughness

Carbon dioxide (CO2) pipelines are more susceptible to long running fractures than hydrocarbon gas pipelines because of the decompression characteristics of CO2. The key to understanding this issue is the phase diagram and the liquid-vapour phase boundary. GASDECOM — based on the BWRS equation of state — is a program widely used for calculating the decompression behaviour of mixtures of hydrocarbons. The calculated decompression wave velocity curve is then used in models such as the Battelle Two Curve Model to determine the toughness required to arrest a propagating ductile fracture. GASDECOM is capable of modelling mixtures of hydrocarbons (methane through to hexane), nitrogen and carbon dioxide. It therefore can (and has) been used to investigate the effect of methane and nitrogen on the decompression characteristics of CO2. Pipelines can be expected to play a significant role in the transportation infrastructure required for the successful implementation of carbon capture and storage (CCS). The composition of the carbon dioxide rich stream to be transported in a pipeline depends on the capture technology, e.g. post-combustion, pre-combustion and oxy-fuel. Post-combustion tends to result in an almost pure stream. The other capture technologies produce a less pure stream, containing potentially significant proportions of other components such as hydrogen, nitrogen, oxygen, argon and methane. One of the factors that will constrain the design and operation of a carbon dioxide pipeline is the effect of these other components on the decompression characteristics, and hence the arrest toughness (amongst other issues). Components such as hydrogen, oxygen and argon cannot currently be considered using GASDECOM. Through a study of the underlying algorithms implemented in GASDECOM, it is shown how GASDECOM can be modified to include these additional components relevant to carbon capture and storage. The effect of impurities such as hydrogen on the decompression characteristics is then illustrated, and related back to their effect on the phase diagram and the liquid-vapour phase boundary. The sensitivity of the results to the use of equations of state other than BWRS is also illustrated. Simplifications that follow from the decompression behaviour of carbon dioxide are also highlighted. Finally, the small and large scale experimental studies that are required to validate predictions of the decompression behaviour and the arrest toughness are discussed.

Vibration Excitation Force Measurements in a Rotated Triangular Tube Bundle Subjected to Two-Phase Cross Flow

2005 ◽  
Author(s):  
C. Zhang ◽  
M. J. Pettigrew ◽  
N. W. Mureithi
Keyword(s):  
Tube Bundle ◽  
Cross Flow ◽  
Fretting Wear ◽  
Experimental Program ◽  
Force Measurements ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Drag Forces ◽  
Vibration Excitation ◽  
Excitation Force

Two-phase cross flow exists in many shell-and-tube heat exchangers. Flow-induced vibration excitation forces can cause tube motion that will result in long-term fretting-wear or fatigue. Detailed vibration excitation force measurements in tube bundles subjected to two-phase cross flow are required to understand the underlying vibration excitation mechanisms. An experimental program was undertaken with a rotated-triangular array of cylinders subjected to air/water flow to simulate two-phase mixtures over a broad range of void fraction and mass fluxes. Both the dynamic lift and drag forces were measured with strain gage instrumented cylinders. The experiments revealed somewhat unexpected but significant quasi-periodic forces in both the drag and lift directions. The periodic forces appeared well correlated along the cylinder with the drag force somewhat better correlated than the lift forces. The periodic forces are also dependent on the position of the cylinder within the bundle.

scholarly journals Experimental studies of a single flexibly-mounted rod in a triangular rod bundle in cross-flow

2018 ◽  
Vol 148 ◽  
pp. 09002
Author(s):  
Sabine Upnere ◽  
Normunds Jekabsons ◽  
Sergejs Dementjevs ◽  
Michael Wohlmuther
Keyword(s):  
Experimental Studies ◽  
Cross Flow ◽  
Flow Induced Vibration ◽  
Rod Bundle ◽  
Rod System ◽  
Flow Induced Vibrations ◽  
The Stability ◽  
Paul Scherrer ◽  
Fixed Array ◽  
Rod Array

Experiments on flow-induced vibrations using a closely-packed triangular rod array with a pitch-todiameter ratio of 1.1 in water cross-flow was carried out at Paul Scherrer Institute. The bundle consists of 21 row of five rods in each one. Single flexibly-mounted test rod (TR) is in the fourth row in an otherwise fixed array. The test rod can freely move in the transverse and in-line direction. Two accelerometer sensors were attached at both ends of the TR to measure the rod response on the fluid flow. The effect of flow rate on the stability of the flexibly-mounted TR has been analysed. During experiments, it reveals a set of conditions and tendencies for the flow-induced vibration in the closely-packed multi-rod system.

Characteristics of the Flow-Induced Vibration and Forces With 1- and 2-DOF Vibrations and Limiting Solid-to-Fluid Density Ratios

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Osama A. Marzouk
Keyword(s):  
Density Ratio ◽  
Fluid Motion ◽  
Cross Flow ◽  
Fluid Density ◽  
Flow Induced Vibration ◽  
Drag Forces ◽  
Wide Range ◽  
Low Mass ◽  
Lift And Drag ◽  
Density Ratios

We studied various characteristics of the flow-induced vibration (FIV) of a spring-mounted cylinder, and the fluctuating lift and drag forces exerted on the cylinder due to the periodic changes in the fluid motion and vortex structure. We compared two conditions, which represent the limiting cases for the solid-to-fluid density ratio: the cylinder density is negligible relative to the fluid density, and the fluid density is negligible relative to the cylinder density. For both conditions, we examined the changes in these characteristics over a wide range of nondimensional mass-damping for one degree of freedom (1-DOF, cross-flow) and 2-DOF (cross-flow and in-line) vibration. The four cases exhibit differences (especially at low mass-damping) but also have some similarities in the characteristics of the FIV, induced forces, and energy extraction from the flow. We examined these differences and similarities, the implied errors when the in-line DOF is neglected, and the feasibility of using a single mass-damping parameter to describe the FIV.

scholarly journals Large-Scale Computational Screening of Novel Compounds for Carbon Capture

2014 ◽  
Vol 70 (a1) ◽  
pp. C1538-C1538
Author(s):  
Matthew Dunstan ◽  
Wen Liu ◽  
Shyue Ping Ong ◽  
Anubhav Jain ◽  
Kristin Persson ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Power Plants ◽  
Large Scale ◽  
Waste Heat ◽  
Experimental Studies ◽  
Carbon Capture And Storage ◽  
Kinetic Properties ◽  
Computational Screening ◽  
Energy Penalty ◽  
And Storage

Carbon capture and storage (CCS) applications offer a plausible solution to the urgent need for a carbon neutral energy source from stationary sources, including power plants and industrial processes. The most mature technology for post-combustion capture currently uses a liquid sorbent, amine scrubbing. However, with the existing technology, a large amount of heat is required for the regeneration of the liquid sorbent, which introduces a substantial energy penalty. Operation at higher temperatures could reduce this energy penalty by allowing the integration of waste heat back into the power cycle. New solid absorbents for use at intermediate to high temperatures, such as CaO, have shown promise in pilot plant studies, but are still far from ideal due to their poor capacity retention upon successive cycling. This presentation will describe our studies aimed at rationally selecting and designing materials for carbon capture and storage applications. We use ab initio calculations of oxide materials from the Materials Project database1 in an effort to screen for novel materials with optimal thermodynamic and kinetic properties for CO2 looping applications. From the determination of a material's optimised structure and ground state energy we have then constructed a screening routine for materials within the database based on simulating their carbonation equilibria and phase stability under differing atmospheric concentrations of CO2. A number of promising materials were identified from the screening, and we are currently investigating their properties experimentally, by using a combination of methods (including thermogravimetric analysis, in situ x-ray diffraction and microscopy). In this way we are able to assess the validity of the screening methodology, and use the insights afforded by experimental studies to iteratively improve the entire process.

Development of a Numerical Model to Represent Two-Phase Flow Configurations in a Tube Bundle

2011 ◽  
Author(s):  
Hubert Senez ◽  
Ste´phane E´tienne
Keyword(s):  
Numerical Model ◽  
Tube Bundle ◽  
Cross Flow ◽  
Fretting Wear ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Flow Configuration ◽  
Drag Forces ◽  
Flow Configurations ◽  
Two Bubbles

Two-phase cross-flow exists in many shell-and-tube heat exchangers. Flow-induced vibration excitation forces can cause tube motion that will result in long-term fretting wear or fatigue. Studies on the subject, providing results on turbulence-induced displacement, fluid-elastic instabilities, and flow patterns have already been performed. It has been shown that the flow configuration plays an important role in the vibrations excitation mechanism. Previous studies showed the existence of unexpected quasi-periodic forces acting on a tube bundle subjected to two-phase cross-flow. The present work aims to understand the physical origin of these forces. A simple numerical model was developed to simulate two-phase cross-flow acting on a tube bundle. This model considers a continuous liquid potential flow across a tube bundle, with virtual bubbles being introduced in the flow. Three kinds of forces act on the bubbles: buoyancy forces, drag forces, and impact forces. These forces take place between two bubbles, or between a bubble and a cylinder. Two bubbles may coalesce if they hit each other, and conversely a bubble may split into two bubbles if the shear flow is strong enough. These local considerations on bubbles have global consequences on the flow configuration. Preliminary results show similarities between the numerical flow configuration and the experiments.

Vibration Excitation Force Measurements in a Rotated Triangular Tube Bundle Subjected to Two-Phase Cross Flow

2006 ◽  
Vol 129 (1) ◽  
pp. 21-27 ◽  
Author(s):  
C. Zhang ◽  
M. J. Pettigrew ◽  
N. W. Mureithi
Keyword(s):  
Tube Bundle ◽  
Cross Flow ◽  
Fretting Wear ◽  
Experimental Program ◽  
Force Measurements ◽  
Flow Induced Vibration ◽  
Two Phase ◽  
Drag Forces ◽  
Vibration Excitation ◽  
Excitation Force

Two-phase cross flow exists in many shell-and-tube heat exchangers. Flow-induced vibration excitation forces can cause tube motion that will result in long-term fretting-wear or fatigue. Detailed vibration excitation force measurements in tube bundles subjected to two-phase cross flow are required to understand the underlying vibration excitation mechanisms. An experimental program was undertaken with a rotated-triangular array of cylinders subjected to air/water flow to simulate two-phase mixtures over a broad range of void fraction and mass fluxes. Both the dynamic lift and drag forces were measured with strain gage instrumented cylinders. The experiments revealed somewhat unexpected but significant quasi-periodic forces in both the drag and lift directions. The periodic forces appeared well correlated along the cylinder with the drag force somewhat better correlated than the lift forces. The periodic forces are also dependent on the position of the cylinder within the bundle.

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