Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model
This is the author accepted manuscript. The final version is available from ASME via the DOI in this record Underwater dynamic power cables connected to offshore floating energy devices are subject to ocean flow turbulence and, through eddy shedding, may experience vortex-induced vibration (VIV). A...
Published in: | Volume 7: CFD & FSI |
---|---|
Main Authors: | , , , , , , |
Format: | Conference Object |
Language: | English |
Published: |
American Society of Mechanical Engineers (ASME)
2023
|
Subjects: | |
Online Access: | http://hdl.handle.net/10871/134636 https://doi.org/10.1115/omae2023-105249 |
id |
ftunivexeter:oai:ore.exeter.ac.uk:10871/134636 |
---|---|
record_format |
openpolar |
spelling |
ftunivexeter:oai:ore.exeter.ac.uk:10871/134636 2023-12-31T10:01:54+01:00 Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model Badhurshah, R Srinil, N Chaplin, JR Thies, P Johanning, L Borthwick, AGL Venugopal, V 2023 http://hdl.handle.net/10871/134636 https://doi.org/10.1115/omae2023-105249 en eng American Society of Mechanical Engineers (ASME) Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, 7 orcid:0000-0003-3431-8423 (Thies, Philipp) ScopusID: 55134959500 (Thies, Philipp) ResearcherID: H-2490-2011 (Thies, Philipp) orcid:0000-0002-3792-3373 (Johanning, Lars) ScopusID: 13605483700 (Johanning, Lars) ASME 2023: 42nd International Conference on Ocean, Offshore and Arctic Engineering, 11–16 June 2023, Melbourne, Australia. Paper No: OMAE2023-105249 https://doi.org/10.1115/omae2023-105249 EP/W015102/1 http://hdl.handle.net/10871/134636 9780791886892 © 2023 ASME. This version is made available under the CC-BY 4.0 license: https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ Conference paper 2023 ftunivexeter https://doi.org/10.1115/omae2023-105249 2023-12-01T00:05:02Z This is the author accepted manuscript. The final version is available from ASME via the DOI in this record Underwater dynamic power cables connected to offshore floating energy devices are subject to ocean flow turbulence and, through eddy shedding, may experience vortex-induced vibration (VIV). A high level of turbulence intensity may cause fatigue damage to cables during the operation. The present preliminary study investigates the VIV response of a rigid circular cylinder in free-stream turbulence. A phenomenological reduced-order wake oscillator model is coupled with a stochastic differential equation that represents flow turbulence. The model consists of two coupled ordinary differential equations: a structure oscillator forced by the wake vortex shedding and a van der Pol oscillator coupled with the structural acceleration. Wake oscillator models have been extensively used in the past, with several application-specific versions having been developed. The stochastic differential equation accounts for random fluctuations in the fluid flow velocity. Here, we vary the turbulence intensity in the model up to a maximum of 20%. The cylinder response is not significantly affected by very low levels of turbulence, but amplitude modulations and beating phenomena are observed in a strongly turbulent flow. Lock-in, whereby the structure oscillation frequency synchronizes with the vortex shedding frequency, is also explored to study how the resonant frequencies differ in cases with and without the present turbulence. We also investigate the stochastic VIV response subject to the mass ratio variation. The model validation with selected empirical coefficients of the prediction model is also presented. The findings should be of benefit to researchers and design engineers who are concerned with the development of floating energy systems by better characterizing operational load conditions for new installations. Engineering and Physical Sciences Research Council (EPSRC) Conference Object Arctic University of Exeter: Open Research Exeter (ORE) Volume 7: CFD & FSI |
institution |
Open Polar |
collection |
University of Exeter: Open Research Exeter (ORE) |
op_collection_id |
ftunivexeter |
language |
English |
description |
This is the author accepted manuscript. The final version is available from ASME via the DOI in this record Underwater dynamic power cables connected to offshore floating energy devices are subject to ocean flow turbulence and, through eddy shedding, may experience vortex-induced vibration (VIV). A high level of turbulence intensity may cause fatigue damage to cables during the operation. The present preliminary study investigates the VIV response of a rigid circular cylinder in free-stream turbulence. A phenomenological reduced-order wake oscillator model is coupled with a stochastic differential equation that represents flow turbulence. The model consists of two coupled ordinary differential equations: a structure oscillator forced by the wake vortex shedding and a van der Pol oscillator coupled with the structural acceleration. Wake oscillator models have been extensively used in the past, with several application-specific versions having been developed. The stochastic differential equation accounts for random fluctuations in the fluid flow velocity. Here, we vary the turbulence intensity in the model up to a maximum of 20%. The cylinder response is not significantly affected by very low levels of turbulence, but amplitude modulations and beating phenomena are observed in a strongly turbulent flow. Lock-in, whereby the structure oscillation frequency synchronizes with the vortex shedding frequency, is also explored to study how the resonant frequencies differ in cases with and without the present turbulence. We also investigate the stochastic VIV response subject to the mass ratio variation. The model validation with selected empirical coefficients of the prediction model is also presented. The findings should be of benefit to researchers and design engineers who are concerned with the development of floating energy systems by better characterizing operational load conditions for new installations. Engineering and Physical Sciences Research Council (EPSRC) |
format |
Conference Object |
author |
Badhurshah, R Srinil, N Chaplin, JR Thies, P Johanning, L Borthwick, AGL Venugopal, V |
spellingShingle |
Badhurshah, R Srinil, N Chaplin, JR Thies, P Johanning, L Borthwick, AGL Venugopal, V Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model |
author_facet |
Badhurshah, R Srinil, N Chaplin, JR Thies, P Johanning, L Borthwick, AGL Venugopal, V |
author_sort |
Badhurshah, R |
title |
Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model |
title_short |
Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model |
title_full |
Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model |
title_fullStr |
Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model |
title_full_unstemmed |
Stochastic Vortex-Induced Vibration in Free-Stream Turbulence Using a Phenomenological Model |
title_sort |
stochastic vortex-induced vibration in free-stream turbulence using a phenomenological model |
publisher |
American Society of Mechanical Engineers (ASME) |
publishDate |
2023 |
url |
http://hdl.handle.net/10871/134636 https://doi.org/10.1115/omae2023-105249 |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, 7 orcid:0000-0003-3431-8423 (Thies, Philipp) ScopusID: 55134959500 (Thies, Philipp) ResearcherID: H-2490-2011 (Thies, Philipp) orcid:0000-0002-3792-3373 (Johanning, Lars) ScopusID: 13605483700 (Johanning, Lars) ASME 2023: 42nd International Conference on Ocean, Offshore and Arctic Engineering, 11–16 June 2023, Melbourne, Australia. Paper No: OMAE2023-105249 https://doi.org/10.1115/omae2023-105249 EP/W015102/1 http://hdl.handle.net/10871/134636 9780791886892 |
op_rights |
© 2023 ASME. This version is made available under the CC-BY 4.0 license: https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1115/omae2023-105249 |
container_title |
Volume 7: CFD & FSI |
_version_ |
1786807719560216576 |