A 2D Experimental and Numerical Study of Moonpools With Recess
Moonpool resonance is investigated in a two-dimensional setting in terms of regular, forced heave motions of a model with moonpool with different rectangular-shaped recess configurations. A recess is a reduced draft zone in the moonpool. Dedicated experiments were carried out. The model consisted of...
Published in: | Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics |
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ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2587637 2023-05-15T14:24:54+02:00 A 2D Experimental and Numerical Study of Moonpools With Recess Ravinthrakumar, Senthuran Kristiansen, Trygve Ommani, Babak 2018 http://hdl.handle.net/11250/2587637 https://doi.org/10.1115/OMAE2018-78326 eng eng ASME ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering - Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics urn:isbn:978-0-7918-5130-2 http://hdl.handle.net/11250/2587637 https://doi.org/10.1115/OMAE2018-78326 cristin:1613742 Chapter 2018 ftntnutrondheimi https://doi.org/10.1115/OMAE2018-78326 2019-09-17T06:54:36Z Moonpool resonance is investigated in a two-dimensional setting in terms of regular, forced heave motions of a model with moonpool with different rectangular-shaped recess configurations. A recess is a reduced draft zone in the moonpool. Dedicated experiments were carried out. The model consisted of two boxes of 40 cm width each, with a distance of 20 cm between them. Recess configurations varying between 5 cm to 10 cm in length and 5 cm in height were tested. Different drafts were also tested. The free-surface elevation inside the moonpool was measured at eight locations. A large number of forcing periods, and five forcing amplitudes were tested. A time-domain Boundary Element Method (BEM) code based on linear potential flow theory was implemented to investigate the resonance periods, mode shapes as well as the moonpool response as predicted by (linear) potential flow theory. Dominant physical effects were discussed, in particular damping due to flow separation from the sharp corners of the moonpool inlet and recess. The effect of the recess on the piston-mode behavior is discussed. BEM simulations where the effect of flow separation is empirically modelled were also conducted. The non-dimensional moonpool response suggests strong viscous damping at piston-mode resonance. The viscous BEM simulations demonstrate improvement over inviscid BEM, although further improvement of the method is needed. The piston mode shapes are clearly different from the near flat free-surface elevation for a moonpool without recess, consistent with recently published theory. publishedVersion Copyright © 2018 by ASME Book Part Arctic NTNU Open Archive (Norwegian University of Science and Technology) Recess ENVELOPE(-61.516,-61.516,-64.500,-64.500) Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics |
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Open Polar |
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NTNU Open Archive (Norwegian University of Science and Technology) |
op_collection_id |
ftntnutrondheimi |
language |
English |
description |
Moonpool resonance is investigated in a two-dimensional setting in terms of regular, forced heave motions of a model with moonpool with different rectangular-shaped recess configurations. A recess is a reduced draft zone in the moonpool. Dedicated experiments were carried out. The model consisted of two boxes of 40 cm width each, with a distance of 20 cm between them. Recess configurations varying between 5 cm to 10 cm in length and 5 cm in height were tested. Different drafts were also tested. The free-surface elevation inside the moonpool was measured at eight locations. A large number of forcing periods, and five forcing amplitudes were tested. A time-domain Boundary Element Method (BEM) code based on linear potential flow theory was implemented to investigate the resonance periods, mode shapes as well as the moonpool response as predicted by (linear) potential flow theory. Dominant physical effects were discussed, in particular damping due to flow separation from the sharp corners of the moonpool inlet and recess. The effect of the recess on the piston-mode behavior is discussed. BEM simulations where the effect of flow separation is empirically modelled were also conducted. The non-dimensional moonpool response suggests strong viscous damping at piston-mode resonance. The viscous BEM simulations demonstrate improvement over inviscid BEM, although further improvement of the method is needed. The piston mode shapes are clearly different from the near flat free-surface elevation for a moonpool without recess, consistent with recently published theory. publishedVersion Copyright © 2018 by ASME |
format |
Book Part |
author |
Ravinthrakumar, Senthuran Kristiansen, Trygve Ommani, Babak |
spellingShingle |
Ravinthrakumar, Senthuran Kristiansen, Trygve Ommani, Babak A 2D Experimental and Numerical Study of Moonpools With Recess |
author_facet |
Ravinthrakumar, Senthuran Kristiansen, Trygve Ommani, Babak |
author_sort |
Ravinthrakumar, Senthuran |
title |
A 2D Experimental and Numerical Study of Moonpools With Recess |
title_short |
A 2D Experimental and Numerical Study of Moonpools With Recess |
title_full |
A 2D Experimental and Numerical Study of Moonpools With Recess |
title_fullStr |
A 2D Experimental and Numerical Study of Moonpools With Recess |
title_full_unstemmed |
A 2D Experimental and Numerical Study of Moonpools With Recess |
title_sort |
2d experimental and numerical study of moonpools with recess |
publisher |
ASME |
publishDate |
2018 |
url |
http://hdl.handle.net/11250/2587637 https://doi.org/10.1115/OMAE2018-78326 |
long_lat |
ENVELOPE(-61.516,-61.516,-64.500,-64.500) |
geographic |
Recess |
geographic_facet |
Recess |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering - Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics urn:isbn:978-0-7918-5130-2 http://hdl.handle.net/11250/2587637 https://doi.org/10.1115/OMAE2018-78326 cristin:1613742 |
op_doi |
https://doi.org/10.1115/OMAE2018-78326 |
container_title |
Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics |
_version_ |
1766297349326372864 |