Diffraction and instability of short-crested limited-length onedimensional coherent wave trains
Alternative representations of the wave field (as opposed to superposition of Fourier components) are possible. In this paper, behaviour of short-crested limited-length onedimensional coherent wave trains is investigated. Experiments were conducted in the three-dimensional wave tank of the Universit...
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Conference Object |
Language: | unknown |
Published: |
ASME
2015
|
Subjects: | |
Online Access: | http://hdl.handle.net/1959.3/410731 https://doi.org/10.1115/OMAE201541495 |
id |
ftswinburne:tle:5c287e54-21fb-4b28-8a36-6047d8e3f2cd:28f49f06-0da8-44be-9edc-ad1dd0a9c582:1 |
---|---|
record_format |
openpolar |
spelling |
ftswinburne:tle:5c287e54-21fb-4b28-8a36-6047d8e3f2cd:28f49f06-0da8-44be-9edc-ad1dd0a9c582:1 2023-05-15T14:23:53+02:00 Diffraction and instability of short-crested limited-length onedimensional coherent wave trains Babanin, Alexander V. Waseda, Takuji Swinburne University of Technology 2015 http://hdl.handle.net/1959.3/410731 https://doi.org/10.1115/OMAE201541495 unknown ASME http://purl.org/au-research/grants/arc/DP130100227 http://hdl.handle.net/1959.3/410731 https://doi.org/10.1115/OMAE201541495 Copyright © 2015 by ASME. International Conference on Offshore Mechanics and Arctic Engineering: OMAE2015, St. Johns, Canada, 31 May-5 June 2015, Vol. 3 Conference paper 2015 ftswinburne https://doi.org/10.1115/OMAE201541495 2020-03-16T23:26:24Z Alternative representations of the wave field (as opposed to superposition of Fourier components) are possible. In this paper, behaviour of short-crested limited-length onedimensional coherent wave trains is investigated. Experiments were conducted in the three-dimensional wave tank of the University of Tokyo. Description of the directional wave tank and its capacity to generate short-crested coherent wave trains, including those concurrent, superposed and directionallysuperposed is provided. If the crest is shorter than the lateral extent of the wave tank, diffraction tends to redistribute the wave energy into clear surfaces, and thus energy of the wave trains is reduced and the modulational instability bandwidth changes correspondingly. Rates of such nonlinear lateral spread are estimated, and they are proportional to mean wave steepness. To avoid the diffraction, in further tests concurrent trains were mechanically generated, each of which occupied half of the lateral width of the wave tank and had the same energy as another half. The trains had the same frequency, and in order to keep them separate phase shift of 180 degrees was used. Sideband growth was significantly impaired by comparison with the long-crested evolution of the train with the same steepness. Conference Object Arctic Swinburne University of Technology: Swinburne Research Bank |
institution |
Open Polar |
collection |
Swinburne University of Technology: Swinburne Research Bank |
op_collection_id |
ftswinburne |
language |
unknown |
description |
Alternative representations of the wave field (as opposed to superposition of Fourier components) are possible. In this paper, behaviour of short-crested limited-length onedimensional coherent wave trains is investigated. Experiments were conducted in the three-dimensional wave tank of the University of Tokyo. Description of the directional wave tank and its capacity to generate short-crested coherent wave trains, including those concurrent, superposed and directionallysuperposed is provided. If the crest is shorter than the lateral extent of the wave tank, diffraction tends to redistribute the wave energy into clear surfaces, and thus energy of the wave trains is reduced and the modulational instability bandwidth changes correspondingly. Rates of such nonlinear lateral spread are estimated, and they are proportional to mean wave steepness. To avoid the diffraction, in further tests concurrent trains were mechanically generated, each of which occupied half of the lateral width of the wave tank and had the same energy as another half. The trains had the same frequency, and in order to keep them separate phase shift of 180 degrees was used. Sideband growth was significantly impaired by comparison with the long-crested evolution of the train with the same steepness. |
author2 |
Swinburne University of Technology |
format |
Conference Object |
author |
Babanin, Alexander V. Waseda, Takuji |
spellingShingle |
Babanin, Alexander V. Waseda, Takuji Diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
author_facet |
Babanin, Alexander V. Waseda, Takuji |
author_sort |
Babanin, Alexander V. |
title |
Diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
title_short |
Diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
title_full |
Diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
title_fullStr |
Diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
title_full_unstemmed |
Diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
title_sort |
diffraction and instability of short-crested limited-length onedimensional coherent wave trains |
publisher |
ASME |
publishDate |
2015 |
url |
http://hdl.handle.net/1959.3/410731 https://doi.org/10.1115/OMAE201541495 |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
International Conference on Offshore Mechanics and Arctic Engineering: OMAE2015, St. Johns, Canada, 31 May-5 June 2015, Vol. 3 |
op_relation |
http://purl.org/au-research/grants/arc/DP130100227 http://hdl.handle.net/1959.3/410731 https://doi.org/10.1115/OMAE201541495 |
op_rights |
Copyright © 2015 by ASME. |
op_doi |
https://doi.org/10.1115/OMAE201541495 |
_version_ |
1766296347764326400 |