Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D
Steep, focusing waves can experience fast and local nonlinear evolution of the spectrum due to wave-wave interactions resulting in energy transfer to both higher and lower wavenumber components. The shape and kinematics of a steep wave may, thus, differ substantially from the predictions of linear t...
| Main Authors: | , , |
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| Format: | Conference item |
| Language: | English |
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American Society of Mechanical Engineers
2019
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| _version_ | 1797100897129463808 |
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| author | Barratt, D Bingham, H Adcock, T |
| author_facet | Barratt, D Bingham, H Adcock, T |
| author_sort | Barratt, D |
| collection | OXFORD |
| description | Steep, focusing waves can experience fast and local nonlinear evolution of the spectrum due to wave-wave interactions resulting in energy transfer to both higher and lower wavenumber components. The shape and kinematics of a steep wave may, thus, differ substantially from the predictions of linear theory. We have investigated the role of nonlinear interactions on group-shape for a steep, narrow-banded, directionally-spread wave group focusing in deep water using the fully-nonlinear potential flow solver, OceanWave3D. Exact second-order correction of the initial conditions has been implemented together with a novel third-order approximate correction based on a Stokestype formulation for surface elevation combined with a scalingargument for the third-order velocity potential. Four-phase separation reveals that the third-order scheme provides a good estimate for the third-order superharmonics. A quantitative assessment of numerical error has also been performed for the spatial and temporal discretization, including energy conservation, a reversibility check and validation against previous simulations performed with a higher-order spectral (HOS) code. The initially narrow-banded amplitude spectrum exhibits the formation of sidelobes at angles of approximately ±35° to the spectral peak during the simulated extreme wave event, occurring in approximately 10 wave periods, with a preferential energy transfer to high-wavenumber components. The directional energy transfer is attributed to resonant third-order interactions with a discussion of the engineering implications. |
| first_indexed | 2024-03-07T05:44:12Z |
| format | Conference item |
| id | oxford-uuid:e6a15280-bd50-48b6-8b38-8e246e73afbb |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T05:44:12Z |
| publishDate | 2019 |
| publisher | American Society of Mechanical Engineers |
| record_format | dspace |
| spelling | oxford-uuid:e6a15280-bd50-48b6-8b38-8e246e73afbb2022-03-27T10:32:38ZNonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3DConference itemhttp://purl.org/coar/resource_type/c_5794uuid:e6a15280-bd50-48b6-8b38-8e246e73afbbEnglishSymplectic Elements at OxfordAmerican Society of Mechanical Engineers2019Barratt, DBingham, HAdcock, TSteep, focusing waves can experience fast and local nonlinear evolution of the spectrum due to wave-wave interactions resulting in energy transfer to both higher and lower wavenumber components. The shape and kinematics of a steep wave may, thus, differ substantially from the predictions of linear theory. We have investigated the role of nonlinear interactions on group-shape for a steep, narrow-banded, directionally-spread wave group focusing in deep water using the fully-nonlinear potential flow solver, OceanWave3D. Exact second-order correction of the initial conditions has been implemented together with a novel third-order approximate correction based on a Stokestype formulation for surface elevation combined with a scalingargument for the third-order velocity potential. Four-phase separation reveals that the third-order scheme provides a good estimate for the third-order superharmonics. A quantitative assessment of numerical error has also been performed for the spatial and temporal discretization, including energy conservation, a reversibility check and validation against previous simulations performed with a higher-order spectral (HOS) code. The initially narrow-banded amplitude spectrum exhibits the formation of sidelobes at angles of approximately ±35° to the spectral peak during the simulated extreme wave event, occurring in approximately 10 wave periods, with a preferential energy transfer to high-wavenumber components. The directional energy transfer is attributed to resonant third-order interactions with a discussion of the engineering implications. |
| spellingShingle | Barratt, D Bingham, H Adcock, T Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D |
| title | Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D |
| title_full | Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D |
| title_fullStr | Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D |
| title_full_unstemmed | Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D |
| title_short | Nonlinear evolution of a steep, focusing wave group in deep water simulated with OceanWave3D |
| title_sort | nonlinear evolution of a steep focusing wave group in deep water simulated with oceanwave3d |
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