Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method
A stabilized Higher-Order Boundary Element Method (HOBEM) based on cubic shape functions is presented to solve the linear wave-structure interaction with the presence of steady or slowly varying velocities. The mterms which involves second derivatives of local steady flow are difficult to calculate...
Published in: | Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics |
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American Society of Mechanical Engineers
2018
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Online Access: | https://orbit.dtu.dk/en/publications/cfe506a5-9364-419d-8319-6caa51ab4b72 https://doi.org/10.1115/OMAE2018-78350 |
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ftdtupubl:oai:pure.atira.dk:publications/cfe506a5-9364-419d-8319-6caa51ab4b72 2023-11-05T03:37:48+01:00 Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method Shao, Yan-Lin 2018 https://orbit.dtu.dk/en/publications/cfe506a5-9364-419d-8319-6caa51ab4b72 https://doi.org/10.1115/OMAE2018-78350 eng eng American Society of Mechanical Engineers info:eu-repo/semantics/closedAccess Shao , Y-L 2018 , Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method . in Proceedings of the 37th International Conference on Ocean, Offshore and Arctic Engineering (OMAE2018) : Offshore Technology . vol. 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics , OMAE2018-78350 , American Society of Mechanical Engineers , 37th International Conference on Ocean, Offshore and Artic Engineering (OMAE2018) , Madrid , Spain , 17/06/2018 . https://doi.org/10.1115/OMAE2018-78350 contributionToPeriodical 2018 ftdtupubl https://doi.org/10.1115/OMAE2018-78350 2023-10-11T23:00:12Z A stabilized Higher-Order Boundary Element Method (HOBEM) based on cubic shape functions is presented to solve the linear wave-structure interaction with the presence of steady or slowly varying velocities. The mterms which involves second derivatives of local steady flow are difficult to calculate accurately on structure surfaces with high curvatures. They are also not integrable at the sharp corners. A formulation of the Boundary Value Problem (BVP) in a body-fixed coordinate system is thus adopted, which avoids the calculation of the m-terms. The use of body-fixed coordinate system also avoid the inconsistency in the traditional perturbation method when 2nd order slowly-vary motions are larger than the linear motions. The stabilized numerical method presented in this paper is based on streamline integration and biased differencing scheme along the streamlines. The presence of convective terms in the kinematic and dynamic free surface conditions will lead to instable solution if the explicit method is used. Thus a fully implicit scheme is used in this paper for the time integration of kinematic and dynamic free surface conditions. In an implicit scheme, solution of an additional matrix equation is normally required due to the fact that the presence of convective terms are approximated using the variables at current time step rather than the previous time steps only. A method that avoids solving such matrix equation is presented in this paper, which will reduce the computational efforts in the implicit method. The methodology is applicable on unstructured meshes. It can also be used in general second order wave-structure interaction analysis with presence of steady or slowly varying velocities. Article in Journal/Newspaper Arctic Technical University of Denmark: DTU Orbit Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
description |
A stabilized Higher-Order Boundary Element Method (HOBEM) based on cubic shape functions is presented to solve the linear wave-structure interaction with the presence of steady or slowly varying velocities. The mterms which involves second derivatives of local steady flow are difficult to calculate accurately on structure surfaces with high curvatures. They are also not integrable at the sharp corners. A formulation of the Boundary Value Problem (BVP) in a body-fixed coordinate system is thus adopted, which avoids the calculation of the m-terms. The use of body-fixed coordinate system also avoid the inconsistency in the traditional perturbation method when 2nd order slowly-vary motions are larger than the linear motions. The stabilized numerical method presented in this paper is based on streamline integration and biased differencing scheme along the streamlines. The presence of convective terms in the kinematic and dynamic free surface conditions will lead to instable solution if the explicit method is used. Thus a fully implicit scheme is used in this paper for the time integration of kinematic and dynamic free surface conditions. In an implicit scheme, solution of an additional matrix equation is normally required due to the fact that the presence of convective terms are approximated using the variables at current time step rather than the previous time steps only. A method that avoids solving such matrix equation is presented in this paper, which will reduce the computational efforts in the implicit method. The methodology is applicable on unstructured meshes. It can also be used in general second order wave-structure interaction analysis with presence of steady or slowly varying velocities. |
format |
Article in Journal/Newspaper |
author |
Shao, Yan-Lin |
spellingShingle |
Shao, Yan-Lin Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method |
author_facet |
Shao, Yan-Lin |
author_sort |
Shao, Yan-Lin |
title |
Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method |
title_short |
Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method |
title_full |
Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method |
title_fullStr |
Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method |
title_full_unstemmed |
Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method |
title_sort |
numerical analysis of second-order mean wave forces by a stablized higher order boundary element method |
publisher |
American Society of Mechanical Engineers |
publishDate |
2018 |
url |
https://orbit.dtu.dk/en/publications/cfe506a5-9364-419d-8319-6caa51ab4b72 https://doi.org/10.1115/OMAE2018-78350 |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Shao , Y-L 2018 , Numerical Analysis of Second-Order Mean Wave Forces by a Stablized Higher Order Boundary Element Method . in Proceedings of the 37th International Conference on Ocean, Offshore and Arctic Engineering (OMAE2018) : Offshore Technology . vol. 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics , OMAE2018-78350 , American Society of Mechanical Engineers , 37th International Conference on Ocean, Offshore and Artic Engineering (OMAE2018) , Madrid , Spain , 17/06/2018 . https://doi.org/10.1115/OMAE2018-78350 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1115/OMAE2018-78350 |
container_title |
Volume 9: Offshore Geotechnics; Honoring Symposium for Professor Bernard Molin on Marine and Offshore Hydrodynamics |
_version_ |
1781693505725267968 |