Diffraction method for spar platforms
Abstract This paper presents the numerical hydrodynamic analysis for the motion responses of spar offshore platforms in regular sea waves using both Morison Equation and Diffraction Method. The spar was modeled as a rigid body with three degrees of freedom restrained by mooring lines affecting the...
| Main Authors: | , , |
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| Format: | Conference or Workshop Item |
| Language: | English |
| Published: |
2009
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| Subjects: | |
| Online Access: | http://scholars.utp.edu.my/id/eprint/1291/ http://scholars.utp.edu.my/id/eprint/1291/1/EN016-ICET_09-Carrol.pdf |
| _version_ | 1848659099392147456 |
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| author | Ng , C.Y. Kurian, V.J. Mohamed , M.A.W. |
| author_facet | Ng , C.Y. Kurian, V.J. Mohamed , M.A.W. |
| author_sort | Ng , C.Y. |
| building | UTP Institutional Repository |
| collection | Online Access |
| description | Abstract
This paper presents the numerical hydrodynamic analysis for the motion responses of spar offshore platforms in regular sea waves using both Morison Equation and Diffraction Method. The spar was modeled as a rigid body with three degrees of freedom restrained by mooring lines affecting the stiffness values. Linear Airy wave theory and Morison’s equation were used for calculating the wave forces on the
structure in the first case. The mass, damping and stiffness matrices were evaluated at every time step and
the equations of motion were formulated for the platform dynamic equilibrium. The equations were solved
using Newmark’s Beta time domain dynamic analysis method. The results were obtained as Transfer Functions in Surge. In the second case, the Transfer Functions were obtained using a linear diffraction Method. The results were compared and conclusions arrived at. It was observed that the responses using diffraction method were higher than that using Morison Equation for the low frequencies and vice versa for the high frequency.
Keywords
Spar platforms, Hydrodynamic analysis, Degree of freedom (DOF), Morison modified equations,
Diffraction method, and Transfer function. |
| first_indexed | 2025-11-13T07:25:02Z |
| format | Conference or Workshop Item |
| id | oai:scholars.utp.edu.my:1291 |
| institution | Universiti Teknologi Petronas |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-13T07:25:02Z |
| publishDate | 2009 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | oai:scholars.utp.edu.my:12912017-03-20T01:56:59Z http://scholars.utp.edu.my/id/eprint/1291/ Diffraction method for spar platforms Ng , C.Y. Kurian, V.J. Mohamed , M.A.W. TC Hydraulic engineering. Ocean engineering TA Engineering (General). Civil engineering (General) Abstract This paper presents the numerical hydrodynamic analysis for the motion responses of spar offshore platforms in regular sea waves using both Morison Equation and Diffraction Method. The spar was modeled as a rigid body with three degrees of freedom restrained by mooring lines affecting the stiffness values. Linear Airy wave theory and Morison’s equation were used for calculating the wave forces on the structure in the first case. The mass, damping and stiffness matrices were evaluated at every time step and the equations of motion were formulated for the platform dynamic equilibrium. The equations were solved using Newmark’s Beta time domain dynamic analysis method. The results were obtained as Transfer Functions in Surge. In the second case, the Transfer Functions were obtained using a linear diffraction Method. The results were compared and conclusions arrived at. It was observed that the responses using diffraction method were higher than that using Morison Equation for the low frequencies and vice versa for the high frequency. Keywords Spar platforms, Hydrodynamic analysis, Degree of freedom (DOF), Morison modified equations, Diffraction method, and Transfer function. 2009 Conference or Workshop Item PeerReviewed application/pdf en http://scholars.utp.edu.my/id/eprint/1291/1/EN016-ICET_09-Carrol.pdf Ng , C.Y. and Kurian, V.J. and Mohamed , M.A.W. (2009) Diffraction method for spar platforms. In: 2nd International Conference on Construction Technology, 8-10 December 2009, Kuala Lumpur. |
| spellingShingle | TC Hydraulic engineering. Ocean engineering TA Engineering (General). Civil engineering (General) Ng , C.Y. Kurian, V.J. Mohamed , M.A.W. Diffraction method for spar platforms |
| title | Diffraction method for spar platforms |
| title_full | Diffraction method for spar platforms |
| title_fullStr | Diffraction method for spar platforms |
| title_full_unstemmed | Diffraction method for spar platforms |
| title_short | Diffraction method for spar platforms |
| title_sort | diffraction method for spar platforms |
| topic | TC Hydraulic engineering. Ocean engineering TA Engineering (General). Civil engineering (General) |
| url | http://scholars.utp.edu.my/id/eprint/1291/ http://scholars.utp.edu.my/id/eprint/1291/1/EN016-ICET_09-Carrol.pdf |