Hydrodynamic interactions and relative motions of floating bodies in waves

Floating structures play an important role in sea transportation as well as exploration, drilling and production of oil and gas around the world. Hydrodynamic interaction of two platforms floating close to each other affects their motion responses which hinder the loading, unloading and production o...

Full description

Saved in:

Bibliographic Details
Main Author:	Abyn, Hassan
Format:	Thesis
Language:	English
Published:	2014
Subjects:	TJ Mechanical engineering and machinery
Online Access:	http://eprints.utm.my/id/eprint/78070/1/HassanAbynPFKM2014.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.78070
record_format	uketd_dc
spelling	my-utm-ep.780702018-07-23T06:05:55Z Hydrodynamic interactions and relative motions of floating bodies in waves 2014-12 Abyn, Hassan TJ Mechanical engineering and machinery Floating structures play an important role in sea transportation as well as exploration, drilling and production of oil and gas around the world. Hydrodynamic interaction of two platforms floating close to each other affects their motion responses which hinder the loading, unloading and production operation of the floating structures. The hydrodynamic interaction between two floating bodies may lead to large amplitude motions due to low damping in low frequency. This behavior induces enormous loading in mooring system and thus possibility of the mooring system failure increases. In this research, 3D source distribution panel technique was used to find a numerical solution in frequency domain based on the potential flow theory. It was developed to compute the motions of offshore structure. For computations of the motions and relative motions of two floating offshore structures, HydroStar (Hydrodynamic analysis software developed by Bureau Veritas) was also used. In order to validate the results, model tests were carried out at the Towing Tank, Universiti Teknologi Malaysia for a semisubmersible in the vicinity of a Tension Leg Platform. The tests were conducted in a head sea condition at regular wave. Due to the limitation of water depth in the towing tank, vertical forces of the moorings were ignored and horizontal forces were modeled by horizontal mechanical spring connectors. The results obtained from the developed code, HydroStar and experimental results for a semisubmersible show a very good agreement which proves the efficiency and effectiveness of the 3D source distribution technique. Computations were also carried out for two bodies at different separation distances, wave headings and wave frequencies by using HydroStar. The results show an increase in the relative motion owing to the sheltering effect. It implies that decreasing the distance would increase the probability of accidents. From extensive numerical computations, experiments, it is concluded that a minimum gap must be maintained in order to perform safe operation. An empirical formula is also proposed from the current research for finding the minimum gap between the two structures. 2014-12 Thesis http://eprints.utm.my/id/eprint/78070/ http://eprints.utm.my/id/eprint/78070/1/HassanAbynPFKM2014.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:98452 phd doctoral Universiti Teknologi Malaysia, Faculty of Mechanical Engineering Faculty of Mechanical Engineering
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	TJ Mechanical engineering and machinery
spellingShingle	TJ Mechanical engineering and machinery Abyn, Hassan Hydrodynamic interactions and relative motions of floating bodies in waves
description	Floating structures play an important role in sea transportation as well as exploration, drilling and production of oil and gas around the world. Hydrodynamic interaction of two platforms floating close to each other affects their motion responses which hinder the loading, unloading and production operation of the floating structures. The hydrodynamic interaction between two floating bodies may lead to large amplitude motions due to low damping in low frequency. This behavior induces enormous loading in mooring system and thus possibility of the mooring system failure increases. In this research, 3D source distribution panel technique was used to find a numerical solution in frequency domain based on the potential flow theory. It was developed to compute the motions of offshore structure. For computations of the motions and relative motions of two floating offshore structures, HydroStar (Hydrodynamic analysis software developed by Bureau Veritas) was also used. In order to validate the results, model tests were carried out at the Towing Tank, Universiti Teknologi Malaysia for a semisubmersible in the vicinity of a Tension Leg Platform. The tests were conducted in a head sea condition at regular wave. Due to the limitation of water depth in the towing tank, vertical forces of the moorings were ignored and horizontal forces were modeled by horizontal mechanical spring connectors. The results obtained from the developed code, HydroStar and experimental results for a semisubmersible show a very good agreement which proves the efficiency and effectiveness of the 3D source distribution technique. Computations were also carried out for two bodies at different separation distances, wave headings and wave frequencies by using HydroStar. The results show an increase in the relative motion owing to the sheltering effect. It implies that decreasing the distance would increase the probability of accidents. From extensive numerical computations, experiments, it is concluded that a minimum gap must be maintained in order to perform safe operation. An empirical formula is also proposed from the current research for finding the minimum gap between the two structures.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Abyn, Hassan
author_facet	Abyn, Hassan
author_sort	Abyn, Hassan
title	Hydrodynamic interactions and relative motions of floating bodies in waves
title_short	Hydrodynamic interactions and relative motions of floating bodies in waves
title_full	Hydrodynamic interactions and relative motions of floating bodies in waves
title_fullStr	Hydrodynamic interactions and relative motions of floating bodies in waves
title_full_unstemmed	Hydrodynamic interactions and relative motions of floating bodies in waves
title_sort	hydrodynamic interactions and relative motions of floating bodies in waves
granting_institution	Universiti Teknologi Malaysia, Faculty of Mechanical Engineering
granting_department	Faculty of Mechanical Engineering
publishDate	2014
url	http://eprints.utm.my/id/eprint/78070/1/HassanAbynPFKM2014.pdf
_version_	1747817899654905856

Hydrodynamic interactions and relative motions of floating bodies in waves

Similar Items