• norsk
    • English
  • English 
    • norsk
    • English
  • Login
View Item 
  •   Home
  • Fakultet for ingeniørvitenskap (IV)
  • Institutt for marin teknikk
  • View Item
  •   Home
  • Fakultet for ingeniørvitenskap (IV)
  • Institutt for marin teknikk
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Hydrodynamic Modelling Effects on Fatigue Calculations for Monopile Offshore Wind Turbines

Malik, Mohibb Ghani
Master thesis
Thumbnail
View/Open
14201_FULLTEXT.pdf (7.295Mb)
14201_COVER.pdf (1.556Mb)
URI
http://hdl.handle.net/11250/2397919
Date
2016
Metadata
Show full item record
Collections
  • Institutt for marin teknikk [2357]
Abstract
For shallow and intermediate water depths, monopile foundations are the most

commonly used concept, and is considered the most promising with respect to

the cost of energy. The typical highest structural eigenperiods of these structures

are usually between 3-5 seconds, and often coincide with the wave frequencies.

Estimates of the fatigue life is therefore very dependent on accurate

hydrodynamic modeling of the wave forces. In these cases, the waves are often

relatively short compared to the structure, and the often used Morison s Equation

is no longer accurate, as it does not account for diffraction.

In this thesis, a comparison between the standard Morison s equation and

MacCamy-Fuchs diffraction theory has been performed. The responses and fatigue

life of a 5 MW wind turbine was investigated, using both hydrodynamic

theories.

The analyses showed that the wind turbine experienced small differences

as a result of the hydrodynamic modeling. Since wave diffraction affects small

waves, the results were different at different depths. At the mean sea level,

MacCamy-Fuchs resulted in approximately 3% lower fatigue damage. However,

at the bottom, where only the large waves affect the structure, MacCamy-Fuchs

resulted in approximately 3 % higher fatige. This suggests that the wind turbine

in question is not very sensitive to diffraction.

It was however seen that the fatigue damage was dominated by load cases

with large aerodynamic thrust, suggesting that the structure is more sensitive

to aerodynamic loads than hydrodynamic loads, as should be expected from a

monopile structure at shallow water depth.
Publisher
NTNU

Contact Us | Send Feedback

Privacy policy
DSpace software copyright © 2002-2019  DuraSpace

Service from  Unit
 

 

Browse

ArchiveCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsDocument TypesJournalsThis CollectionBy Issue DateAuthorsTitlesSubjectsDocument TypesJournals

My Account

Login

Statistics

View Usage Statistics

Contact Us | Send Feedback

Privacy policy
DSpace software copyright © 2002-2019  DuraSpace

Service from  Unit