Abstract
Extreme sea states, which the IEC 61400-3 (2008) standard requires for the ultimate limit state (ULS) analysis of offshore wind turbines are derived to establish the design basis for the conceptual layout of deep water floating offshore wind turbine foundations in hurricane affected areas. Especially in the initial phase of floating foundation concept development, site specific metocean data are usually not available. As the areas of interest are furthermore not covered by any design standard, in terms of design sea states, generic and in engineering terms applicable environmental background data is required for a type specific conceptual design. ULS conditions for different return periods are developed, which can subsequently be applied in siteindependent analysis and conceptual design. Recordings provided by National Oceanic and Atmospheric Administration (NOAA), of hurricanes along the US east coast and the Gulf of Mexico (1851 - 2009) and Japanese east coast (1951 -2009) form the basis for Weibull extreme value analyses to determine return period respective maximum wind speeds. Unidirectional generic sea state spectra are obtained by application of the empirical models for hurricane generates seas by Young (1998, 2003, and 2006), requiring maximum wind speeds, forward velocity and radius to maximum wind speed. An averaged radius to maximum sustained wind speeds, according to Hsu et al. (1998) and averaged forward speed of cyclonic storms are applied in the initial state. In a second step the influence of the forward velocity is investigated and related to the assumption of an extended fetch.
Original language | English |
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Title of host publication | Proceedings of the Twenty-second (2012) International Offshore and Polar Engineering Conference |
Number of pages | 11 |
Publisher | International Society of Offshore & Polar Engineers |
Publication date | 2012 |
Pages | 469-479 |
ISBN (Electronic) | 978-1-880653-94−4 |
Publication status | Published - 2012 |
Event | International Ocean and Polar Engineering Conference 2012 - Ixia, Rhodes, Greece Duration: 17 Jun 2012 → 23 Jun 2012 Conference number: 22 |
Conference
Conference | International Ocean and Polar Engineering Conference 2012 |
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Number | 22 |
Country/Territory | Greece |
City | Ixia, Rhodes |
Period | 17/06/2012 → 23/06/2012 |
Series | Proceedings of the International Offshore and Polar Engineering Conference |
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Number | 22 |
ISSN | 1098-6189 |
Keywords
- Hurricane Waves
- Extreme Sea State
- Ultimate Limit State