DIMPACT

Design of FOWT and IMPACTs of energetic steep and breaking waves

Project leader France Energies Marines
Industrials partners EQUINOR, MORPHOSENSE, SAIPEM, EOLFI, EDF R&D,
Research partners ISMAR, SENCC (NORWAY), URI, CEREMA, ENPAC, ENSTA BRETAGNE, IFREMER
Budget 2 144 K€
Year of labeling 2021

When designing offshore wind turbines (OWT) for a specific site, the industry has to analyze the Ultimate Limit State (ULS) of the structure, i.e. the maximum expected response that the OWT will experience over its lifetime (DNV, 2014; IEC, 2009). In the assessment of the ULS, the effects of energetic steep or breaking waves (hereinafter ESBW) are thought to be responsible for “considerable uncertainties” (Chella & al. 2012). As well documented in the Oil&Gas or fixed OWT literature, ESBW may excite the first structural modes, cause damages due to vertical water excursion (runup), water over deck (green water) or local deteriorations due to slamming loads. Numerical modeling of a full-scale Floating OWT (FOWT) even showed that the blade tips could hit the water in presence of realistic ESBW (Jonkman, 2007).

 

A lack of proper methodology to estimate their effects on OWTs.

 

The above-cited shortcomings are even more critical in the case of FOWTs since the observations of ESBW in deep water storms conditions are extremely difficult to collect and because their impacts on a moving floating structure with an arbitrary geometry are more complex to capture.

 

The objective of DIMPACT is to fill these gaps by proposing a research program combining a set of experimental, numerical and methodological efforts aiming to provide the FOWT industry with less conservative certification guidelines and an appropriate engineering tool accounting for the effect of ESBW in terms of slamming loads.