Cost reduction within offshore wind energy is central for achieving the 2020 goal of 50% wind share of the Danish electricity supply. DeRisk provides a key contribution by providing new design methods with reduced risk and uncertainty for extreme wave loads (ULS, Ultimate Limit State) which are often design-giving for the support structure.
DeRisk examines the design chain from met-ocean data to structural response. Joint-probability methods are developed for analysis of met-ocean data. Wave transformation over depth is computed with ground-breaking fully nonlinear, GPU-accelerated wave models. The detailed physical load effects of 3D wave spreading, bed-slope, wave-current interaction and formation of extreme irregular waves are quantified experimentally. Specialised tools for high-frequency ringing-type and breaking wave loads are developed. Advanced LES-based CFD methods are developed and applied to extreme wave impacts with wall friction.
The structural response for wind turbine structures of mono-pod and jacket type are examined through aero-elastic calculations and analysis of lab and field data. For the first time, new methods for numerical uncertainty quantification are applied to quantify the model sensitivity. The new tools and detailed investigations are synthesized into a de-risked design procedure for ULS wave loads (see figure below).