Wind energy research: Improved Offshore Wave Load Simulation

Objectives

Reduce the Cost of Energy of offshore wind energy by providing designers with a validated tool for improved wave and current load analysis on individual offshore support structure members.

Project summary

Currently, state-of-the-art integrated wind turbine design software makes use of methods to reduce the complexity of the full Finite Element support structure model for the time-dependent aero- and hydro-elastic analysis of a wind turbine and support structure system. Verification of simulation results in previous benchmark projects has shown that global turbine response is simulated satisfactorily.

However, results of INNWIND.EU and DOWNVinD research projects indicate that the wave and current loading on the individual members of a jacket tower are important, which is not covered by using reduced-system solutions. For an optimal integrated design solution, the modelling of local wave and current loading in integrated design tools needs to improved. A good understanding of numerical aspects relevant to implementation of the hydrodynamical model is required. Therefore the first part of the research is dedicated to validating the existing hydrodynamic model implementation in PHATAS. This is done using experimental wave tank test data on cylinders, which are available within the IEA OC5 project.

The integrated wind turbine design tool FOCUS6 is modified to allow advanced modelling of wave and current loading on individual members of a wind turbine support structure. A study is performed on a representative turbine and support structure combination to compare the newly-developed advanced wave and current loading tool to a current state-of-the-art reduced-system tool. This leads to understanding for which design load cases the local wave and current loading, which is not taken into account in reduced-system solutions, does have a significant effent on support structure member behaviour.

Expected results

  • Validation of the implementation of the hydrodynamic modelling in the FOCUS6 turbine design tool by means of comparison with experimental data available in the IEA OC5 project.
  • Modified version of FOCUS6 to allow advanced modelling of wave and current loading on individual members of a wind turbine support structure.
  • Guidelines on best practices for the level of detail required in support structure modelling for specific load cases. These will be based on a study using a representative support structure model and a turbine model provided by XEMC Darwind.

Organisation

Project partners: WMC, XEMC Darwind
Period: January 2015 - December 2015
Project partially funded by: FLOW (project P201406-004-WMC)
Project coordinator: Tjeerd van der Zee (WMC)

Contact

For inquiries please contact:

Knowledge Centre WMC
Kluisgat 5
1771 MV Wieringerwerf
the Netherlands
phone +31(0)227-50 49 49
info@wmc.eu