Tag Archives: NREL

WEC3: codes that work


At EWTEC 2015, a great project wave presented: WEC3 (pronounced WEC cubed), which stands for Wave Energy Converter Code Comparison. From their EWTEC paper (which can be found here):

The objectives of WEC3 are to verify and validate numerical modelling tools that have been developed specifically to simulate wave energy conversion devices and to inform the upcoming IEA OES Annex VI Ocean Energy Modelling Verification and Validation project. WEC3 is divided into two phases. Phase 1 consists of a code-to-code verification and Phase II entails code-to-experiment validation.

The codes under consideration are:

Comparison of codes to one another and to experiments benefits the code developers, giving them confidence in their results (something which is very important in numerical modelling), and benefits the community as a whole, providing validated tools for WEC design.

WEC-Sim Version 1.2

Version 1.2 of WEC-Sim is now available on GitHub, and there are lots of great updates!

The NREL/SNL team is also implementing a multi-branch approach, allowing users to use the stable ‘master’ branch or the more advanced/under development ‘dev’ branch.

Updates in ‘master’

  • Nonlinear Froude-Krylov hydrodynamics and hydrostatics
  • State space radiation
  • Wave directionality
  • User-defined wave elevation time-series
  • Imports non-dimensionalized BEMIO hydrodynamic data (instead of fully dimensional coefficients)
  • ‘Variant Subsystems’ implemented to improve code stability (instead of if statements)
  • Bug fixes

Updates in ‘dev’:

  • Morison Elements
  • Body2Body Interactions

WEC-Sim (Wave Energy Converter SIMulator) is an open source wave energy converter simulation tool being developed as a joint effort between the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL) with funding from the U.S. Department of Energy’s Wind and Water Power Technologies Office.  The code is developed in MATLAB/SIMULINK using the multi-body dynamics solver SimMechanics. WEC-Sim has the ability to model devices that are comprised of rigid bodies, power-take-off systems, and mooring systems. Simulations are performed in the time-domain by solving the governing WEC equations of motion in 6 degrees-of-freedom as described in the WEC-Sim Theory Manual.

The NREL/SNL team would like to receive feedback on how WEC-Sim can be improved in the future and to facilitate this process a questionnaire has been created.  It is highly encouraged of all users to fill out the questionnaire as soon as possible.  Thank you for your time and please direct any questions about the current release to Nathan Tom, Nathan.tom@nrel.gov.