Category Archives: Open-source projects

BEMRosetta

Boundary Element Methods are extensively used to model hydrodynamic forces in offshore devices like ships, offshore wind platforms and wave energy converters. These solvers use device geometry mesh to get some hydrodynamics coefficients as radiation damping, added mass, wave diffraction force, and wave excitation force. All these data is saved in file formats incompatible between them. These may avoid to use the coefficients between programs.

BEMRosetta allows to load the hydrodynamic coefficients from a format saving it in another. In addition it allows to compare the results obtained between programs, the results between similar geometries and the same geometry with different discretization levels.

In addition, BEMRosetta allows to view and visually compare the meshes from different programs.

BEMRosetta runs on Windows and Linux, it is done in C++ so install is simple, and it includes a GUI and a command line version.

Actually, BEMRosetta opens files from:

  • Wamit: .out, .3sc, 3fk, .1, .3, .4, .hst
  • Nemoh: Nemoh.cal, Mesh/Hydrostatics*.dat, Mesh/KH*.dat, RadiationCoefficients.tec, ExcitationForce.tec, DiffractionForce.tec, FKForce.tec, IRF.tec
  • FAST-Wamit: HydroDyn.dat, .1, .3, .hst
  • SeaFEM-Nemoh: .flavia.inf, RadiationCoefficients.tec, ExcitationForce.tec, DiffractionForce.tec, FKForce.tec
  • Ansys AQWA: .LIS, .AH1
  • COER FOAMM: .mat

BEMRosetta is free source. You can find all the code and resources in the Github page.

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DTOcean

dtocean

DTOcean, which stands for Optimal Design Tools for Ocean Energy Arrays, aims at at accelerating the industrial development of ocean energy power generation knowledge, and providing design tools for deploying the first generation of wave and tidal energy converter arrays. It gathers 18 partners from 11 countries (Ireland, Spain, United Kingdom, Germany, Portugal, France, Norway, Denmark, Sweden, Belgium and United States of America) under the coordination of the University of Edinburgh.

DTOcean work planning has been implemented as five content-orientated Work Packages (Hydrodynamics, Electrical Sub-systems, Moorings & Foundations, Installation and Operations & Maintenance) guided by two defining work packages (Scenarios and Management & Coordination) which set the underpinning scope in relation to a range of array sizes and hydrodynamic layouts. The outputs, feedbacks and interactions within these culminate in the Integration Work Package where the design tools are actually developed.

The newly released, open-source, integrated DTOcean v1.0 software package can be downloaded here.

MoorDyn, an open-source mooring model

segments

 

MoorDyn is a lumped-mass mooring line model designed for easy coupling with other software (i.e. floating platform models). It supports arbitrary line interconnections, clump weights and floats, and different line properties. The model accounts for internal axial stiffness and damping forces, weight and buoyancy forces, hydrodynamic forces from Morison’s equation, and vertical spring-damper forces from contact with the seabed.

The original version is written in C++ and has been successfully coupled with FAST v7 and other tools/models in Matlab and Simulink. A separate Fortran-based version has recently been incorporated into FAST v8 (nwtc.nrel.gov/FAST8). More information and downloads can be found at www.matt-hall.ca/software/moordyn.

Wave Farm Code – mwave

bitmap

Wave energy converters (WECs) will be deployed in groups or “wave farms”. The hydrodynamic interactions between WECs in a wave farm (i.e. how waves that are absorbed, scattered, or radiated by one WEC affect the others) will have siginificant impacts on the overall power performance of the wave farm.

A recently published paper by researchers at The University of Edinburgh titled “A novel method for deriving the diffraction transfer matrix and its application to multi-body interactions in water waves” presents a new method for computing wave farm performance with results from commercial software. Using the theory, WEC array interactions can be computed on the order of 1,000-10,000 times faster than with standard methods.  However, the method presented in the paper is still somewhat complicated to implement, which would make it difficult for others to employ it.

Open source to the rescue! The authors have chosen to share the wave farm code used in the paper for free. The Matlab package that they developed, including examples of WEC array performance, can be found on GitHub:

mwave

The authors chose to release the code to increase the impact of the work. The code is already being used by another researcher at Oregon State University as part of his wave farm design optimization work and is being evaluated for use by the International DTOcean project, which “aims at accelerating the industrial development of ocean energy power generation knowledge, and providing design tools for deploying the first generation of wave and tidal energy converter arrays.”