FEM Mooring

FAST v8 + OrcaFlex 10.1

Submitted by Josean Galvan on August 27, 2015 - 11:55am
Main hypothesis
FAST is a wind turbine modelling program developed by the US National Renewable Energy Laboratory (NREL). FASTlink is an experimental package that can be used to run coupled OrcaFlex + FAST simulations of floating wind turbine systems. In such coupled simulations FAST models the turbine aerodynamic loads and response, and the turbine control and power take-off system, but OrcaFlex models the platform hydrodynamic loads and mooring loads and response.

hGAST v1

Submitted by Marinos Manolesos on August 26, 2015 - 5:47pm
Main hypothesis
hGAST is an advanced, nonlinear hydro-servo-aero-elastic simulator for WTs. It performs time domain simulations, modal analysis as well as stability analysis. The structure (blades, shaft, tower and support structure) is divided into a number of interconnected bodies and sub-bodies based on the multi-body formulation. Each deformable body is modeled as a Timoshenko beam subjected to combined bending in 2 directions including shear, torsion and extension and solved using the FEM. A dynamic mooring line model defines the mooring contribution based on nonlinear, co-rotational truss elements following the FEM context. The floater is either modeled as a rigid body or as a multi-membered FEM structure. The aerodynamic loads are estimated either using the standard BEM method including corrections and add-on's or the 3D free wake vortex particle method GenUVP. Both methods apply the ONERA dynamic stall model. The hydrodynamic loads are estimated either using potential theory (linear and Newman's approximation) or Morison's equation.


Submitted by Anders Yde on August 24, 2015 - 2:00pm
Main hypothesis
HAWC2 consists of models describing the external effect, applied loads, structural dynamics and connection to the control system. The external effects models how the wind, waves and soil is expected to behave. The applied loads models how the external effects interact with the structure through aerodynamic, hydrodynamic and soil models. The structural formulation of HAWC2 is based on a multibody system. This enables a wide range of model capabilities and the possibility to include non-linear geometric effects. Wind turbine control is preformed through external DLL´s (Dynamic Link Library) that operates the system under different conditions.