Linear Hydrodynamics


Submitted by Martijn van Roermund on September 10, 2015 - 11:32am
Main hypothesis
The computer program Phatas, ”Program for Horizontal Axis wind Turbine Analysis and Simulation”, is developed for the time-domain calculation of the dynamic behaviour and the corresponding loads on a Horizontal Axis wind Turbine. Phatas calculates the dynamic response of a wind turbine that covers the structural dynamic deformation of the turbine structure, the unsteady aerodynamic loads on the blades and tower, and the interactions from an operational controller and a Supervisory controller. The mutual equilibrium between all these sub-models is obtained by performing each time step an iterative solution of the full non-linear set of coupled equations. The program Phatas is developed as a tool under the design package FOCUS6, maintained by WMC. Within FOCUS6, the aerodynamic capabilities can be extended by linking Phatas to external calculation modules, such as the ECN Aeromodule.

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.