An efficient frequency-domain model for quick load analysis of floating offshore wind turbines
<p>A model for Quick Load Analysis of Floating wind turbines (QuLAF) is presented and validated here. The model is a linear, frequency-domain, efficient tool with four planar degrees of freedom: floater surge, heave, pitch and first tower modal deflection. The model relies on state-of-the-a...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-10-01
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| Series: | Wind Energy Science |
| Online Access: | https://www.wind-energ-sci.net/3/693/2018/wes-3-693-2018.pdf |
| Summary: | <p>A model for Quick Load Analysis of Floating wind turbines (QuLAF) is
presented and validated here. The model is a linear, frequency-domain,
efficient tool with four planar degrees of freedom: floater surge, heave,
pitch and first tower modal deflection. The model relies on state-of-the-art
tools from which hydrodynamic, aerodynamic and mooring loads are extracted
and cascaded into QuLAF. Hydrodynamic and aerodynamic loads are pre-computed
in WAMIT and FAST, respectively, while the mooring system is linearized
around the equilibrium position for each wind speed using MoorDyn. An
approximate approach to viscous hydrodynamic damping is developed, and the
aerodynamic damping is extracted from decay tests specific for each degree of
freedom. Without any calibration, the model predicts the motions of the
system in stochastic wind and waves with good accuracy when compared to FAST.
The damage-equivalent bending moment at the tower base is estimated with
errors between 0.2 % and 11.3 % for all the load cases
considered. The largest errors are associated with the most severe wave
climates for wave-only conditions and with turbine operation around rated
wind speed for combined wind and waves. The computational speed of the model
is between 1300 and 2700 times faster than real time.</p> |
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| ISSN: | 2366-7443 2366-7451 |