Application of a lumping method for fatigue design of monopile-based wind turbines using fully coupled and simplified models

In the present paper, a new fully coupled simulator based on DeepLines™ software is described in order to address floating wind turbines dynamic simulation. It allows its user to take into account either separately or together the hydrodynamic and aerodynamic effects on one or several floating wind turbines. This simulator includes a non linear beam finite elements formulation to model the structural components — blades, tower, drivetrain, mooring lines and umbilicals — for both HAWT and VAWT layouts and advanced hydrodynamic capabilities to define all kinds of floating units and complex environmental loadings. The floating supports are defined with complete hydrodynamic databases computed with a seakeeping program. The aerodynamic loads acting on the turbine rotor are dynamically computed by an external aerodynamic library, which first release includes BEM (blade element moment for HAWTs) and SSM (single streamtube method for VAWTs) methods. The integration in time is performed with an implicit Newmark integration scheme.

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Stress-cycle fatigue design with Kriging applied to offshore wind turbines

International Journal of Fatigue ◽

10.1016/j.ijfatigue.2019.04.012 ◽

2019 ◽

Vol 125 ◽

pp. 454-467 ◽

Cited By ~ 9

Author(s):

Rui Teixeira ◽

Maria Nogal ◽

Alan O’Connor ◽

James Nichols ◽

Antoine Dumas

Keyword(s):

Wind Turbines ◽

Offshore Wind ◽

Cycle Fatigue ◽

Stress Cycle ◽

Offshore Wind Turbines ◽

Fatigue Design

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A Fully Coupled Computational Fluid Dynamics Method for Analysis of Semi-Submersible Floating Offshore Wind Turbines Under Wind-Wave Excitation Conditions Based on OC5 Data

Applied Sciences ◽

10.3390/app8112314 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2314 ◽

Cited By ~ 5

Author(s):

Yin Zhang ◽

Bumsuk Kim

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Wind Turbine ◽

Wind Turbines ◽

Wind Wave ◽

Offshore Wind ◽

Wave Excitation ◽

Offshore Wind Turbines ◽

Floating Offshore Wind Turbines ◽

Fully Coupled

Accurate prediction of the time-dependent system dynamic responses of floating offshore wind turbines (FOWTs) under aero-hydro-coupled conditions is a challenge. This paper presents a numerical modeling tool using commercial computational fluid dynamics software, STAR-CCM+(V12.02.010), to perform a fully coupled dynamic analysis of the DeepCwind semi-submersible floating platform with the National Renewable Engineering Lab (NREL) 5-MW baseline wind turbine model under combined wind–wave excitation environment conditions. Free-decay tests for rigid-body degrees of freedom (DOF) in still water and hydrodynamic tests for a regular wave are performed to validate the numerical model by inputting gross system parameters supported in the Offshore Code Comparison, Collaboration, Continued, with Correlations (OC5) project. A full-configuration FOWT simulation, with the simultaneous motion of the rotating blade due to 6-DOF platform dynamics, was performed. A relatively heavy load on the hub and blade was observed for the FOWT compared with the onshore wind turbine, leading to a 7.8% increase in the thrust curve; a 10% decrease in the power curve was also observed for the floating-type turbines, which could be attributed to the smaller project area and relative wind speed required for the rotor to receive wind power when the platform pitches. Finally, the tower-blade interference effects, blade-tip vortices, turbulent wakes, and shedding vortices in the fluid domain with relatively complex unsteady flow conditions were observed and investigated in detail.

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