Flexible dynamic analysis of an offshore wind turbine installed on a floating spar platform

This paper is concerned with the development of a Floating Offshore Wind Turbine (FOWT) utilizing spar-type floating foundation. In order to design such a structure, it is essential to evaluate the dynamic response under extreme environmental conditions. In this study, therefore, a dynamic analysis tool has been developed. The dynamic analysis tool consists of a multi-body dynamics solver (MSC.Adams), aerodynamic force evaluation library (NREL/AeroDyn), hydrodynamic force evaluation library (In-house program named SparDyn), and mooring force evaluation library (In-house program named Moorsys). In this paper, some details of the developed dynamic analysis tool are given. In order to validate the program, comparison with the experimental results, where the wind, current and wave are applied simultaneously, has been made. The comparison shows that satisfactory agreements between the simulation and the experimental results are obtained. However, when VIM (Vortex Induced Motion) occurs, the current loads and cross flow responses (sway and roll) are underestimated by the simulation since the simulation code does not account for the effect of VIM.

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Analysis of Working Condition and Load Direction for Tripod Substructure of Offshore Wind Turbine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.454.27 ◽

2013 ◽

Vol 454 ◽

pp. 27-33

Author(s):

Bin Wang ◽

Ying Li ◽

Na Lv ◽

Bin Bin Zhu ◽

Wei Li

Keyword(s):

Dynamic Analysis ◽

Wind Turbine ◽

Working Condition ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Load Direction ◽

Element Analysis ◽

Static And Dynamic Analysis ◽

The Finite Element Analysis ◽

Control Load

The control working condition and the control load direction of the typical Tripod substructure for the offshore wind turbine are studied by the finite element analysis software SACS. The results show that the different control criterions are corresponding to the different control working conditions for the Tripod substructure of the offshore wind turbine, and the control load directions vary with the structure form and the marine environments. Therefore, the static and dynamic analysis of the offshore wind turbine substructure in the single or limited load directions cant reflect the static and dynamic characteristic of the structure sufficiently. The multidirectional static and dynamic analysis of the offshore wind turbine structure has to be carried out.

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Aero-Elastic-Floater-Mooring Coupled Dynamic Analysis of FOWT (Floating Offshore Wind Turbine) in Maximum Operation and Survival Conditions

Volume 4: Offshore Geotechnics; Ronald W. Yeung Honoring Symposium on Offshore and Ship Hydrodynamics ◽

10.1115/omae2012-83545 ◽

2012 ◽

Cited By ~ 1

Author(s):

Y. H. Bae ◽

M. H. Kim ◽

Q. Yu ◽

J. K. Heo

Keyword(s):

Dynamic Analysis ◽

Wind Turbine ◽

Clean Energy ◽

Offshore Wind ◽

Irregular Waves ◽

Offshore Wind Turbine ◽

Coupled Dynamic Analysis ◽

Floating Offshore Wind Turbines ◽

Mooring Dynamics ◽

Dynamics And Control

Increasing numbers of FOWTs (floating offshore wind turbines) are planned in the coming years due to their high potential in massive generation of clean energy from ocean-wind. In the present study, a numerical prediction tool has been developed for the fully coupled dynamic analysis of an FOWT system in time domain including aero-loading, blade-rotor dynamics and control, mooring dynamics, and platform motions so that the influence of rotor-control dynamics on the hull-mooring performance and vice versa can be assessed. Hywind spar design with 5MW turbine is selected as an example, and two different environmental conditions, maximum operational and survival conditions, are applied for this study. The maximum operational condition means the maximum environmental condition that wind turbine can work normally, and the survival condition represents the extreme situation without any blade-turbine operation. Through this study, it is seen that the design environments for different structural components of FOWT can be different. The developed technology and numerical tool are readily applicable to the design of any future FOWTs in any combinations of irregular waves, dynamic winds, and steady currents.

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