A Coupled Method for Dynamic Analysis of Offshore Floating Wind Turbine System

2012 ◽  
Vol 220-223 ◽  
pp. 841-844
Author(s):  
Fa Suo Yan ◽  
Peng Fei Shen ◽  
Hong Wei Wang ◽  
Jun Zhang
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Numerical Results ◽  
Hydrodynamic Performance ◽  
Numerical Code ◽  
Response Analysis ◽  
Coupled Method ◽  
Floating Base ◽  
Floating Wind Turbine ◽  
Wind Turbine System

A coupled dynamic analysis method is introduced for numerical simulation of floating wind turbine systems in this paper. A numerical code，which has been developed to perform couple hydrodynamic analysis of floating body together with its mooring system, is extended to collaborate with wind turbine simulator to evaluate the interactions between wind turbine and its floating base. To verify the coupled method, a dynamic response analysis of a spar type floating wind turbine system (NREL offshore-5MW baseline wind turbine) is carried out separately by the coupled Morison method and radiation-diffraction theory. Numerical results and comparison are presented. It turns out that this coupled method is competent enough to predict hydrodynamic performance of floating wind turbine system. The numerical results derived in this study may provide crucial information for the design of a floating wind turbine in the near future.

Dynamic Response of an Offshore Wind Turbine System Using Coupled and Limited Coupled Methods

2012 ◽  
Author(s):  
Fasuo Yan ◽  
Cheng Peng ◽  
Jun Zhang ◽  
Dagang Wang
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Wind Turbine ◽  
Numerical Code ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Time Step ◽  
Coupled Method ◽  
Floating Wind Turbine ◽  
Wind Turbine System

Offshore turbines are gaining attention as means to capture the immense and relatively calm wind resources available over deep waters. A coupled dynamic analysis is required to evaluate the interactions between the wind turbine, floating hull and its mooring system. In this study, a coupled hydro-aero dynamic response analysis of a floating wind turbine system (NREL offshore-5MW baseline wind turbine) is carried out. A numerical code, known as COUPLE, has been extended to collaborate with FAST for the simulation of the dynamic interaction. Two methods were used in the analysis; one is coupled method and the other is limited coupled method. In the coupled method, the two codes are linked at each time step to solve the whole floating system. The limited coupled method assumes wind load is from a turbine installed on top of a fixed base, namely it doesn’t consider real-time configuration of floating carrier at each time step. Coupled technique is also mentioned to integrate the hydro-aero dynamic analysis in this paper. Six-degrees of freedom motion and mooring tensions are presented and compared. The numerical results derived in this study may provide crucial information for the design of a floating wind turbine in the future.

Influence of Wind Turbine Aero-Elastic Load on Dynamic Response of Floating Platform

2012 ◽  
Vol 608-609 ◽  
pp. 649-652
Author(s):  
Fa Suo Yan ◽  
Hong Wei Wang ◽  
Jun Zhang ◽  
Da Gang Zhang
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Numerical Code ◽  
Floating Body ◽  
Response Analysis ◽  
Floating Platform ◽  
Floating Base ◽  
Wind Turbine System ◽  
The Difference

A numerical code, known as COUPLE, which has been developed to perform hydrodynamic analysis of floating body with a mooring system, is extended to collaborate with FAST to evaluate the interactions between wind turbine and its floating base. FAST is developed by National Renewable Energy Lab (NREL) for aeroelastic simulation of wind turbines. A dynamic response analysis of a spar type floating wind turbine system is carried out by the method. Two types of simulation of wind load are used in the analysis. One type is a constant steady force and the other is a six-component dynamic load from a turbulent wind model. Numerical results of related platform motions under random sea conditions are presented in time and frequency domain. Comparison of results is performed to explain the difference of two analyses. The conclusions derived in this study may provide reference for the design of offshore floating wind turbines.

Coupled Aerodynamic and Hydroelastic Analysis of an Offshore Floating Wind Turbine System Under Wind and Wave Loads

2010 ◽  
Author(s):  
Kazuhiro Iijima ◽  
Junghyun Kim ◽  
Masahiko Fujikubo
Keyword(s):  
Wind Turbine ◽  
Time Domain ◽  
Response Analysis ◽  
Wave Loads ◽  
Structural System ◽  
Floating Structure ◽  
Floating Wind Turbine ◽  
Wind Turbine System ◽  
Offshore Floating Wind Turbine ◽  
The Impact

A numerical procedure for the fully coupled aerodynamic and hydroelastic time-domain analysis of an offshore floating wind turbine system including rotor blade dynamics, dynamic motions and flexible deflections of the structural system is illustrated. For the aerodynamic analysis of wind turbine system, a design code FAST developed by National Renewable Energy Laboratory (NREL) is employed. It is combined with a time-domain hydroelasticity response analysis code ‘Shell-Stress Oriented Dynamic Analysis Code (SSODAC)’ which has been developed by one of the authors. Then, the dynamic coupling between the rotating blades and the structural system under wind and wave loads is taken into account. By using this method, a series of analysis for the hydroelastic response of an offshore large floating structure with two rotors under combined wave and wind loads is performed. The results are compared with those under the waves and those under the winds, respectively, to investigate the coupled effects in terms of stress as well as motions. The coupling effects between the rotor-blades and the motions are observed in some cases. The impact on the structural design of the floating structure, tower and blade is addressed.

Coupled dynamic response analysis of a multi-column tension-leg-type floating wind turbine

2016 ◽  
Vol 30 (4) ◽  
pp. 505-520 ◽  
Author(s):  
Yong-sheng Zhao ◽  
Jian-min Yang ◽  
Yan-ping He ◽  
Min-tong Gu
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Floating Wind Turbine

scholarly journals Integrated Optimization of Floating Wind Turbine Systems

2014 ◽  
Author(s):  
Frank Sandner ◽  
David Schlipf ◽  
Denis Matha ◽  
Po Wen Cheng
Keyword(s):  
Wind Turbine ◽  
Degrees Of Freedom ◽  
Dynamic Models ◽  
Controller Design ◽  
Coupled Model ◽  
Optimal Solution ◽  
Wave Loads ◽  
Nonlinear Simulation ◽  
Floating Wind Turbine ◽  
Wind Turbine System

The purpose of this paper is to show an exemplary methodology for the integrated conceptioning of a floating wind turbine system with focus on the spar-type hull and the wind turbine blade-pitch-to-feather controller. It is a special interest to use a standard controller, which is easily implementable, even at early design stages. The optimization of the system is done with adapted static and dynamic models through a stepwise narrowing of the design space according to the requirements of floating wind turbines. After selecting three spar-type hull geometries with variable draft a simplified nonlinear simulation model with four degrees of freedom is set up and then linearized including the aerodynamics with the blade pitch controller in the closed-loop. The linear system allows conventional procedures for SISO controller design giving a theoretically suitable range of controller gains. Subsequently, the nonlinear model is used to find the optimal controller gains for each platform. Finally, a nonlinear coupled model with nine degrees of freedom gives the optimal solution under realistic wind and wave loads.

Dynamic Response of Spar Wind Turbine Moored by Dynamic Catenaries Under Random Wind and Wave Loads

2019 ◽  
Author(s):  
Yilun Li ◽  
Shuangxi Guo ◽  
Yue Kong ◽  
Weimin Chen ◽  
Min Li
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Integrated System ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Flexible Beam ◽  
Wave Loads ◽  
Wave Load ◽  
Floating Wind Turbine

Abstract As offshore wind turbine is developed toward larger water depth, the dynamics coming from structural and fluid inertia and damping effects of the mooring-line gets more obvious, that makes the response analysis of the large floating wind turbine under wind&wave load more challenging. In this study, the dynamic response of a spar floating wind turbine under random wind and wave loads is examined by the modified FEM simulations. Here an integrated system including flexible multi-bodies such as blades, tower, spar and mooring-lines is considered while the catenary dynamics is involved. The dynamic restoring performance of the catenary mooring-line is analyzed based on the vector equations of 3D curved flexible beam and its numerical simulations. Then the structural responses, e.g. the top tension, structural displacements and stress of the tower and the blade, undergoing random wind&wave loads, are examined. Morevoer, the influences of the catenary dynamics on its restoring performance and the hysteresis behavior are presented. Our numerical results show: the dynamics of mooring-line may significantly increase the top tension, and, particularly, the snap tension could be more than 3 times larger than the quasi-static one. Moreover, the structural response under random wind&wave load gets smaller mainly because of the hysteresis effect coming from the mooring-line dynamics. The floating body displacement at surge frequency is around 20% smaller, and the tower root stress at bending frequency is about 30% smaller than the quasi-static values respectively.

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