Dynamic Analysis of a Floating Offshore Wind Turbine Under Extreme Environmental Conditions

2012 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Iku Sato ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Environmental Conditions ◽  
Aerodynamic Force ◽  
Experimental Results ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Analysis Tool ◽  
Simulation Code ◽  
Floating Offshore Wind Turbine

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.

Dynamic Analysis of a Floating Offshore Wind Turbine Under Extreme Environmental Conditions

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Iku Sato ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Environmental Conditions ◽  
Aerodynamic Force ◽  
Cross Flow ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Analysis Tool ◽  
Simulation Code ◽  
Floating Offshore Wind Turbine

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 multibody 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. In this paper, only parked conditions are considered. The comparison shows that the principal behavior of the floating offshore wind turbine with spar platform has been captured by the developed program. However, when vortex-induced motion (VIM) 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.

scholarly journals Numerical Validation of Floating Offshore Wind Turbine Scaled Rotors for Surge Motion

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2578 ◽  
Author(s):  
Krishnamoorthi Sivalingam ◽  
Steven Martin ◽  
Abdulqadir Singapore Wala
Keyword(s):  
Wind Turbine ◽  
Turbine Rotor ◽  
Power Converter ◽  
Experimental Results ◽  
Offshore Wind ◽  
Speed Ratio ◽  
Offshore Wind Turbine ◽  
Floating Offshore Wind Turbine ◽  
Aerodynamic Loads ◽  
Unsteady Aerodynamic

Aerodynamic performance of a floating offshore wind turbine (FOWT) is significantly influenced by platform surging motions. Accurate prediction of the unsteady aerodynamic loads is imperative for determining the fatigue life, ultimate loads on key components such as FOWT rotor blades, gearbox and power converter. The current study examines the predictions of numerical codes by comparing with unsteady experimental results of a scaled floating wind turbine rotor. The influence of platform surge amplitude together with the tip speed ratio on the unsteady aerodynamic loading has been simulated through unsteady CFD. It is shown that the unsteady aerodynamic loads of FOWT are highly sensitive to the changes in frequency and amplitude of the platform motion. Also, the surging motion significantly influences the windmill operating state due to strong flow interaction between the rotating blades and generated blade-tip vortices. Almost in all frequencies and amplitudes, CFD, LR-BEM and LR-uBEM predictions of mean thrust shows a good correlation with experimental results.

Global Responses and Loads Analysis of a 750-kW Semi-Submersible Floating Offshore Wind Turbine Under Extreme Environmental Conditions

2019 ◽  
Author(s):  
Thanh Dam Pham ◽  
Junbae Kim ◽  
Byoungcheon Seo ◽  
Rupesh Kumar ◽  
Youngjae Yu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Environmental Conditions ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
East Sea ◽  
Offshore Wind Turbine ◽  
Test Model ◽  
Scaled Model ◽  
Floating Offshore Wind Turbine ◽  
Extreme Loads

Abstract A pilot floating offshore wind turbine project of Korea was proposed for installing in the East Sea of Korea. The prototype is a semisubmersible platform supporting a 750-kW wind turbine. A scaled model was tested in the basin tank of the University of Ulsan at scale ratio 1:40. The 750-kW floating offshore wind turbine was modeled by using the NREL-FAST code. Numerical results were validated by comparing with those of the test model. This paper analyzes dynamic responses and loads of the wind turbine system under extreme environmental conditions. Extreme environmental conditions based on metocean data of East Sea Korea. Extreme responses and extreme loads are important data for designing the structure of the 750 kW semi-submersible floating offshore wind turbine.

Coupled Dynamic Analysis of a Tension Leg Platform Floating Offshore Wind Turbine

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Teng Wang ◽  
Hui Jin ◽  
Xiaoni Wu
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Wind Loads ◽  
Offshore Wind Turbine ◽  
Wave Loads ◽  
Tension Leg Platform ◽  
Floating Offshore Wind Turbine ◽  
Turbulent Wind ◽  
Coupled Dynamic Analysis

The dynamic response of a tension leg platform (TLP) floating offshore wind turbine (FOWT) was analyzed with considering the aero-hydro characteristic of the whole floating wind turbine system including the wind turbine, TLP platform, and tethers. The “aero-hydro” coupled dynamic analysis was conducted in ansys-aqwa with a dynamic link library (DLL) calculating the aerodynamics loading at every steptime based on the blade element momentum theory. Results from the coupled dynamic analysis of TLP FOWT under the condition of turbulent wind and regular wave show that the wind loads influence mainly the low-frequency response of the TLP FOWT. The wind loads have a large impact on the offsets of the TLP away from the initial position while the wave loads influence mainly the fluctuation amplitude of the TLP FOWT. The average TLP pitch response under the wind load is significantly larger due to the large wind-induced heeling moment on the wind turbine. In addition, the tension of tethers at the upwind end is greater than that at the downwind end. The wind loads could reduce effectively the average tension of the tethers, and the tension of tethers is significantly affected by the pitch motion. Results from the coupled dynamic analysis of TLP FOWT under the condition of turbulent wind and irregular wave show that the surge and pitch of TLP result in an obvious increase of thrust of the turbine and the amplitude of torque fluctuation, more attention should be paid to the pitch and surge motion of TLP FOWT.

Investigation on High-Order Coupled Rigid-Flexible Multi-Body Dynamic Code for Offshore Floating Wind Turbines

2017 ◽  
Author(s):  
Zhiqiang Hu ◽  
Jiahao Chen ◽  
Geliang Liu
Keyword(s):  
Wind Turbine ◽  
Coupled Model ◽  
High Order ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Mooring Lines ◽  
Simulation Code ◽  
Floating Offshore Wind Turbine ◽  
Restoring Forces ◽  
Multi Body

This paper presents a preliminary development and validation of a high-order coupled time-domain simulation code DARwind for floating offshore wind turbine systems. In the code, unsteady Blade-Element-Momentum method with some corrections has been utilized to calculate aerodynamic loads. Combination of potential-flow theory and Morison“s equation are applied to calculate hydrodynamic loads. A quasi-static catenary mooring model is used to consider restoring forces from mooring lines. Kane“s dynamic equations and a high-order coupled model with mode superposition are proposed to model kinematics and structural dynamics of floating offshore wind turbine systems. Subsequently, the effectiveness of the code and its unique high-order coupled dynamic characteristics have been verified by code-to-code tests.

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