TELWIND: Numerical Analysis of a Floating Wind Turbine Supported by a Two Bodies Platform

2018 ◽  
Author(s):  
José A. Armesto ◽  
Alfonso Jurado ◽  
Raúl Guanche ◽  
Bernardino Couñago ◽  
Joaquin Urbano ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Large Scale ◽  
Ad Hoc ◽  
Numerical Study ◽  
Coupled Model ◽  
Ocean Basin ◽  
Full Description ◽  
Aerodynamic Model ◽  
Floating Wind Turbine

This paper presents a numerical study of an innovative floating wind turbine developed by ESTEYCO S.A.P. as part of an intensive R&D roadmap initiated ten years ago. The concept is called TELWIND, an evolved spar concept composed by a telescopic tower and two independent concrete bodies: the upper tank (acting as buoyancy body) and lower tank (acting as ballasting body), connected by suspension tendons. An ad-hoc numerical model has been developed by IHCantabria, calibrated and validated, based on a set of large scale laboratory tests performed at the Cantabria Coastal and Ocean Basin (CCOB), located at IHCantabria, Santander, Spain. The inhouse numerical model is a fully coupled model which comprehends three main modules: i) Hydrodynamic model that analyses the coupled hydrodynamics of floater and ballast. ii) Mooring and tendon module, and iii) Aerodynamic model. The full description of the numerical model is summarized, as well as the validation procedure followed. Finally, the validation of the numerical model is shown.

Individual Pitch Regulation for Wind Turbine

2011 ◽  
Vol 383-390 ◽  
pp. 4341-4345 ◽  
Author(s):  
Xing Jia Yao ◽  
Huan Li
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Linear Time ◽  
Coupled Model ◽  
Pitch Control ◽  
Aerodynamic Model ◽  
Multiple Variables ◽  
Individual Pitch Control ◽  
Yaw Moment

In order to reduce the tilt moment and yaw moment caused by asymmetric wind, aerodynamic model for individual pitch control of large-scale wind turbines was established. Because the aerodynamic model have characteristics of multiple variables, strong coupling and time-varying, First, it was converted into a linear time-invariant and non-coupled model utilizing a coordinate transformation, and so the controller design was simplified. Finally, take wind shearing as a disturbance and designed two independent PID controllers, simulated a 1.5MW wind turbines. The results show that individual pitch control greatly reduced the moment and yaw moment of wind turbine.

Calibration of a Time-Domain Hydrodynamic Model for A 12 MW Semi-Submersible Floating Wind Turbine

2021 ◽  
Author(s):  
Carlos Eduardo Silva de Souza ◽  
Nuno Fonseca ◽  
Petter Andreas Berthelsen ◽  
Maxime Thys
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Time Domain ◽  
Quadratic Model ◽  
Wave Loads ◽  
Frequency Wave ◽  
Load Models ◽  
Wave Drift ◽  
Floating Wind Turbine ◽  
Decay Tests

Abstract Design optimization of mooring systems is an important step towards the reduction of costs for the floating wind turbine (FWT) industry. Accurate prediction of slowly-varying horizontal motions is needed, but there are still questions regarding the most adequate models for low-frequency wave excitation, and damping, for typical FWT concepts. To fill this gap, it is fundamental to compare existing load models against model tests results. This paper describes a calibration procedure for a three-columns semi-submersible FWT, based on adjustment of a time-domain numerical model to experimental results in decay tests, and tests in waves. First, the numerical model and underlying assumptions are introduced. The model is then validated against experimental data, such that the adequate load models are chosen and adjusted. In this step, Newman’s approximation is adopted for the second-order wave loads, using wave drift coefficients obtained from the experiments. Calm-water viscous damping is represented as a linear and quadratic model, and adjusted based on decay tests. Additional damping from waves is then adjusted for each sea state, consisting of a combination of a wave drift damping component, and one component with viscous nature. Finally, a parameterization procedure is proposed for generalizing the results to sea states not considered in the tests.

The Current Situation and Recent Advances of Deep-Water Floating Wind Turbine

2012 ◽  
Vol 226-228 ◽  
pp. 772-775
Author(s):  
Yu Chen ◽  
Chun Li ◽  
Wei Gao ◽  
Jia Bin Nie
Keyword(s):  
Wind Turbine ◽  
Deep Water ◽  
Rapid Development ◽  
Coupled Model ◽  
Wind Farms ◽  
International Standards ◽  
Offshore Wind ◽  
Current Status ◽  
Offshore Wind Turbine ◽  
Floating Wind Turbine

Offshore wind turbine is a novel approach in the field of wind energy technology. With the rapid development of coastal wind farms, it is the trend to move them outward to deep-water district. However, the cost of construction rises significantly with the increase in water depth. Floating wind turbine is one of the efficient methods to solve this problem. The early history, current status and cutting-edge improvements of overseas offshore floating wind turbine as well as the shortcomings shall be presented. The concept designs, international standards, fully coupled model simulations and hydrodynamic experiments will be illustrated and discussed together with the development of the theory and the related software modules. Thus a novel researching method and concept shall be presented to provide reference for future researches

Global Analysis of a Floating Wind Turbine Using an Aero-Hydro-Elastic Numerical Model: Part 2—Benchmark Study

2011 ◽  
Author(s):  
Neil Luxcey ◽  
Harald Ormberg ◽  
Elizabeth Passano
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Global Analysis ◽  
Weather Conditions ◽  
Irregular Waves ◽  
Benchmark Study ◽  
Floating Wind Turbine ◽  
Calm Water ◽  
Internal Forces ◽  
System Power

This paper describes and presents the results of a benchmark study of a floating wind turbine numerical model that includes aero- and hydro-elasticity. The modelled wind turbine is the NREL offshore 5 MW baseline wind turbine whose specifications are publicly available. The first part of this paper demonstrates the importance of including aeroelasticity and hydroelasticity in the system. Power production, internal forces and motion amplitudes are compared to results from models using a rigid tower and rigid blades. Comparisons are performed for different weather conditions such as calm water, regular and irregular waves, constant and varying wind. The consequences of including elasticity in the different parts of the model are studied. The second part of the paper presents a benchmark study against the codes of the Offshore Code Comparison Collaboration. The floater motions, blade and tower deflection and power generation are presented and discussed.

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.

Assessing the Impact of Integrating Energy Storage on the Dynamic Response of a Spar-Type Floating Wind Turbine

2019 ◽  
Author(s):  
Charise Cutajar ◽  
Tonio Sant ◽  
Robert N. Farrugia ◽  
Daniel Buhagiar
Keyword(s):  
Energy Storage ◽  
Dynamic Response ◽  
Wind Turbine ◽  
Energy Demand ◽  
Large Scale ◽  
Preliminary Investigation ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Floating Wind Turbine ◽  
The Impact

Abstract Offshore wind technology is at the forefront of exploiting renewable energy at sea. The latest innovations in the field comprise floating wind turbines deployed in deep waters that are capable of intercepting the stronger, less turbulent winds farther away from the landmass. Despite being able to augment the power harnessed, wind resources remain intermittent in nature, and so unable to satisfy the energy demand at all times. Energy storage systems (ESS) are therefore being considered a key component to smoothen out the supply-demand mismatch when wind penetration into electricity grids increases. Yet, multiple issues pertaining to the integration of ESSs on large-scale projects arise, including economic, environmental and safety considerations. This paper presents a novel concept for integrating a hydro-pneumatic energy storage (HPES) system within a spar-type floating offshore wind turbine (FOWT) platform. It aims to assess the technical feasibility of integrating the storage unit within the floater. A preliminary investigation on the influence of integrated storage on the static stability and hydrostatic response of a conventional ballast-stabilised FOWT is conducted, followed by numerical simulations for the dynamic response using ANSYS® AQWA™. Based on the results presented, several conclusions are drawn on the implications of integrating energy storage with floating wind turbine structures. Finally, a preliminary assessment of the thermal efficiency of the storage system based on this specific embodiment is also presented and discussed.

scholarly journals Interaction between Crustal-Scale Darcy and Hydrofracture Fluid Transport: A Numerical Study

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Tamara de Riese ◽  
Paul D. Bons ◽  
Enrique Gomez-Rivas ◽  
Till Sachau
Keyword(s):  
Fluid Flow ◽  
Numerical Model ◽  
Transport Mechanism ◽  
Large Scale ◽  
Fluid Transport ◽  
Numerical Study ◽  
Ballistic Transport ◽  
Accretionary Prism ◽  
Small Scale ◽  
Porous Flow

Crustal-scale fluid flow can be regarded as a bimodal transport mechanism. At low hydraulic head gradients, fluid flow through rock porosity is slow and can be described as diffusional. Structures such as hydraulic breccias and hydrothermal veins both form when fluid velocities and pressures are high, which can be achieved by localized fluid transport in space and time, via hydrofractures. Hydrofracture propagation and simultaneous fluid flow can be regarded as a “ballistic” transport mechanism, which is activated when transport by diffusion alone is insufficient to release the local fluid overpressure. The activation of a ballistic system locally reduces the driving force, through allowing the escape of fluid. We use a numerical model to investigate the properties of the two transport modes in general and the transition between them in particular. We developed a numerical model in order to study patterns that result from bimodal transport. When hydrofractures are activated due to low permeability relative to fluid flux, many hydrofractures form that do not extend through the whole system. These abundant hydrofractures follow a power-law size distribution. A Hurst factor of ~0.9 indicates that the system self-organizes. The abundant small-scale hydrofractures organize the formation of large-scale hydrofractures that ascend through the whole system and drain fluids in large bursts. As the relative contribution of porous flow increases, escaping fluid bursts become less frequent, but more regular in time and larger in volume. We propose that metamorphic rocks with abundant veins, such as in the Kodiak accretionary prism (Alaska) and Otago schists (New Zealand), represent regions with abundant hydrofractures near the fluid source, while hydrothermal breccias are formed by the large fluid bursts that can ascend the crust to shallower levels.

Numerical Design of a Floating Offshore Wind Turbine Large Scale Model for Control Purposes

2021 ◽  
Author(s):  
Federico Taruffi ◽  
Simone Di Carlo ◽  
Sara Muggiasca ◽  
Alessandro Fontanella
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Large Scale ◽  
Offshore Wind ◽  
Scale Model ◽  
Offshore Wind Turbine ◽  
Floating Platform ◽  
Floating Offshore Wind Turbine ◽  
Numerical Design ◽  
Blue Growth

Abstract This paper deals with the numerical design of a floating offshore wind turbine outdoor large-scale prototype based on the DTU 10MW. The objective of this work is to develop a numerical simulation environment for the design of an outdoor scaled prototype. The numerical model is realized coupling the preliminary designed Blue Growth Farm large-scale turbine model with a traditional floater, the OC3 spar buoy. The numerical model is used to evaluate the loads associated with the wind turbine when combined to a floating foundation, with the focus on the coupling between the dynamics of the control system and the one of the floating platform. In addition to this, also the consistency of loads on crucial turbine components is an interesting test bench for the evaluation of the dynamical effects and drives the final design of the physical model.

scholarly journals Response Characteristics of the DeepCwind Floating Wind Turbine Moored by a Single-Point Mooring System

2018 ◽  
Vol 8 (11) ◽  
pp. 2306 ◽  
Author(s):  
Yingyi Liu ◽  
Shigeo Yoshida ◽  
Hiroshi Yamamoto ◽  
Akinori Toyofuku ◽  
Guanghua He ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Numerical Study ◽  
Single Point ◽  
Offshore Wind ◽  
Response Characteristics ◽  
Floating Wind Turbine ◽  
Decay Test ◽  
Response Amplitude Operators ◽  
Marine Engineering ◽  
Offshore Oil

In recent years, the SPM (Single-Point Mooring) concept has been widely employed in several branches of the naval architecture and marine engineering field, such as FPSOs (Floating Production, Storage and Offloading units), offshore oil rigs, etc., but not yet popular in the offshore wind energy. To investigate the response characteristics of an SPM-moored FWT (Floating Wind Turbine), in the present work, we perform a numerical study on the DeepCwind semisubmersible wind turbine, using the state-of-the-art open-source tool FAST. The free-decay test results show that the SPM layout affects the natural periods of the wind turbine in rotational modes, as well as the mooring stiffness of the diagonal rotational and crossing rotational-translational terms, especially in relation to the yaw mode. Comparisons of the RAOs (Response Amplitude Operators) elucidate that the presence of wind influences significantly the sway, roll and yaw motions of the SPM layout. Finally, the weathervane test shows that an asymmetry exists in the free-yaw motion response when the semisubmersible wind turbine is moored by an SPM system.

scholarly journals NUMERICAL STUDY OF WAVE RUN-UP AT PERMEABLE FIXED REVETMENT SLOPE

2017 ◽  
pp. 32
Author(s):  
Izmail Kantarzhi ◽  
Sergii Kivva ◽  
Natalia V Shunko
Keyword(s):  
Porous Medium ◽  
Numerical Model ◽  
Large Scale ◽  
Numerical Study ◽  
Water Filtration ◽  
Wave Surface ◽  
Natural Conditions ◽  
Wave Flume ◽  
Run Up ◽  
Large Scale Tests

The numerical model of wave surface elevation and water filtration in the saturated-unsaturated porous medium is developed. The model uses to define the parameters of the wave run-up at the slope protected by the permeable fixed layer. The model shows the wave surface in the different times, including the wave run-up height at the slope and wave run-down. Also, the velocities in the upper protected layer as well in the soil body of the slope are defined. Model is verified with using of the published large-scale tests with the slopes protected by Elastocoast technology layers. The tests were carried out in the wave flume of Technical University Braunschweig. The numerical model may be applied to calculate the maximal waves run-up at the protected engineering and beach slopes in natural conditions.

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