Effect of Nacelle Drag on the Performance of a Floating Wind Turbine Platform

2019 ◽  
Author(s):  
Daewoong Son ◽  
Pauline Louazel ◽  
Bingbin Yu
Keyword(s):  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Simulation Tool ◽  
Floating Structure ◽  
Drag Forces ◽  
Floating Wind Turbine

Abstract Wind forces acting on an offshore wind turbine are transferred to the bottom of the tower and consequently to the floating structure. Thus, drag forces acting on each component of the wind turbine such as the blades, the nacelle, and the tower must be accounted for properly in order to evaluate the performance of the supporting platform. In the aero-elastic wind turbine simulation tool FAST v.7, the nacelle drag component, however, has not been implemented, which means that only the drag forces on the tower and on the blades are represented. In this work, the front and side nacelle drag forces are modelled in FAST v.7 via different drag contributions. This paper will examine the behavior of a floating offshore semisubmersible platform, the WindFloat, for different Rotor-Nacelle-Assembly (RNA) yaw-misalignments with emphasis on the nacelle drag component.

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

scholarly journals Mooring Line Damping Estimation for a Floating Wind Turbine

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Dongsheng Qiao ◽  
Jinping Ou
Keyword(s):  
Wind Turbine ◽  
Estimation Method ◽  
Excitation Amplitude ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Scale Model ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Floating Wind Turbine ◽  
Excitation Period

The dynamic responses of mooring line serve important functions in the station keeping of a floating wind turbine (FWT). Mooring line damping significantly influences the global motions of a FWT. This study investigates the estimation of mooring line damping on the basis of the National Renewable Energy Laboratory 5 MW offshore wind turbine model that is mounted on the ITI Energy barge. A numerical estimation method is derived from the energy absorption of a mooring line resulting from FWT motion. The method is validated by performing a 1/80 scale model test. Different parameter changes are analyzed for mooring line damping induced by horizontal and vertical motions. These parameters include excitation amplitude, excitation period, and drag coefficient. Results suggest that mooring line damping must be carefully considered in the FWT design.

Simulation of an Offshore Wind Turbine Using a Weakly-Compressible CFD Solver Coupled With a Blade Element Turbine Model

2019 ◽  
Author(s):  
Baptiste Elie ◽  
Guillaume Oger ◽  
David Le Touzé
Keyword(s):  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Simulation Tool ◽  
Weakly Compressible ◽  
Element Simulation ◽  
Development And Validation ◽  
Elastic Modules ◽  
Turbine Model ◽  
Blade Element

Abstract The present study addresses the first steps of development and validation of a coupled CFD-BE (Blade Element) simulation tool dedicated to offshore wind turbine farm modelling. The CFD part is performed using a weakly-compressible solver (WCCH). The turbine is taken into account using FAST (from NREL) and its effects are imposed into the fluid domain through an actuator line model. The first part of this paper is dedicated to the presentation of the WCCH solver and its coupling with the aero-elastic modules from FAST. In a second part, for validation purposes, comparisons between FAST and the WCCH-FAST coupling are presented and discussed. Finally, a discussion on the performances, advantages and limitations of the formulation proposed is provided.

Parametric Study of Catenary Mooring System for a Semisubmersible Floating Wind Turbine in Intermediate Water Depth

2020 ◽  
Author(s):  
Jiawen Li ◽  
Qiang Zhang ◽  
Jiali Du ◽  
Yichen Jiang
Keyword(s):  
Wind Turbine ◽  
Water Depth ◽  
Offshore Wind ◽  
Design Parameters ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Reference Structure ◽  
Intermediate Water ◽  
Mooring System ◽  
Floating Wind Turbine

Abstract This paper presents a parametric design study of the mooring system for a floating offshore wind turbine. We selected the OC4 DeepCwind semisubmersible floating wind turbine as the reference structure. The design water depth was 50 m, which was the transition area between the shallow and deep waters. For the floating wind turbine working in this water area, the restoring forces and moments provided by the mooring lines were significantly affected by the heave motion amplitude of the platform. Thus, the mooring design for the wind turbine in this working depth was different from the deep-water catenary mooring system. In this study, the chosen design parameters were declination angle, fairlead position, mooring line length, environmental load direction, and mooring line number. We conducted fully coupled aero-hydro dynamic simulations of the floating wind turbine system in the time domain to investigate the influences of different mooring configurations on the platform motion and the mooring tension. We evaluated both survival and accidental conditions to analyze the mooring safety under typhoon and mooring fail conditions. On the basis of the simulation results, this study made several design recommendations for the mooring configuration for floating wind turbines in intermediate water depth applied in China.

Dynamic Response of Spar-Type Floating Offshore Wind Turbine in Freak Wave

2019 ◽  
Author(s):  
Yougang Tang ◽  
Yan Li ◽  
Peng Xie ◽  
Xiaoqi Qu ◽  
Bin Wang
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Modulation Method ◽  
Power Coefficient ◽  
Offshore Wind Turbine ◽  
Floating Structure ◽  
Mooring Lines ◽  
Freak Wave ◽  
Floating Offshore Wind Turbine

Abstract Simulations are conducted in time domain to investigate the dynamic response of a SPAR-type floating offshore wind turbine under the scenarios with freak wave. Towards this end, a coupled aero-hydro numerical model is developed. The methodology includes a blade-element-momentum model for aerodynamics, a nonlinear model for hydrodynamics, a nonlinear restoring model of SPAR buoy, and a nonlinear algorithm for mooring cables. The OC3 Hywind SPAR-type FOWT is chosen as an example to study the dynamic response under the freak conditions, while the time series of freak wave is generated by the Random Frequency Components Selection Phase Modulation Method. The motions of platform, the tensions in the mooring lines and the power generation performance are documented in different cases. According to the simulations, it shows that the power coefficient of wind turbine decreased rapidly at the moment when freak wave acted on the floating structure.

scholarly journals Study of Floating Wind Turbine with Modified Tension Leg Platform Placed in Regular Waves

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 703 ◽  
Author(s):  
Juhun Song ◽  
Hee-Chang Lim
Keyword(s):  
Wind Turbine ◽  
Real Data ◽  
Offshore Wind ◽  
Scale Model ◽  
Offshore Wind Turbine ◽  
Wave Loads ◽  
Tension Leg Platform ◽  
Mooring Lines ◽  
Floating Wind Turbine ◽  
Wave Conditions

In this study, the typical ocean environment was simulated with the aim to investigate the dynamic response under various environmental conditions of a Tension Leg Platform (TLP) type floating offshore wind turbine system. By applying Froude scaling, a scale model with a scale of 1:200 was designed and model experiments were carried out in a lab-scale wave flume that generated regular periodic waves by means of a piston-type wave generator while a wave absorber dissipated wave energy on the other side of the channel. The model was designed and manufactured based on the standard prototype of the National Renewable Energy Laboratory (NREL) 5 MW offshore wind turbine. In the first half of the study, the motion and structural responses for operational wave conditions of the North Sea near Scotland were considered to investigate the performance of a traditional TLP floating wind turbine compared with that of a newly designed TLP with added mooring lines. The new mooring lines were attached with the objective of increasing the horizontal stiffness of the system and thereby reducing the dominant motion of the TLP platform (i.e., the surge motion). The results of surge translational motions were obtained both in the frequency domain, using the response amplitude operator (RAO), and in the time domain, using the omega arithmetic method for the relative velocity. The results obtained show that our suggested concept improves the stability of the platform and reduces the overall motion of the system in all degrees-of-freedom. Moreover, the modified design was verified to enable operation in extreme wave conditions based on real data for a 100-year return period of the Northern Sea of California. The loads applied by the waves on the structure were also measured experimentally using modified Morison equation—the formula most frequently used to estimate wave-induced forces on offshore floating structures. The corresponding results obtained show that the wave loads applied on the new design TLP had less amplitude than the initial model and confirmed the significant contribution of the mooring lines in improving the performance of the system.

VolturnUS 1:8: Conclusion of 18-Months of Operation of the First Grid-Connected Floating Wind Turbine Prototype in the Americas

2015 ◽  
Author(s):  
Anthony M. Viselli ◽  
Andrew J. Goupee ◽  
Habib J. Dagher ◽  
Christopher K. Allen
Keyword(s):  
Wind Turbine ◽  
Large Data ◽  
Full Scale ◽  
Offshore Wind ◽  
Mooring Line ◽  
Offshore Wind Turbine ◽  
Data Set ◽  
Floating Offshore Wind Turbine ◽  
The Past ◽  
Floating Wind Turbine

This paper presents an overview of the successful conclusion of 18 months of testing the first grid-connected floating offshore wind turbine prototype in the Americas. The prototype, called VolturnUS 1:8, was installed off Castine, Maine, USA. The prototype is a 1:8 scale prototype and serves to de-risk the deployment of a full-scale 6MW turbine. VolturnUS utilizes innovations in materials, construction, and deployment technologies such as a concrete semi-submersible hull and an advanced composite tower to reduce the costs of offshore wind. The prototype unit was designed following the American Bureau of Shipping (ABS) “Guide for Building and Classing Floating Offshore Wind Turbine Installations”. Froude scaling was used in designing the 1:8-scale VolturnUS prototype so that the motions of the prototype in the relatively protected site represent those of the full-scale unit in an open site farther offshore. During the past year, a comprehensive instrumentation package monitored key performance characteristics of the platform during operational, extreme, and survival storm conditions. Data collected include: wind speed, turbine power, rotor angular frequency, blade pitch, torque, acceleration; tower bending moment, 6 DOF accelerations at tower top and base, mooring line tensions, and wave elevation at the platform. During the past year the prototype has experienced many environments representative of scaled ABS design conditions including operational wind and sea-states, 50-year sea states and 500-year survival sea states. This large data set provides a unique view of a near full-scale floating wind turbine subjected to its prescribed environmental conditions. Inspections of the concrete hull following removal provided confirmation of material durability. Marine growth measurements provide data for future design efforts.

scholarly journals FUNDAMENTAL WIND TUNNEL EXPERIMENTS ON WIND DRAG FORCES AND DAMPINGS OF AN OFFSHORE WIND TURBINE STRUCTURE

2002 ◽  
Vol 18 ◽  
pp. 725-730
Author(s):  
Kinji SEKITA ◽  
Tatsuki HAYASHI ◽  
Hirokazu ISHIKAWA ◽  
Atsushi YAMASHITA ◽  
Nobuyuki Hayashi ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wind Tunnel Experiments ◽  
Drag Forces

scholarly journals Large Aeroelastic Model of a Floating Offshore Wind Turbine: Mechanical and Mechatronics Design

2019 ◽  
Author(s):  
Sara Muggiasca ◽  
Alessandro Fontanella ◽  
Federico Taruffi ◽  
Hermes Giberti ◽  
Alan Facchinetti ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Ocean Engineering ◽  
Floating Structure ◽  
Aeroelastic Model ◽  
Blue Growth ◽  
Turbine Model ◽  
The Eu

Abstract This paper deals with the mechatronic design of a large-scale wind turbine model (outdoor scaled prototype) based on the DTU 10MW. This is going to be integrated in the model of a multi-purpose floating structure to be deployed at the Natural Ocean Engineering Laboratory (NOEL) in Reggio Calabria (Italy). The floating wind turbine model is the downscaling of the full-scale structure designed within the EU H2020 Blue Growth Farm project. The structural design of the scaled wind turbine is presented, starting from the aeroelastic and aerodynamic design carried out in a previous work.

scholarly journals Design Methodology for a Floating Offshore Wind Turbine Large-Scale Outdoor Prototype

2019 ◽  
Author(s):  
Alessandro Fontanella ◽  
Federico Taruffi ◽  
Sara Muggiasca ◽  
Marco Belloli
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Offshore Wind ◽  
Elastic Response ◽  
Offshore Wind Turbine ◽  
Ocean Engineering ◽  
Floating Structure ◽  
Blue Growth ◽  
Turbine Model ◽  
Model Rotor

Abstract This paper discusses the methodology introduced by the authors to design a large-scale wind turbine model starting from the DTU 10MW RWT. The wind turbine will be coupled with the model of a multi-purpose floating structure, designed within the EU H2020 Blue Growth Farm project, and it will be deployed at the Natural Ocean Engineering Laboratory (NOEL). In this paper the different strategies used to design the wind turbine model rotor, tower and nacelle are discussed, focusing on how it has been possible to reproduce the full-scale system aero-elastic response while ensuring the same functionalities of a real wind turbine.

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