Research on the Influence of Helical Strakes and Its Parameters on Dynamic Response of Platform of Floating Wind Turbine Based on Optimization Method of Orthogonal Design

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Qinwei Ding ◽  
Chun Li ◽  
Binxin Li ◽  
Wenxing Hao ◽  
Zhou Ye
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Orthogonal Design ◽  
Exciting Force ◽  
Design Parameters ◽  
Spar Platform ◽  
Floating Wind Turbine ◽  
Helical Strakes ◽  
Pitch Ratio ◽  
The Impact

The stability of platform is the most fundamental guarantee for the safe operation of floating wind turbine in complex marine environment. The helical strakes used on spar platform in the traditional oil industry are useful and effective. This paper is to investigative the validity of helical strakes when used for offshore wind energy harvesting. The National Renewable Energy Laboratory (NREL) 5 MW wind turbine based on OC3-Hywind spar-buoy platform with the attachment of helical strakes is modeled for the purpose to analysis the impact of helical strakes and its design parameters (number, height, and pitch ratio) on the dynamic response of the floating wind turbine spar platform. The dynamic response of spar platform under wind, wave, and current loads is calculated and analyzed based on the radiation and diffraction theory, the finite element method, and the orthogonal design method. The research result shows that the helical strakes can effectively suppress the dynamic response of the platform but enlarge the wave exciting force, and helical strakes cannot change peak frequency of response amplitude operator (RAO) and wave exciting force of spar in frequency-domain. The best parameter combination is two pieces of helical strakes with height of 15%D and the pitch ratio of 5. Height and pitch ratio of the helical strakes have significant influence on pitch response, while the number and interaction of height and pitch ratio have slight effect.

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.

Effects of heave plate on dynamic response of floating wind turbine Spar platform under the coupling effect of wind and wave

2020 ◽  
Vol 201 ◽  
pp. 107103 ◽  
Author(s):  
Minnan Yue ◽  
Qingsong Liu ◽  
Chun Li ◽  
Qinwei Ding ◽  
Shanshan Cheng ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Coupling Effect ◽  
Spar Platform ◽  
Floating Wind Turbine ◽  
Heave Plate

scholarly journals Dynamic Response of Floating Wind Turbine Under Consideration of Dynamic Behavior of Catenary Mooring-Lines

2017 ◽  
Author(s):  
Shuangxi Guo ◽  
Yilun Li ◽  
Min Li ◽  
Weimin Chen ◽  
Yiqin Fu
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Nonlinear Dynamic ◽  
Ocean Waves ◽  
Wave Frequency ◽  
Mooring Line ◽  
Mooring Lines ◽  
Restoring Force ◽  
Dynamic Behaviors ◽  
Floating Wind Turbine

Recently, wind turbine has been developed from onshore area to offshore area because of more powerful available wind energy in ocean area and more distant and less harmful noise coming from turbine. As it is approaching toward deeper water depth, the dynamic response of the large floating wind turbine experiencing various environmental loads becomes more challenge. For examples, as the structural size gets larger, the dynamic interaction between the flexible bodies such as blades, tower and catenary mooring-lines become more profound, and the dynamic behaviors such as structural inertia and hydrodynamic force of the mooring-line get more obvious. In this paper, the dynamic response of a 5MW floating wind turbine undergoing different ocean waves is examined by our FEM approach in which the dynamic behaviors of the catenary mooring-line are involved and the integrated system including flexible multi-bodies such as blades, tower, spar platform and catenaries can be considered. Firstly, the nonlinear dynamic model of the integrated wind turbine is developed. Different from the traditional static restoring force, the dynamic restoring force is analyzed based on our 3d curved flexible beam approach where the structural curvature changes with its spatial position and the time in terms of vector equations. And, the modified finite element simulation is used to model a flexible and moving catenary of which the hydrodynamic load depending on the mooring-line’s motion is considered. Then, the nonlinear dynamic governing equations is numerically solved by using Newmark-Beta method. Based on our numerical simulations, the influences of the dynamic behaviors of the catenary mooring-line on its restoring performance are presented. The dynamic responses of the floating wind turbine, e.g. the displacement of the spar and top tower and the dynamic tension of the catenary, undergoing various ocean waves, are examined. The dynamic coupling between different spar motions, i.e. surge and pitch, are discussed too. Our numerical results show: the dynamic behaviors of mooring-line may significantly increase the top tension, particularly, the peak-trough tension gap of snap tension may be more than 9 times larger than the quasi-static result. When the wave frequency is much higher than the system, the dynamic effects of the mooring system will accelerate the decay of transient items of the dynamic response; when the wave frequency and the system frequency are close to each other, the displacement of the spar significantly reduces by around 26%. Under regular wave condition, the coupling between the surge and pitch motions are not obvious; but under extreme condition, pitch motion may get about 20% smaller than that without consideration of the coupling between the surge and pitch motions.

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

Short-Term Extreme Motions of a Spar Floating Wind Turbine Estimated Through a 1:30 At-Sea Experiment

2018 ◽  
Author(s):  
Carlo Ruzzo ◽  
Nilanjan Saha ◽  
Felice Arena
Keyword(s):  
Wind Turbine ◽  
Degrees Of Freedom ◽  
Extreme Values ◽  
Model Structure ◽  
Ocean Engineering ◽  
Short Term ◽  
Spar Platform ◽  
Six Degrees Of Freedom ◽  
Floating Wind Turbine ◽  
Scale Models

The present paper deals with the estimation of the short-term extreme motions of a spar floating wind turbine in parked rotor conditions, through a 1:30 at-sea experiment, carried out at the Natural Ocean Engineering Laboratory (NOEL) of Reggio Calabria (Italy). Thanks to some favorable local environmental conditions of the site, several wind-generated sea states with relatively low significant wave height (Hs < 0.50 m) have been collected during the experiment. These sea states are scale models of ocean storms, which are relevant hydrodynamic design conditions for the spar platform. The 30-minutes extreme values of the model structure motions have been estimated for all the six degrees of freedom, using the Weibull Tail Method (WTM), and the results obtained are presented in the paper. Such estimations are 1:30 scale models of the 3-hours extreme values of the spar motions in parked rotor conditions and may be directly used for design purposes.

A Numerical Prediction on the Transient Response of a Spar-Type Floating Offshore Wind Turbine in Freak Waves

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Yan Li ◽  
Xiaoqi Qu ◽  
Liqin Liu ◽  
Peng Xie ◽  
Tianchang Yin ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Numerical Code ◽  
Modulation Method ◽  
Offshore Wind Turbine ◽  
Freak Waves ◽  
Freak Wave ◽  
Floating Offshore Wind Turbine ◽  
The Impact

Abstract Simulations are conducted in time domain to investigate the dynamic response of a spar-type floating offshore wind turbine (FOWT) under the freak wave scenarios. Toward this end, a coupled aero-hydro-mooring in-house numerical code is adopted to perform the simulations. The methodology includes a blade-element-momentum (BEM) model for simulating the aerodynamic loads, a nonlinear model for simulating the hydrodynamic loads, a nonlinear restoring model of Spar buoy, and a nonlinear algorithm for simulating the mooring cables. The OC3 Hywind spar-type FOWT is adopted as an example to study the dynamic response under the freak wave conditions, meanwhile the time series of freak waves are generated using the random frequency components selection phase modulation method. The motion of platform, the tension applied on the mooring lines, and the power generation performance are documented in several cases. According to the simulations, it is indicated that when a freak wave acts on the FOWT, the transient motion of the FOWT is induced in all degrees-of-freedom, as well as the produced power decreases rapidly. Furthermore, the impact of freak wave parameters on the motion of FOWT is discussed.

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 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.

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.

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