scholarly journals Dynamic Analysis Of The Mooring System For A Floating Offshore Wind Turbine Spar Platform

2015 ◽  
Author(s):  
D. P Zhang ◽  
K. Q Zhu ◽  
B. Jing ◽  
R. Z Yang ◽  
Z. C Tang
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Mooring System ◽  
Spar Platform ◽  
Floating Offshore Wind Turbine

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 Responses of a Spar Type Floating Offshore Wind Turbine With Failed Moorings

2020 ◽  
Author(s):  
Yajun Ren ◽  
Vengatesan Venugopal
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Mooring System ◽  
Floating Offshore Wind Turbine ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Platform Motions

Abstract The complex dynamic characteristics of Floating Offshore Wind Turbines (FOWTs) have raised wider consideration, as they are likely to experience harsher environments and higher instabilities than the bottom fixed offshore wind turbines. Safer design of a mooring system is critical for floating offshore wind turbine structures for station keeping. Failure of mooring lines may lead to further destruction, such as significant changes to the platform’s location and possible collisions with a neighbouring platform and eventually complete loss of the turbine structure may occur. The present study focuses on the dynamic responses of the National Renewable Energy Laboratory (NREL)’s OC3-Hywind spar type floating platform with a NREL offshore 5-MW baseline wind turbine under failed mooring conditions using the fully coupled numerical simulation tool FAST. The platform motions in surge, heave and pitch under multiple scenarios are calculated in time-domain. The results describing the FOWT motions in the form of response amplitude operators (RAOs) and spectral densities are presented and discussed in detail. The results indicate that the loss of the mooring system firstly leads to longdistance drift and changes in platform motions. The natural frequencies and the energy contents of the platform motion, the RAOs of the floating structures are affected by the mooring failure to different degrees.

Development of Floating Offshore Wind Turbine and the Mooring System

2013 ◽  
Vol 790 ◽  
pp. 634-637
Author(s):  
Xue Liang Zhao ◽  
Wei Ming Gong
Keyword(s):  
Wind Turbine ◽  
Research Work ◽  
Experimental Tests ◽  
Offshore Wind ◽  
Future Research ◽  
Offshore Wind Turbine ◽  
Mooring System ◽  
Floating Offshore Wind Turbine ◽  
Energy Demands

The offshore wind turbine, especially the floating offshore wind turbine in the deep sea is a perspective technology in the context of increasing energy demands. Mooring system, as an important unit of the floating offshore wind turbine is emphasized. The methods of in-situ test and the laboratory experimental tests are reviewed. Some new testing methods are discussed. The most commonly used anchor systems are explored. The paper aims to present some future research work that is important for the development of the floating offshore wind turbine technology.

Coupled Numerical Analysis of a Concept TLB Type Floating Offshore Wind Turbine

2019 ◽  
Author(s):  
Iman Ramzanpoor ◽  
Martin Nuernberg ◽  
Longbin Tao
Keyword(s):  
Wind Turbine ◽  
Renewable Energy Sources ◽  
Second Order ◽  
Offshore Wind ◽  
Design Stage ◽  
Offshore Wind Turbine ◽  
Clear Understanding ◽  
Mooring System ◽  
Floating Platform ◽  
Floating Offshore Wind Turbine

Abstract The main drivers for the continued decarbonisation of the global energy market are renewable energy sources. Moreover, the leading technological solutions to achieve this are offshore wind turbines. As installed capacity has been increasing rapidly and shallow water near shore sites are exhausted, projects will need to be developed further from shore and often in deeper waters, which will pose greater technical challenges and constrain efforts to reduce costs. Current floating platform solutions such as the spar and semi-submersible rely on large amounts of ballast and complex structural designs with active stabilisation systems for stability of the floating offshore wind turbine platform (FOWT). The primary focus of this study is to present a design concept and mooring arrangement for an alternative floating platform solution that places emphasis on the mooring system to achieve stability for a FOWT. The tension leg buoy (TLB) is designed to support future 10MW offshore wind turbine generators. This paper presents the numerical methodology used for a coupled hydro-elastic analysis of the floater and mooring system under combined wind, wave and current effects. A concept TLB design is presented and its platform motion and mooring line tension characteristics are analysed for a three-hour time domain simulation representing operating and survival conditions in the northern North Sea with water depths of 110 metres. The importance of wave drift forces and the other non-linear excitation forces in the concept design stage are evaluated by comparing the motion and tension responses of three different numerical simulation cases with increasing numerical complexity. The preliminary TLB system design demonstrated satisfactory motion response for the operation of a FOWT and survival in a 100-year storm condition. The results show that accounting for second-order effect is vital in terms of having a clear understanding of the full behaviour of the system and the detailed response characteristics in operational and survival conditions. Extreme loads are significantly reduced when accounting for the second-order effects. This can be a key aspect to not overdesign the system and consequently achieve significant cost savings.

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.

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