Stochastic dynamic response analysis of a tension leg spar-type offshore wind turbine

Wind Energy ◽  
2012 ◽  
Vol 16 (6) ◽  
pp. 953-973 ◽  
Author(s):  
Madjid Karimirad ◽  
Torgeir Moan
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Stochastic Dynamic ◽  
Dynamic Response Analysis

Dynamic Response Analysis of a Floating Offshore Wind Turbine During Severe Typhoon Event

2013 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Iku Sato ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Floating Offshore Wind Turbine ◽  
Demonstration Experiment ◽  
Typhoon Event

In this paper, dynamic response analysis of a Floating Offshore Wind Turbine (FOWT) with Spar-type floating foundation is presented. The FOWT mounts a 100kW down-wind turbine, and is grid-connected. It was launched at sea on 9th June 2012, and moored on 11th for the purpose of the demonstration experiment. During the experiment, the FOWT was attacked by severe typhoon events twice. Among them, Sanba (international designation: 1216) was the strongest tropical cyclone worldwide in 2012. The central atmospheric pressure was 940 hPa when it was close to the FOWT, and the maximum significant wave height of 9.5m was recorded at the site. In this paper, the dynamic responses of the platform motion, the stresses at the tower sections and the chain tensions during the typhoon event, Sanba (1216), have been analyzed, and compared with the measured data. Through the comparison, validation of the numerical simulation tool (Adams with SparDyn developed by the authors) has been made.

scholarly journals Stochastic Dynamic Analysis of an Offshore Wind Turbine Structure by the Path Integration Method

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3051
Author(s):  
Yue Zhao ◽  
Jijian Lian ◽  
Chong Lian ◽  
Xiaofeng Dong ◽  
Haijun Wang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Wind Turbine ◽  
Path Integration ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Stochastic Dynamic ◽  
Pi Method ◽  
Sdof System ◽  
Stochastic Dynamic Analysis

Stochastic dynamic analysis of an offshore wind turbine (OWT) structure plays an important role in the structural safety evaluation and reliability assessment of the structure. In this paper, the OWT structure is simplified as a linear single-degree-of-freedom (SDOF) system and the corresponding joint probability density function (PDF) of the dynamic response is calculated by the implementation of the path integration (PI) method. Filtered Gaussian white noise, which is obtained from the utilization of a second-order filter, is considered as horizontal wind excitation and used to excite the SDOF system. Thus, the SDOF model and the second-order linear filter model constitute a four-dimensional dynamic system. Further, a detailed three-dimensional finite element model is applied to obtain the natural frequency of the OWT and the efficient PI method, which is modified based on the fast Fourier transform (FFT) convolution method, is also utilized to reduce the execution time to obtain the PDF of the response. Two important parameters of wind conditions, i.e., horizontal mean wind speed and turbulence standard deviation, are investigated to highlight the influences on the PDF of the dynamic response and the reliability of the OWT.

scholarly journals Dynamic Response Analysis on the Interaction Between Flexible Bodies of Large-Sized Wind Turbine Under Random Wind Loads

2018 ◽  
Author(s):  
Yilun Li ◽  
Shuangxi Guo ◽  
Min Li ◽  
Weimin Chen ◽  
Yue Kong
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Elastic Deformation ◽  
Dynamic Interaction ◽  
Response Analysis ◽  
Flexible Bodies ◽  
Dynamic Response Analysis ◽  
Dynamic Behaviors ◽  
Energy Consuming ◽  
Turbine Model

As the output power of wind turbine increasingly gets larger, the structural flexibility of elastic bodies, such as rotor blades and tower, gets more significant owing to larger structural size. In that case, the dynamic interaction between these flexible bodies become more profound and may significantly impact the dynamic response of the whole wind turbine. In this study, the integrated model of a 5-MW wind turbine is developed based on the finite element simulations so as to carry out dynamic response analysis under random wind load, in terms of both time history and frequency spectrum, considering the interactions between the flexible bodies. And, the load evolution along its transmitting route and mechanical energy distribution during the dynamic response are examined. And, the influence of the stiffness and motion of the supporting tower on the integrated system is discussed. The basic dynamic characteristics and responses of 3 models, i.e. the integrated wind turbine model, a simplified turbine model (blades, hub and nacelle are simplified as lumped masses) and a rigid supported blade, are examined, and their results are compared in both time and frequency domains. Based on our numerical simulations, the dynamic coupling mechanism are explained in terms of the load transmission and energy consumption. It is found that the dynamic interaction between flexible bodies is profound for wind turbine with large structural size, e.g. the load and displacement of the tower top gets around 15% larger mainly due to the elastic deformation and dynamic behaviors (called inertial-elastic effect here) of the flexible blade; On the other hand, the elastic deformation may additionally consume around 10% energy (called energy-consuming effect) coming from external wind load and consequently decreases the displacement of the tower. In other words, there is a competition between the energy-consuming effect and inertial-elastic effect of the flexible blade on the overall dynamic response of the wind turbine. And similarly, the displacement of the blade gets up to 20% larger because the elastic-dynamic behaviors of the tower principally provides a elastic and moving support which can significantly change the natural mode shape of the integrated wind turbine and decrease the natural frequency of the rotor blade.

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