Coupled Dynamic Analysis of Floating Offshore Wind Farms

Download Coupled Dynamic Analysis of Floating Offshore Wind Farms PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (69 download)

DOWNLOAD NOW!


Book Synopsis Coupled Dynamic Analysis of Floating Offshore Wind Farms by : Sangyun Shim

Download or read book Coupled Dynamic Analysis of Floating Offshore Wind Farms written by Sangyun Shim and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past decade, the demand for clean renewable energy continues to rise drastically in Europe, the US, and other countries. Wind energy in the ocean can possibly be one of those future renewable clean energy sources as long it is economically feasible and technologically manageable. So far, most of the offshore wind farm research has been limited to fixed platforms in shallow-water areas. In the water depth deeper than 30m, however, floating-type wind farms tend to be more feasible. Then, the overall design and engineering becomes more complicated than fixed platforms including the coupled dynamics of platforms, mooring lines, and blades. In the present study, a numerical time-domain model has been developed for the fully coupled dynamic analysis of an offshore floating wind turbine system including blade-rotor dynamics and platform motions. As a test case, the TLP-type floater system with 3 blades of 70-m diameter designed by the National Renewable Energy Laboratory (NREL) is selected to analyze the dynamic coupling effects among floating system, mooring lines, and wind turbine. The performance of the selected system in a typical wind-wave-current condition has been simulated and analyzed. A similar study for the floater and rotor coupled dynamic analysis was conducted by MIT and NREL. However, in the present case, the dynamic coupling between platform and mooring lines are also considered in addition to the rotor-floater dynamic coupling. It is seen that the rotor-floater coupling effects increase with wind velocity and blade size. The increased coupling effects tend to increase the dynamic tension of TLP tethers. The developed technology and numerical tool are applicable to the new offshore floating wind farms planned in the future.

Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine

Download Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (868 download)

DOWNLOAD NOW!


Book Synopsis Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine by : Yoon Hyeok Bae

Download or read book Coupled Dynamic Analysis of Multiple Unit Floating Offshore Wind Turbine written by Yoon Hyeok Bae and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present study, a numerical simulation tool has been developed for the rotor-floater-tether coupled dynamic analysis of Multiple Unit Floating Offshore Wind Turbine (MUFOWT) in the time domain including aero-blade-tower dynamics and control, mooring dynamics and platform motion. In particular, the numerical tool developed in this study is based on the single turbine analysis tool FAST, which was developed by National Renewable Energy Laboratory (NREL). For linear or nonlinear hydrodynamics of floating platform and generalized-coordinate-based FEM mooring line dynamics, CHARM3D program, hull-riser-mooring coupled dynamics program developed by Prof. M.H. Kim's research group during the past two decades, is incorporated. So, the entire dynamic behavior of floating offshore wind turbine can be obtained by coupled FAST-CHARM3D in the time domain. During the coupling procedure, FAST calculates all the dynamics and control of tower and wind turbine including the platform itself, and CHARM3D feeds all the relevant forces on the platform into FAST. Then FAST computes the whole dynamics of wind turbine using the forces from CHARM3D and return the updated displacements and velocities of the platform to CHARM3D. To analyze the dynamics of MUFOWT, the coupled FAST-CHARM3D is expanded more and re-designed. The global matrix that includes one floating platform and a number of turbines is built at each time step of the simulation, and solved to obtain the entire degrees of freedom of the system. The developed MUFOWT analysis tool is able to compute any type of floating platform with various kinds of horizontal axis wind turbines (HAWT). Individual control of each turbine is also available and the different structural properties of tower and blades can be applied. The coupled dynamic analysis for the three-turbine MUFOWT and five-turbine MUFOWT are carried out and the performances of each turbine and floating platform in normal operational condition are assessed. To investigate the coupling effect between platform and each turbine, one turbine failure event is simulated and checked. The analysis shows that some of the mal-function of one turbine in MUFOWT may induce significant changes in the performance of other turbines or floating platform. The present approach can directly be applied to the development of the remote structural health monitoring system of MUFOWT in detecting partial turbine failure by measuring tower or platform responses in the future. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149465

Floating Offshore Wind Energy

Download Floating Offshore Wind Energy PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319293982
Total Pages : 345 pages
Book Rating : 4.3/5 (192 download)

DOWNLOAD NOW!


Book Synopsis Floating Offshore Wind Energy by : Joao Cruz

Download or read book Floating Offshore Wind Energy written by Joao Cruz and published by Springer. This book was released on 2016-08-20 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a state-of-the-art review of floating offshore wind turbines (FOWT). It offers developers a global perspective on floating offshore wind energy conversion technology, documenting the key challenges and practical solutions that this new industry has found to date. Drawing on a wide network of experts, it reviews the conception, early design stages, load & structural analysis and the construction of FOWT. It also presents and discusses data from pioneering projects. Written by experienced professionals from a mix of academia and industry, the content is both practical and visionary. As one of the first titles dedicated to FOWT, it is a must-have for anyone interested in offshore renewable energy conversion technologies.

Aerodynamics of Wind Turbines, 2nd edition

Download Aerodynamics of Wind Turbines, 2nd edition PDF Online Free

Author :
Publisher : Routledge
ISBN 13 : 1136572260
Total Pages : 192 pages
Book Rating : 4.1/5 (365 download)

DOWNLOAD NOW!


Book Synopsis Aerodynamics of Wind Turbines, 2nd edition by : Martin O. L. Hansen

Download or read book Aerodynamics of Wind Turbines, 2nd edition written by Martin O. L. Hansen and published by Routledge. This book was released on 2013-05-13 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural response of the wind turbine structure. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method is also covered, as are eigenmodes and the dynamic behaviour of a turbine. The new material includes a description of the effects of the dynamics and how this can be modelled in an ?aeroelastic code?, which is widely used in the design and verification of modern wind turbines. Further, the description of how to calculate the vibration of the whole construction, as well as the time varying loads, has been substantially updated.

Fully Coupled Dynamic Analysis of a Floating Wind Turbine System

Download Fully Coupled Dynamic Analysis of a Floating Wind Turbine System PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 151 pages
Book Rating : 4.:/5 (568 download)

DOWNLOAD NOW!


Book Synopsis Fully Coupled Dynamic Analysis of a Floating Wind Turbine System by : Jon E. Withee

Download or read book Fully Coupled Dynamic Analysis of a Floating Wind Turbine System written by Jon E. Withee and published by . This book was released on 2004 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of wind power is in a period of rapid growth worldwide and wind energy systems have emerged as a promising technology for utilizing offshore wind resources for the large scale generation of electricity Drawing upon the maturity of wind turbine and floater technologies developed by the wind energy and oil and gas industries, respectively, large offshore wind energy systems have been developed and are being proposed for operation in offshore areas where environmental restrictions are less restrictive, large wind resources exist, and open sea areas are available for wind farm development. A fully coupled dynamic analysis/technique was developed to predict the response of a floating wind turbine system in a stochastic wind and wave environment This technique incorporated both non-linear wave loading on the submerged floater and the aerodynamic loading on the wind turbine A tension leg spar buoy was designed to support the wind turbine This design was chosen due to its relatively small size and hence lower potential cost per wind turbine The system's tethers were attached to the ends of spokes which radiated out from the spar cylinder This arrangement of lines and spokes promised to be very stiff in the roll and pitch modes of motion.

Coupled Dynamic Modeling of Floating Wind Turbine Systems

Download Coupled Dynamic Modeling of Floating Wind Turbine Systems PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 25 pages
Book Rating : 4.:/5 (727 download)

DOWNLOAD NOW!


Book Synopsis Coupled Dynamic Modeling of Floating Wind Turbine Systems by :

Download or read book Coupled Dynamic Modeling of Floating Wind Turbine Systems written by and published by . This book was released on 2006 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: This article presents a collaborative research program that the Massachusetts Institute of Technology (MIT) and the National Renewable Energy Laboratory (NREL) have undertaken to develop innovative and cost-effective floating and mooring systems for offshore wind turbines in water depths of 10-200 m. Methods for the coupled structural, hydrodynamic, and aerodynamic analysis of floating wind turbine systems are presented in the frequency domain. This analysis was conducted by coupling the aerodynamics and structural dynamics code FAST [4] developed at NREL with the wave load and response simulation code WAMIT (Wave Analysis at MIT) [15] developed at MIT. Analysis tools were developed to consider coupled interactions between the wind turbine and the floating system. These include the gyroscopic loads of the wind turbine rotor on the tower and floater, the aerodynamic damping introduced by the wind turbine rotor, the hydrodynamic damping introduced by wave-body interactions, and the hydrodynamic forces caused by wave excitation. Analyses were conducted for two floater concepts coupled with the NREL 5-MW Offshore Baseline wind turbine in water depths of 10-200 m: the MIT/NREL Shallow Drafted Barge (SDB) and the MIT/NREL Tension Leg Platform (TLP). These concepts were chosen to represent two different methods of achieving stability to identify differences in performance and cost of the different stability methods. The static and dynamic analyses of these structures evaluate the systems' responses to wave excitation at a range of frequencies, the systems' natural frequencies, and the standard deviations of the systems' motions in each degree of freedom in various wind and wave environments. This article in various wind and wave environments. This article explores the effects of coupling the wind turbine with the floating platform, the effects of water depth, and the effects of wind speed on the systems' performance. An economic feasibility analysis of the two concepts was also performed. Key cost components included the material and construction costs of the buoy; material and installation costs of the tethers, mooring lines, and anchor technologies; costs of transporting and installing the system at the chosen site; and the cost of mounting the wind turbine to the platform. The two systems were evaluated based on their static and dynamic performance and the total system installed cost. Both systems demonstrated acceptable motions, and have estimated costs of $1.4-$1.8 million, not including the cost of the wind turbine, the power electronics, or the electrical transmission.

Offshore Mechanics

Download Offshore Mechanics PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119216621
Total Pages : 305 pages
Book Rating : 4.1/5 (192 download)

DOWNLOAD NOW!


Book Synopsis Offshore Mechanics by : Madjid Karimirad

Download or read book Offshore Mechanics written by Madjid Karimirad and published by John Wiley & Sons. This book was released on 2018-05-07 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers theoretical concepts in offshore mechanics with consideration to new applications, including offshore wind farms, ocean energy devices, aquaculture, floating bridges, and submerged tunnels This comprehensive book covers important aspects of the required analysis and design of offshore structures and systems and the fundamental background material for offshore engineering. Whereas most of the books currently available in the field use traditional oil, gas, and ship industry examples in order to explain the fundamentals in offshore mechanics, this book uses more recent applications, including recent fixed-bottom and floating offshore platforms, ocean energy structures and systems such as wind turbines, wave energy converters, tidal turbines and hybrid marine platforms. Offshore Mechanics covers traditional and more recent methodologies used in offshore structure modelling (including SPH and hydroelasticity models). It also examines numerical techniques, including computational fluid dynamics and finite element method. Additionally, the book features easy-to-understand exercises and examples. Provides a comprehensive treatment for the case of recent applications in offshore mechanics for researchers and engineers Presents the subject of computational fluid dynamics (CFD) and finite element methods (FEM) along with the high fidelity numerical analysis of recent applications in offshore mechanics Offers insight into the philosophy and power of numerical simulations and an understanding of the mathematical nature of the fluid and structural dynamics with focus on offshore mechanic applications Offshore Mechanics: Structural and Fluid Dynamics for Recent Applications is an important book for graduate and senior undergraduate students in offshore engineering and for offshore engineers and researchers in the offshore industry.

Offshore Energy Structures

Download Offshore Energy Structures PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319121758
Total Pages : 307 pages
Book Rating : 4.3/5 (191 download)

DOWNLOAD NOW!


Book Synopsis Offshore Energy Structures by : Madjid Karimirad

Download or read book Offshore Energy Structures written by Madjid Karimirad and published by Springer. This book was released on 2014-12-05 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides all the key information needed to design offshore structures for renewable energy applications successfully. Suitable for practicing engineers and students, the author conveys design principles and best practices in a clear, concise manner, focusing on underlying physics while eschewing complicated mathematical detail. The text connects underlying scientific theory with industry standards and practical implementation issues for offshore wind turbines, wave energy converters and current turbines. Combined concepts such as wave-wind energy platforms are discussed, as well. Coverage of design codes and numerical tools ensures the usefulness of this resource for all those studying and working in the rapidly expanding field of offshore renewable energy.

Coupled Dynamic Modeling of Floating Wind Turbine Systems

Download Coupled Dynamic Modeling of Floating Wind Turbine Systems PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 22 pages
Book Rating : 4.:/5 (79 download)

DOWNLOAD NOW!


Book Synopsis Coupled Dynamic Modeling of Floating Wind Turbine Systems by :

Download or read book Coupled Dynamic Modeling of Floating Wind Turbine Systems written by and published by . This book was released on 2006 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Reliability-Based Optimization of Floating Wind Turbine Support Structures

Download Reliability-Based Optimization of Floating Wind Turbine Support Structures PDF Online Free

Author :
Publisher : Springer Nature
ISBN 13 : 3030968898
Total Pages : 336 pages
Book Rating : 4.0/5 (39 download)

DOWNLOAD NOW!


Book Synopsis Reliability-Based Optimization of Floating Wind Turbine Support Structures by : Mareike Leimeister

Download or read book Reliability-Based Optimization of Floating Wind Turbine Support Structures written by Mareike Leimeister and published by Springer Nature. This book was released on 2023-01-01 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book pursues the ambitious goal of combining floating wind turbine design optimization and reliability assessment, which has in fact not been done before. The topic is organized into a series of very ambitious objectives, which start with an initial state-of-the-art review, followed by the development of high-fidelity frameworks for a disruptive way to design next generation floating offshore wind turbine (FOWT) support structures. The development of a verified aero-hydro-servo-elastic coupled numerical model of dynamics for FOWTs and a holistic framework for automated simulation and optimization of FOWT systems, which is later used for the coupling of design optimization with reliability assessment of FOWT systems in a computationally and time-efficient manner, has been an aim of many groups internationally towards implementing a performance-based/goal-setting approach in the design of complex engineering systems. The outcomes of this work quantify the benefits of an optimal design with a lower mass while fulfilling design constraints. Illustrating that comprehensive design methods can be combined with reliability analysis and optimization algorithms towards an integrated reliability-based design optimization (RBDO) can benefit not only the offshore wind energy industry but also other applications such as, among others, civil infrastructure, aerospace, and automotive engineering.

Coupled Dynamics and Economic Analysis of Floating Wind Turbine Systems

Download Coupled Dynamics and Economic Analysis of Floating Wind Turbine Systems PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 146 pages
Book Rating : 4.:/5 (767 download)

DOWNLOAD NOW!


Book Synopsis Coupled Dynamics and Economic Analysis of Floating Wind Turbine Systems by : Elizabeth N. Wayman

Download or read book Coupled Dynamics and Economic Analysis of Floating Wind Turbine Systems written by Elizabeth N. Wayman and published by . This book was released on 2006 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) This analysis tool was applied to several structures representing excerpts of the design space of structures capable of supporting large wind turbines. The structures were evaluated on their dynamic performance in several environmental conditions and on their installed cost. An economic analysis was also carried out to determine the cost of the floating platform for the wind turbine per kWh of electricity generated.

Sea Loads on Ships and Offshore Structures

Download Sea Loads on Ships and Offshore Structures PDF Online Free

Author :
Publisher : Cambridge University Press
ISBN 13 : 9780521458702
Total Pages : 344 pages
Book Rating : 4.4/5 (587 download)

DOWNLOAD NOW!


Book Synopsis Sea Loads on Ships and Offshore Structures by : O. Faltinsen

Download or read book Sea Loads on Ships and Offshore Structures written by O. Faltinsen and published by Cambridge University Press. This book was released on 1993-09-23 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: After introducing the theory of the structural loading on ships and offshore structures based on the motions of wind, waves and currents, this text demonstrates its applications to conventional and non-conventional sea vessels, including extensive exercises and examples.

Coupled Dynamic Analysis of Large-scale Mono-column Offshore Wind Turbine with a Single Tether Hinged in Seabed

Download Coupled Dynamic Analysis of Large-scale Mono-column Offshore Wind Turbine with a Single Tether Hinged in Seabed PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (817 download)

DOWNLOAD NOW!


Book Synopsis Coupled Dynamic Analysis of Large-scale Mono-column Offshore Wind Turbine with a Single Tether Hinged in Seabed by : Jieyan Chen

Download or read book Coupled Dynamic Analysis of Large-scale Mono-column Offshore Wind Turbine with a Single Tether Hinged in Seabed written by Jieyan Chen and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The increased interest in the offshore wind resource in both industry and academic and the extension of the wind field where offshore wind turbine can be deployed has stimulated quite a number of offshore wind turbines concepts. This thesis presents a design of mono-column platform supported for 5 MW baseline wind turbine developed by the National Renewable Energy Laboratory (NREL), with a single tether anchored to the seabed. The design, based on the pioneer concept SWAY®, results from parametric optimized design processes which account for important design considerations in the static and dynamic view, such as the stability, natural frequency, performance requirements as well as the economic feasibility. Fully coupled aero-hydro-servo-elastic model is established in the time-domain simulation tool FAST (Fatigue, Aerodynamics, Structures, and Turbulence) with the hydrodynamic coefficients from HydroGen, an indoor program providing same outputs as the commercial software WAMIT. The optimized model is verified by imitating the frequency-domain approach in FAST and thus comparing the results with the frequency-domain calculations. A number of simulations with various wind and wave conditions are run to explore the effect of wind speed and wave significant height in various water depths. By modifying the optimized model to a downwind turbine with the nacelle rigidly mounted on the tower and the single tether connected to the platform by a subsea swivel, the modified models are more closed to the original SWAY®-concept wind turbine. These models are compared based on the platform motion, tether tension, displacement, nacelle velocity and acceleration, resonant behavior as well as the damping of the coupled systems. The results of these comparisons prove the advantage of the modified model in performance. The modified model has also clarified itself a good candidate for deep water deployment.

Offshore Wind Energy Technology

Download Offshore Wind Energy Technology PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119097789
Total Pages : 459 pages
Book Rating : 4.1/5 (19 download)

DOWNLOAD NOW!


Book Synopsis Offshore Wind Energy Technology by : Olimpo Anaya-Lara

Download or read book Offshore Wind Energy Technology written by Olimpo Anaya-Lara and published by John Wiley & Sons. This book was released on 2018-05-11 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: A COMPREHENSIVE REFERENCE TO THE MOST RECENT ADVANCEMENTS IN OFFSHORE WIND TECHNOLOGY Offshore Wind Energy Technology offers a reference based on the research material developed by the acclaimed Norwegian Research Centre for Offshore Wind Technology (NOWITECH) and material developed by the expert authors over the last 20 years. This comprehensive text covers critical topics such as wind energy conversion systems technology, control systems, grid connection and system integration, and novel structures including bottom-fixed and floating. The text also reviews the most current operation and maintenance strategies as well as technologies and design tools for novel offshore wind energy concepts. The text contains a wealth of mathematical derivations, tables, graphs, worked examples, and illustrative case studies. Authoritative and accessible, Offshore Wind Energy Technology: Contains coverage of electricity markets for offshore wind energy and then discusses the challenges posed by the cost and limited opportunities Discusses novel offshore wind turbine structures and floaters Features an analysis of the stochastic dynamics of offshore/marine structures Describes the logistics of planning, designing, building, and connecting an offshore wind farm Written for students and professionals in the field, Offshore Wind Energy Technology is a definitive resource that reviews all facets of offshore wind energy technology and grid connection.

Airborne Wind Energy

Download Airborne Wind Energy PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 9811019479
Total Pages : 752 pages
Book Rating : 4.8/5 (11 download)

DOWNLOAD NOW!


Book Synopsis Airborne Wind Energy by : Roland Schmehl

Download or read book Airborne Wind Energy written by Roland Schmehl and published by Springer. This book was released on 2018-03-31 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides in-depth coverage of the latest research and development activities concerning innovative wind energy technologies intended to replace fossil fuels on an economical basis. A characteristic feature of the various conversion concepts discussed is the use of tethered flying devices to substantially reduce the material consumption per installed unit and to access wind energy at higher altitudes, where the wind is more consistent. The introductory chapter describes the emergence and economic dimension of airborne wind energy. Focusing on “Fundamentals, Modeling & Simulation”, Part I includes six contributions that describe quasi-steady as well as dynamic models and simulations of airborne wind energy systems or individual components. Shifting the spotlight to “Control, Optimization & Flight State Measurement”, Part II combines one chapter on measurement techniques with five chapters on control of kite and ground stations, and two chapters on optimization. Part III on “Concept Design & Analysis” includes three chapters that present and analyze novel harvesting concepts as well as two chapters on system component design. Part IV, which centers on “Implemented Concepts”, presents five chapters on established system concepts and one chapter about a subsystem for automatic launching and landing of kites. In closing, Part V focuses with four chapters on “Technology Deployment” related to market and financing strategies, as well as on regulation and the environment. The book builds on the success of the first volume “Airborne Wind Energy” (Springer, 2013), and offers a self-contained reference guide for researchers, scientists, professionals and students. The respective chapters were contributed by a broad variety of authors: academics, practicing engineers and inventors, all of whom are experts in their respective fields.

Dynamics Modeling, Simulation and Analysis of a Floating Offshore Wind Turbine

Download Dynamics Modeling, Simulation and Analysis of a Floating Offshore Wind Turbine PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (14 download)

DOWNLOAD NOW!


Book Synopsis Dynamics Modeling, Simulation and Analysis of a Floating Offshore Wind Turbine by : Mohammed Khair Al-Solihat

Download or read book Dynamics Modeling, Simulation and Analysis of a Floating Offshore Wind Turbine written by Mohammed Khair Al-Solihat and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: " Floating Offshore Wind Turbines (FOWTs) are a promising technology to harness the abundant offshore wind energy resources in open ocean areas. A FOWT consists of a floating platform, the moorings, and the wind turbine structure (tower + Rotor-Nacelle Assembly (RNA)). The main focus of this thesis is to develop multibody dynamic models that integrate the structural dynamics, and hydrostatic, hydrodynamic, aerodynamic and mooring system loads. Special efforts are also devoted to characterize the mooring and hydrostatic loads as main sources of systems stiffness that shapes the dynamic behavior of the system. Two approaches for modeling the platform/tower dynamics are developed, a rigid multibody model and a coupled rigid-flexible multibody model. Both models treat the platform, nacelle and rotor as six-degrees-of-freedom (6-DOF) rigid bodies. However, modeling the wind turbine tower dynamics differs between these approaches. The rigid model considers the tower as a 6-DOF rigid body while the flexible model represents the tower as a three-dimensional (3D) tapered damped Euler-Bernoulli beam undergoing coupled general rigid body and elastic motions. In both approaches, the wind turbine drivetrain dynamics is also considered to capture the rotor spin response. The equations of motions of both models are derived symbolically using Lagrange's equations. The hydrostatic restoring loads are evaluated through development of a novel nonlinear hydrostatic approach. This approach allows evaluating the exact hydrostatic force and moment and position of the center of buoyancy as function of the platform displacement and finite rotation. New exact expressions for the water plane area restoring moments are developed. The hydrostatic stiffness matrix at an arbitrary position and orientation of the platform is subsequently derived. A quasi-static approach is then developed to determine the cable tensions of the single-segment and multi-segment mooring system configurations proposed to moor the platform to the seabed. The approach uses different governing equations, depending on whether the mooring lines partially rest on the seabed; are suspended; or fully taut. The exact mooring stiffness is subsequently derived and the influence of several mooring system parameters on the mooring system stiffness is investigated. As an alternative to the quasi-static cable model, a lumped mass cable model incorporating the cable-seabed contact effect is developed to integrate the cable dynamics into the FOWT system dynamics. The equations of motion of the mooring line nodes are assembled for the two mooring system configurations under consideration. A new methodology is also presented to calculate the equilibrium profile of the mooring line lying on a seabed as desirable initial conditions for solving the discretized cable equations of motion. Finally, the theoretical models are implemented through a large simulation tool to analyze the dynamic behavior of the spar FOWT system under study. A series of simulations under defined external loads (load cases) are performed to validate the dynamic models. The simulation results are compared with similar results obtained from well-known offshore wind design codes. The simulation results are found to be in very good agreement with the reported results. Numerical experiments are also performed to investigate the influence of the tower flexibility, mooring system configuration, tower twist and cable dynamics on the system dynamic behavior. The results show that the system responses obtained from the rigid body model under-predict the platform yaw response and exhibit less damping than those obtained from the flexible model. It is also found that the mooring system configuration choice does not influence the platform roll and pitch responses or tower elastic deflections." --

MARE-WINT

Download MARE-WINT PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 3319390953
Total Pages : 432 pages
Book Rating : 4.3/5 (193 download)

DOWNLOAD NOW!


Book Synopsis MARE-WINT by : Wiesław Ostachowicz

Download or read book MARE-WINT written by Wiesław Ostachowicz and published by Springer. This book was released on 2016-08-30 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a holistic, interdisciplinary overview of offshore wind energy, and is a must-read for advanced researchers. Topics, from the design and analysis of future turbines, to the decommissioning of wind farms, are covered. The scope of the work ranges from analytical, numerical and experimental advancements in structural and fluid mechanics, to novel developments in risk, safety & reliability engineering for offshore wind.The core objective of the current work is to make offshore wind energy more competitive, by improving the reliability, and operations and maintenance (O&M) strategies of wind turbines. The research was carried out under the auspices of the EU-funded project, MARE-WINT. The project provided a unique opportunity for a group of researchers to work closely together, undergo multidisciplinary doctoral training, and conduct research in the area of offshore wind energy generation. Contributions from expert, external authors are also included, and the complete work seeks to bridge the gap between research and a rapidly-evolving industry.