Computation of Wave Loads under Multidirectional Sea States for Floating Offshore Wind Turbines: Preprint

Computation of Wave Loads under Multidirectional Sea States for Floating Offshore Wind Turbines: Preprint

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Publisher:

Published: 2014

Total Pages: 0

ISBN-13:

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This paper focuses on the analysis of a floating wind turbine under multidirectional wave loading. Special attention is given to the different methods used to synthesize the multidirectional sea state. This analysis includes the double-sum and single-sum methods, as well as an equal-energy discretization of the directional spectrum. These three methods are compared in detail, including theergodicity of the solution obtained. From the analysis, the equal-energy method proved to be the most computationally efficient while still retaining the ergodicity of the solution. This method was chosen to be implemented in the numerical code FAST. Preliminary results on the influence of these wave loads on a floating wind turbine showed significant additional roll and sway motion of theplatform.


9th Australasian Conference on Coastal and Ocean Engineering, Adelaide, 4-8 December 1989

9th Australasian Conference on Coastal and Ocean Engineering, Adelaide, 4-8 December 1989

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Publisher:

Published: 1989

Total Pages: 528

ISBN-13:

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Preprints of papers read at the Dec. 1989 meeting in Adelaide. It is Institute of Engineers, Australia National Conference Publication no. 89/20. They deal with: results of theoretical and experimental research; data collection analysis and interpretation; estuary and lagoon hydrodynamics; coastal erosion and protection; environmental aspects of beaches and estuaries; strategies for long-term coastal management; and offshore engineering. No index. Acidic paper. Annotation copyrighted by Book News, Inc., Portland, OR


A comparison of methods for computation of wave forcing

A comparison of methods for computation of wave forcing

Author: Olga Glöckner

Publisher: GRIN Verlag

Published: 2018-05-17

Total Pages: 137

ISBN-13: 3668705224

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Diploma Thesis from the year 2014 in the subject Engineering - Civil Engineering, grade: 1,0, University of Hannover (A&M University Texas, Ludwig-Franzius-Institut für Wasserbau, Ästuar- und Küsteningenieurwesen), language: English, abstract: Unlike fossil fuels (for example oil, coal and natural gas), wind energy is a renewable energy resource. Since winds at sea are stronger and more consistent than onshore winds, the demand for offshore wind turbines has increased over the last years. As energy can be produced more efficient in deeper water, several floating offshore wind turbine constructions, such as the OC3 Hywind spar-buoy, have been proposed. The design of floating wind turbines depends on the simulation of the system behavior caused by exciting forces. This thesis deals with the comparison between different methods for calculating wave forces and resulting platform motions of a floating offshore wind turbine. On the one hand, wave exciting loads computed with Morison’s equation are compared to the hydrodynamic forces simulated by the open source code FAST on the basis of the diffraction theory. On the other hand, response motions of the floating structure are simulated by the commercial offshore software SESAM in the frequency domain and compared with the motions calculated by FAST in the time domain.


Ocean Wave Energy Conversion

Ocean Wave Energy Conversion

Author: Aurelien Babarit

Publisher: Elsevier

Published: 2017-11-17

Total Pages: 264

ISBN-13: 0081023901

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The waves that animate the surface of the oceans represent a deposit of renewable energy that for the most part is still unexploited today. This is not for lack of effort, as for more than two hundred years inventors, researchers and engineers have struggled to develop processes and systems to recover the energy of the waves. While all of these efforts have failed to converge towards a satisfactory technological solution, the result is a rich scientific and technical literature as well as extensive and varied feedback from experience. For the uninitiated, this abundance is an obstacle. In order to facilitate familiarization with the subject, we propose in this work a summary of the state of knowledge on the potential of wave energy as well as on the processes and technologies of its recovery (wave energy converters). In particular, we focus on the problem of positioning wave energy in the electricity market, the development of wave energy conversion technologies from a historical perspective, and finally the energy performance of the devices. This work is aimed at students, researchers, developers, industry professionals and decision makers who wish to acquire a global perspective and the necessary tools to understand the field. - Reviews the state of knowledge and developments on wave energy recovery - Presents the history of wave energy recovery - Classifies the various systems for recovering this type of energy


Floating Offshore Wind Energy

Floating Offshore Wind Energy

Author: Joao Cruz

Publisher: Springer

Published: 2016-08-20

Total Pages: 345

ISBN-13: 3319293982

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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.


Comparison of methods for the computation of wave forcing

Comparison of methods for the computation of wave forcing

Author: Olga Glöckner

Publisher: GRIN Verlag

Published: 2018-05-18

Total Pages: 20

ISBN-13: 366870614X

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Presentation slides from the year 2014 in the subject Engineering - Civil Engineering, grade: 1,0, University of Hannover, language: English, abstract: Unlike fossil fuels (e.g. oil, coal and natural gas), wind energy is a renewable energy resource. Since winds at sea are stronger and more consistent than onshore winds, the demand for offshore wind turbines has increased over the last years. As energy can be produced more efficient in deeper water, several floating offshore wind turbine constructions, such as the OC3 Hywind spar-buoy, have been proposed. The design of floating wind turbines depends on the simulation of the system behavior caused by exciting forces. This thesis deals with the comparison between different methods for calculating wave forces and resulting platform motions of a floating offshore wind turbine. On the one hand, wave exciting loads computed with Morison’s equation are compared to the hydrodynamic forces simulated by the open source code FAST on the basis of the diffraction theory. On the other hand, response motions of the floating structure are simulated by the commercial offshore software SESAM in the frequency domain and compared with the motions calculated by FAST in the time domain.


Wind energy. Methods for computation of wave forcing and the resulting motion of a slender offshore floating structure

Wind energy. Methods for computation of wave forcing and the resulting motion of a slender offshore floating structure

Author: Olga Glöckner

Publisher: GRIN Verlag

Published: 2018-07-19

Total Pages: 151

ISBN-13: 3668754780

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Academic Paper from the year 2014 in the subject Engineering - Civil Engineering, grade: 1,0, University of Hannover (A&M University Texas, Ludwig-Franzius-Institut für Wasserbau, Ästuar- und Küsteningenieurwesen), language: English, abstract: This thesis investigates how wave loads act on an OC3 Hywind spar-buoy. The author analyzes the resulting motions of the support platform. This work also contains a detailed presentation of the topic with useful additional information and graphics. Unlike fossil fuels (like oil, coal and natural gas), wind energy is a renewable energy resource. Since winds at sea are stronger and more consistent than onshore winds, the demand for offshore wind turbines has increased over the last years. As energy can be produced more efficient in deeper water, several floating offshore wind turbine constructions, such as the OC3 Hywind spar-buoy, have been proposed. The design of floating wind turbines depends on the simulation of the system behavior caused by exciting forces. A general overview of regular and irregular waves as well as hydrostatic and hydrodynamic loads acting on floating structures is given in chapter 2. Furthermore, essential formulations for calculating motions of FOWTs are given at the end of this chapter. Since all simulations carried out in this thesis are based on the OC3 Hywind concept, detailed information about this floating wind turbine model are given in chapter 3. Three different methods are used for the estimation of wave induced loads and motions. Section 4 describes a modified Morison formulation in the time domain which is applied by the commercially available software MATLAB. On the basis of the diffraction theory the commercial offshore software package SESAM simulates wave excitation forces and responding motions which are presented and discussed in chapter 5. The third method is the open source code FAST that computes wave induced loads and motions based on the first-order potential theory and Kane’s equation of motion. Basic formulations used in FAST and essential hydrodynamic results are shown in chapter 6. The comparisons between the simulations of the three programs are represented and the individual results are analyzed in chapter 7.


Fundamentals of Ship Hydrodynamics

Fundamentals of Ship Hydrodynamics

Author: Lothar Birk

Publisher: John Wiley & Sons

Published: 2019-04-25

Total Pages: 876

ISBN-13: 1118855515

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Fundamentals of Ship Hydrodynamics: Fluid Mechanics, Ship Resistance and Propulsion Lothar Birk, University of New Orleans, USA Bridging the information gap between fluid mechanics and ship hydrodynamics Fundamentals of Ship Hydrodynamics is designed as a textbook for undergraduate education in ship resistance and propulsion. The book provides connections between basic training in calculus and fluid mechanics and the application of hydrodynamics in daily ship design practice. Based on a foundation in fluid mechanics, the origin, use, and limitations of experimental and computational procedures for resistance and propulsion estimates are explained. The book is subdivided into sixty chapters, providing background material for individual lectures. The unabridged treatment of equations and the extensive use of figures and examples enable students to study details at their own pace. Key features: • Covers the range from basic fluid mechanics to applied ship hydrodynamics. • Subdivided into 60 succinct chapters. • In-depth coverage of material enables self-study. • Around 250 figures and tables. Fundamentals of Ship Hydrodynamics is essential reading for students and staff of naval architecture, ocean engineering, and applied physics. The book is also useful for practicing naval architects and engineers who wish to brush up on the basics, prepare for a licensing exam, or expand their knowledge.