Download or read book Analysis of a Rotatable Wind Turbine Tower by means of Aero Servo Elastic Load Simulations written by Struve, Achim and published by KIT Scientific Publishing. This book was released on 2021-04-12 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work highlights how the costs and CO2-emissions of land-based wind turbines can be reduced by means of an innovative and material efficient support structure concept. Thereby the yaw system is placed at the tower base, allowing the whole wind turbine tower to be rotated. The potential of a rotatable inclined lattice tower concept was analysed by means of aero-servo-elastic load simulations in the FAST environment. A balance between different cost aspects revealed significant savings.
Download or read book Analysis of a Rotatable Wind Turbine Tower by Means of Aero servo elastic Load Aimulations written by Achim Struve and published by . This book was released on 2020* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Cast Steel Components under Cyclic Loading written by Nagel, Sven and published by KIT Scientific Publishing. This book was released on 2022-05-27 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a design approach that links fatigue resistance of cast steel component to permissible defect sizes. It is based on fractures mechanics, is in line with experiences of the last 60 years and validated by extensive experimental as well as numerical investigations on different scales and under consideration of real casting defects. By following established assessment methods, the design concept is adapted to practical building applications.
Download or read book Finite Element Simulation of Residual Stresses from Welding and High Frequency Hammer Peening written by Gkatzogiannis, Stefanos and published by KIT Scientific Publishing. This book was released on 2022-06-30 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research goal of the present monograph is the establishment of an efficient engineering approach, which will include straightforward but accurate simulation models, in order to estimate the residual stress fields of welded joints introduced during welding and their post-weld treatment with High Frequency Hammer Peening. The present subject lies on the intersection of structural engineering, material science and computational mechanics.
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.
Download or read book Maritime Engineering and Technology written by Carlos Guedes Soares and published by CRC Press. This book was released on 2012-11-26 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: Maritime Engineering and Technology includes the papers from the 1st International Conference on Maritime Technology and Engineering (MARTECH 2011, Lisbon, Portugal, 10-12 May 2011). MARTECH 2011 was held to commemorate 100 years of the Instituto Superior Tico (IST) in Lisbon, and the contributions in the present volume reflect the
Download or read book Fully vs Sequentially Coupled Loads Analysis of Offshore Wind Turbines written by and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and analysis methods for offshore wind turbines must consider the aerodynamic and hydrodynamic loads and response of the entire system (turbine, tower, substructure, and foundation) coupled to the turbine control system dynamics. Whereas a fully coupled (turbine and support structure) modeling approach is more rigorous, intellectual property concerns can preclude this approach. In fact, turbine control system algorithms and turbine properties are strictly guarded and often not shared. In many cases, a partially coupled analysis using separate tools and an exchange of reduced sets of data via sequential coupling may be necessary. In the sequentially coupled approach, the turbine and substructure designers will independently determine and exchange an abridged model of their respective subsystems to be used in their partners' dynamic simulations. Although the ability to achieve design optimization is sacrificed to some degree with a sequentially coupled analysis method, the central question here is whether this approach can deliver the required safety and how the differences in the results from the fully coupled method could affect the design. This work summarizes the scope and preliminary results of a study conducted for the Bureau of Safety and Environmental Enforcement aimed at quantifying differences between these approaches through aero-hydro-servo-elastic simulations of two offshore wind turbines on a monopile and jacket substructure.
Download or read book Handbook of Wind Energy Aerodynamics written by Bernhard Stoevesandt and published by Springer Nature. This book was released on 2022-08-04 with total page 1495 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook provides both a comprehensive overview and deep insights on the state-of-the-art methods used in wind turbine aerodynamics, as well as their advantages and limits. The focus of this work is specifically on wind turbines, where the aerodynamics are different from that of other fields due to the turbulent wind fields they face and the resultant differences in structural requirements. It gives a complete picture of research in the field, taking into account the different approaches which are applied. This book would be useful to professionals, academics, researchers and students working in the field.
Download or read book Wind Turbine Aerodynamics and Vorticity Based Methods written by Emmanuel Branlard and published by Springer. This book was released on 2017-04-05 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces the fundamentals of fluid-mechanics, momentum theories, vortex theories and vortex methods necessary for the study of rotors aerodynamics and wind-turbines aerodynamics in particular. Rotor theories are presented in a great level of details at the beginning of the book. These theories include: the blade element theory, the Kutta-Joukowski theory, the momentum theory and the blade element momentum method. A part of the book is dedicated to the description and implementation of vortex methods. The remaining of the book focuses on the study of wind turbine aerodynamics using vortex-theory analyses or vortex-methods. Examples of vortex-theory applications are: optimal rotor design, tip-loss corrections, yaw-models and dynamic inflow models. Historical derivations and recent extensions of the models are presented. The cylindrical vortex model is another example of a simple analytical vortex model presented in this book. This model leads to the development of different BEM models and it is also used to provide the analytical velocity field upstream of a turbine or a wind farm under aligned or yawed conditions. Different applications of numerical vortex methods are presented. Numerical methods are used for instance to investigate the influence of a wind turbine on the incoming turbulence. Sheared inflows and aero-elastic simulations are investigated using vortex methods for the first time. Many analytical flows are derived in details: vortex rings, vortex cylinders, Hill's vortex, vortex blobs etc. They are used throughout the book to devise simple rotor models or to validate the implementation of numerical methods. Several Matlab programs are provided to ease some of the most complex implementations.
Download or read book Elastic Actuator Line Modelling for the Wake induced Fatigue Analysis of Horizontal Wind Turbine written by Hang Meng and published by . This book was released on 2018 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue damage on wind turbine blades will threaten the safety and stability of the wind turbine and thus lower the efficiency and economy of the power generation system. The wake-induced fatigue plays an important role in this fatigue damage, which has not been deeply studied in the previous research of this domain. This is because the calculation of fatigue damage on a wind turbine blade under wake conditions will include the knowledge of wind turbine wake (fluid mechanics), composite structure modelling (solid structure modelling), aero-elastic modelling (coupling between fluid and structures), and fatigue analysis. Moreover, the anisotropic composite wind turbine blade, e.g. bendtwist coupling blade, will also bring challenges for the structural modelling. To propose a model to solve the above problems holistically is the motivation of the thesis. In this thesis, to construct the aero-elastic model under wake conditions for fatigue analysis, the elastic actuator line model is proposed and verified. To consider the anisotropic properties of composite wind turbine blade, e.g. bend-twist coupling wind turbine blade, the anisotropic wind turbine blade structure model is constructed. Based on the structure model and cross sectional analysis method (BECAS), the fatigue analysis methodology is proposed. Due to the similarity between the anisotropic wind turbine blade structure model and Maxwell's equation (electromagnetic equations), the FDTD method, which is a FDM based method and long been used in electromagnetic simulation, is applied to construct a novel anisotropic wind turbine blade structure model. Specifically, firstly, the actuator line model is validated in terms of thrust coefficient and flow field prediction. It is found that the nacelle effect has impact on the velocity profile around wake center region. And the proposed single-point nacelle model, single momentum source point smeared by Gaussian function, can be used to correct the prediction not only for RANS turbulence model but also for LES turbulence model. Secondly, Based on NREL SOWFA, the elastic actuator line model is constructed as an aero-elastic model for wake conditions to simulate the dynamic loading of wind turbine blade. The stochastic and deterministic wake-induced fatigue loading are reproduced by the proposed elastic actuator line model. Compared with the explicit elastic actuator line model, the implicit elastic actuator line can run with larger time step. However, the accuracy of implicit method will decrease. Thirdly, the performance of normal and bend-twist coupling wind turbine blade with anisotropic composite materials in wake conditions are studied by using the fatigue analysis methodology based on anisotropic structure model, cross sectinal analysis, and fatigue analysis method. Based on this fatigue analysis methodology, the fatigue life of NREL 5MW wind turbine blade is analysed. The predicted fatigue life (26.0187 years) of the main structure (spar caps) is very close to the design life (20 years). From the fatigue analysis for wind turbines in wake conditions, it is found that the wake-induced fatigue has a significant impact on the fatigue life of wind turbine blades (fatigue life drops from 26.0187 years to 1.7388 years under compact layout). And wind farm layout can affect the wake-induced fatigue damage (increase from 1.7388 years (compact layout) to 6.9084 years (normal layout)). Furthermore, it is also found that the bend-twist coupling wind turbine blade can alleviate the fatigue load under wake condition. Lastly, the structure model based on FDTD method is constructed for anisotropic wind turbine blade and validated in terms of beams with deformation coupling, non-inertia coordinate system, and non-uniform sections (real wind turbine blade). The stability analysis for the proposed FDTD model is carried out, which shows that the root cause of the numerical instability for the proposed method is the highest-frequency mode in numerical model. Based on this analysis, the unconditionally stable explicit FDTD structure model is proposed and constructed, which strikes a balance between accuracy and efficiency. Compared with implicit method, the unconditionally stable explicit FDTD model overcomes its limitations on time step with little effect on its solution accuracy.
Download or read book Renewable Energies Offshore written by C. Guedes Soares and published by CRC Press. This book was released on 2015-09-07 with total page 1030 pages. Available in PDF, EPUB and Kindle. Book excerpt: Renewable Energies Offshore includes the papers presented in the 1st International Conference on Renewable Energies Offshore (RENEW2014), held in Lisbon, 24-26 November 2014. The conference is a consequence of the importance of the offshore renewable energies worldwide and an opportunity to contribute to the exchange of information on the dev
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.
Download or read book Proceedings of the 20th International Ship and Offshore Structures Congress ISSC 2018 Volume 3 written by M.L. Kaminski and published by IOS Press. This book was released on 2020-02-21 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Ship and Offshore Structures Congress (ISSC) is a forum for the exchange of information by experts undertaking and applying marine structural research. The aim of the ISSC is to facilitate the evaluation and dissemination of results from recent investigations, to make recommendations for standard design procedures and criteria, to discuss research in progress and planned, to identify areas requiring future research and to encourage international collaboration in furthering these aims. Ships and other marine structures used for transportation, exploration and exploitation of resources in and under the oceans are in the scope of the ISSC. The 20th International Ship and Offshore Structures Congress (ISSC 2018) was held in (Liège) Belgium and Amsterdam (The Netherlands), 9–14 September 2018. The first volume of the proceedings contains the eight Technical Committee reports presented and discussed at the conference and the second volume contains the reports of the eight Specialist Committees. This third volume contains the Official discusser's reports, written discussions and floor discussions, and the replies by the committees.
Download or read book Maritime Technology and Engineering 5 Volume 2 written by Carlos Guedes Soares and published by CRC Press. This book was released on 2021-07-08 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt: This set of two volumes comprises the collection of the papers presented at the 5th International Conference on Maritime Technology and Engineering (MARTECH 2020) that was held in Lisbon, Portugal, from 16 to 19 November 2020. The Conference has evolved from the series of biennial national conferences in Portugal, which have become an international event, and which reflect the internationalization of the maritime sector and its activities. MARTECH 2020 is the fifth of this new series of biennial conferences. The set comprises 180 contributions that were reviewed by an International Scientific Committee. Volume 2 is dedicated to ship performance and hydrodynamics, including CFD, maneuvering, seakeeping, moorings and resistance. In addition, it includes sections on ship machinery, renewable energy, fishing and aquaculture, coastal structures, and waves and currents.
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.
Download or read book Aerodynamics of Wind Turbines written by Sven Schmitz and published by John Wiley & Sons. This book was released on 2019-07-31 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the aerodynamics, design and analysis, and optimization of wind turbines, combined with the author’s unique software Aerodynamics of Wind Turbines is a comprehensive introduction to the aerodynamics, scaled design and analysis, and optimization of horizontal-axis wind turbines. The author –a noted expert on the topic – reviews the fundamentals and basic physics of wind turbines operating in the atmospheric boundary layer. He then explores more complex models that help in the aerodynamic analysis and design of turbine models. The text contains unique chapters on blade element momentum theory, airfoil aerodynamics, rotational augmentation, vortex-wake methods, actuator-line modeling, and designing aerodynamically scaled turbines for model-scale experiments. The author clearly demonstrates how effective analysis and design principles can be used in a wide variety of applications and operating conditions. The book integrates the easy-to-use, hands-on XTurb design and analysis software that is available on a companion website for facilitating individual analyses and future studies. This component enhances the learning experience and helps with a deeper and more complete understanding of the subject matter. This important book: Covers aerodynamics, design and analysis and optimization of wind turbines Offers the author’s XTurb design and analysis software that is available on a companion website for individual analyses and future studies Includes unique chapters on blade element momentum theory, airfoil aerodynamics, rotational augmentation, vortex-wake methods, actuator-line modeling, and designing aerodynamically scaled turbines for model-scale experiments Demonstrates how design principles can be applied to a variety of applications and operating conditions Written for senior undergraduate and graduate students in wind energy as well as practicing engineers and scientists, Aerodynamics of Wind Turbines is an authoritative text that offers a guide to the fundamental principles, design and analysis of wind turbines.
Download or read book Development of an Aeroelastic Simulation for the Analysis of Vertical axis Wind Turbines written by Gareth Marc Ferrari and published by . This book was released on 2012 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: Like their horizontal-axis counterparts, as the blades of vertical-axis wind turbines increase in size they typically become relatively more flexible so a better understanding of their aeroelastic behaviour is required. This research addresses the challenges of large, flexible, vertical-axis wind turbines using methods previously unavailable, or impractical due to limited computational resources. A weakly-coupled aeroelastic simulation was developed to investigate the dynamic behaviour of vertical-axis wind turbines. The aeroelastic simulation comprised a free vortex wake model to represent the aerodynamics, and a multibody systems model to represent the structural dynamics, with the models coupled together via an interface. A modified version of the Beddoes- Leishman dynamic stall model was used to account for unsteady aerodynamic effects on the blades. The modal characteristics of the structural model were extracted using the Eigensystem Realisation Algorithm. The aerodynamic aspects of the simulation were validated against a wide range of experimental data. The structural aspects of the simulation were verified against an industry-standard multi-body systems package, and validated against a combination of analytical, numerical and experimental data. An extensive set of tests were conducted on the aerodynamic and structural models demonstrating that quite computationally undemanding methods for the computational parameters, including the time-step sizes and levels of blade discretisation, were capable of producing results very similar to those predicted using much more computationally demanding values. The aeroelastic simulation was used to conduct a number of numerical experiments designed to aid an investigation into how the aeroelastic behaviour of a large-scale baseline turbine configuration changed in response to various parameters. It was shown that the asymmetric loading along the blades, caused by a combination of the gravitational loads and the vertical variation in height of the wind speed, results in a periodic vertical rocking motion of the blades. This rocking motion occurred at a frequency of twice per revolution. It enabled new insight into the dynamic motion of VAWT blades. It was also found that the periodic rocking motion could be reduced by increasing the stiffness of the blades and reducing the linear density of the blades.