Analysis of a Rotatable Wind Turbine Tower by means of Aero-Servo-Elastic Load Simulations


Book Description

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.




Design of Cast Steel Components under Cyclic Loading


Book Description

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.




Finite Element Simulation of Residual Stresses from Welding and High Frequency Hammer Peening


Book Description

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.




Maritime Engineering and Technology


Book Description

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




Handbook of Wind Energy Aerodynamics


Book Description

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.




Renewable Energies Offshore


Book Description

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




Proceedings of the 20th International Ship and Offshore Structures Congress (ISSC 2018) Volume 3


Book Description

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.




Maritime Technology and Engineering 5 Volume 2


Book Description

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.




Wind Turbine Aerodynamics and Vorticity-Based Methods


Book Description

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.




Aerodynamics of Wind Turbines, 2nd edition


Book Description

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.