Download or read book Development and Verification of a CFD Based Simulation Software for Floating Offshore Wind Turbines written by Sean M. Quallen and published by . This book was released on 2015 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: A coupled aerodynamic-hydrodynamic-servo simulation software capable of motion and performance predictions for floating offshore wind turbines (FOWT) is developed. The computational fluid dynamics (CFD) solver CFDShip-Iowa is used for pressure, velocity, and motion predictions. A multi-segmented mooring line model (crowfoot) is designed for securing the turbine and limiting motions. Variable-speed (VS) and blade-pitch (BP) controllers designed by the National Renewable Energy Laboratory (NREL) are also utilized to help maximize power and to prevent generator overload. The developed software is demonstrated with multiple simulation load cases (LC) from the Offshore Code Comparison Collaboration (OC3), increasing complexity with each simulation. Free-decay tests are first performed for hydrodynamic validation against experimental data provided by the OC3 using a coarse grid set. A URANS simulation featuring steady wind and regular wave patterns, modeled after the OC3's LC 5.1, is performed with a fixed rotor rotational velocity. The motion and aerodynamic power predictions are compared to those of NREL's OC3 results. A finer gridset is constructed and utilized in a study of offshore blade-tower interaction (BTI) to determine the effect of unsteady platform motions on the aerodynamic disruption caused by the blade passing directly upwind of the tower. The results show that BTI effects are strongly affected by platform motions, notably in pitch, and that BTI is more significantly affected by platform velocities than by overall displacements. This finer gridset is again utilized, but combined with a VS controller in a duplicate LC 5.1 simulation using DDES. The drivetrain is modeled with rotational inertia allowing for prediction of the rotor velocity based on developed generator torque. Generator torque and power predictions are compared to NREL's results. The present results agree in frequency trends but predict separation on blades during platform upstream pitching and surging. The BP controller is employed in a simulation modeled after the OC3's LC 5.2, which uses irregular waves and the Mann wind turbulence model. Results are transformed to the frequency domain for comparison with NREL. The present results agree with NREL generated torque and power. Grid dissipation and modeling error in the present study produce less overall wind and wave fluctuations.

Download or read book Simulating The Hydrodynamics Of Offshore Floating Wind Turbine Platforms In A Finite Volume Framework written by Maija Benitz and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There is great potential for the growth of wind energy in offshore locations where the structures are exposed to a variety of loading from waves, current and wind. A variety of computer-aided engineering (CAE) tools, based largely on engineering models employing potential-flow theory and/or Morison's equation, are currently being used to evaluate hydrodynamic loading on floating offshore wind turbine platforms. While these models are computationally inexpensive, they include many assumptions and approximations. Alternatively, high-fidelity computational fluid dynamics models contain almost no assumptions, but at the cost of high computational expense. In this work, CFD simulations provide detailed insight into the complex fluid flow that has not been captured experimentally, nor can be attained with reduced-order models. This work includes a thorough validation of the various CFD toolboxes necessary for simulating offshore floating wind turbine platforms in the ocean environment, from numerical wave propagation to fluid-structure interactions. The fundamental physics of flow around complex structures is examined through various studies to better understand the effects of a fluid interface, truncated ends, structure size, multi-member arrangements and environmental conditions. These factors are explored in terms of drag, lift and frequency of the loads. Additionally, motion of structures in free decay tests and waves are investigated. The work provides insight into the complex fluid flow around floating offshore structures of small draft in a variety of environmental conditions. CFD simulations are used to assess assumptions and approximations of reduced-order engineering models, and explain why, and in which conditions, these models perform inaccurately. Finally, the work provides suggestions for improvements to engineering tools often used for hydrodynamics modeling of floating offshore wind turbines.

Download or read book Recent Advances in CFD for Wind and Tidal Offshore Turbines written by Esteban Ferrer and published by Springer. This book was released on 2019-02-06 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents novel Computational Fluid Dynamics (CFD) techniques to compute offshore wind and tidal applications. The papers in this volume are based on a mini-symposium held at ECCOMAS 2018. Computational fluid dynamics (CFD) techniques are regarded as the main design tool to explore the new engineering challenges presented by offshore wind and tidal turbines for energy generation. The difficulty and costs of undertaking experimental tests in offshore environments have increased the interest in CFD which is used to design appropriate turbines and blades, understand fluid flow physical phenomena associated with offshore environments, predict power production or characterise offshore environments amongst other topics.

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.

Download or read book CFD for Wind and Tidal Offshore Turbines written by Esteban Ferrer and published by Springer. This book was released on 2015-06-09 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book encompasses novel CFD techniques to compute offshore wind and tidal applications. Computational fluid dynamics (CFD) techniques are regarded as the main design tool to explore the new engineering challenges presented by offshore wind and tidal turbines for energy generation. The difficulty and costs of undertaking experimental tests in offshore environments have increased the interest in the field of CFD which is used to design appropriate turbines and blades, understand fluid flow physical phenomena associated with offshore environments, predict power production or characterise offshore environments, amongst other topics.

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." --

Download or read book Development and Verification of a Fully Coupled Simulator for Offshore Wind Turbines written by and published by . This book was released on 2007 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report outlines the development of an analysis tool capable of analyzing a variety of wind turbine, support platform, and mooring system configurations. The simulation capability was tested by model-to-model comparisons to ensure its correctness.

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.

Download or read book Openfoam for Wind Energy Engineering How to Use the Open Source Toolbox for Wind Energy Related CFD Simulations written by Bernhard Stoevesandt and published by Academic Press. This book was released on 2018-09 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: OpenFOAM for Wind Energy Engineering: How to use the Open-Source Toolbox for Wind Energy-Related CFD Simulations is a concise, approachable and clear guide for wind engineers and students facing the steep learning curve associated with using this powerful, yet complex, software. The book addresses the specific problems and challenges users encounter when using OpenFOAM for wind energy applications and provides solutions and/or approaches to solutions that are dependent on the problem. The book is an essential introduction to an important open-source tool that was written specifically to meet the information needs of wind industry professionals, researchers and graduate students studying wind energy. Addresses the specific challenges users encounter when using OpenFOAM for wind energy applications Goes into detail on topics crucial for wind engineers that aren't covered in general OpenFOAM manuals, such as turbulence models in thick airfoil simulations and the simulation of rotating turbines Includes downloadable code that users can use to quickly get started when using OpenFOAM for wind energy applications for the first time

Download or read book A Comparison Between CFD based Aerodynamic Models and BEM Theory based Models Applied in Coupled Simulations of Floating Offshore Wind Turbines written by Rachael Smith and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Coupled MBS CFD Simulation of the IDEOL Floating Offshore Wind Turbine Foundation Compared to Wave Tank Model Test Data written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book The Elements of Aerofoil and Airscrew Theory written by Hermann Glauert and published by . This book was released on 1926 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Wind Resource Assessment written by Michael Brower and published by John Wiley & Sons. This book was released on 2012-06-19 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical, authoritative guide to the assessment of wind resources for utility-scale wind projects authored by a team of experts from a leading renewable energy consultancy The successful development of wind energy projects depends on an accurate assessment of where, how often, and how strongly the wind blows. A mistake in this stage of evaluation can cause severe financial losses and missed opportunities for developers, lenders, and investors. Wind Resource Assessment: A Practical Guide to Developing a Wind Project shows readers how to achieve a high standard of resource assessment, reduce the uncertainty associated with long-term energy performance, and maximize the value of their project assets. Beginning with the siting, installation, and operation of a high-quality wind monitoring program, this book continues with methods of data quality control and validation, extrapolating measurements from anemometer height to turbine height, adjusting short-term observations for historical climate conditions, and wind flow modeling to account for terrain and surface conditions. In addition, Wind Resource Assessment addresses special topics such as: Worker safety Data security Remote sensing technology (sodar and lidar) Offshore resource assessment Impacts of climate change Uncertainty estimation Plant design and energy production estimatio Filled with important information ranging from basic fundamentals of wind to cutting-edge research topics, and accompanied by helpful references and discussion questions, this comprehensive text designed for an international audience is a vital reference that promotes consistent standards for wind assessment across the industry.

Download or read book New Modeling Tool Analyzes Floating Platform Concepts for Offshore Wind Turbines Fact Sheet written by and published by . This book was released on 2011 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers at the National Renewable Energy Laboratory (NREL) developed a new complex modeling and analysis tool capable of analyzing floating platform concepts for offshore wind turbines. The new modeling tool combines the computational methodologies used to analyze land-based wind turbines with the comprehensive hydrodynamic computer programs developed for offshore oil and gas industries. This new coupled dynamic simulation tool will enable the development of cost-effective offshore technologies capable of harvesting the rich offshore wind resources at water depths that cannot be reached using the current technology.