Download or read book Preliminary Analysis of an Oscillating Surge Wave Energy Converter with Controlled Geometry Preprint written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this paper is to present a novel wave energy converter device concept that is being developed at the National Renewable Energy Laboratory. The proposed concept combines an oscillating surge wave energy converter with active control surfaces. These active control surfaces allow for the device geometry to be altered, which leads to changes in the hydrodynamic properties. The device geometry will be controlled on a sea state time scale and combined with wave-to-wave power-take-off control to maximize power capture, increase capacity factor, and reduce design loads. The paper begins with a traditional linear frequency domain analysis of the device performance. Performance sensitivity to foil pitch angle, the number of activated foils, and foil cross section geometry is presented to illustrate the current design decisions; however, it is understood from previous studies that modeling of current oscillating wave energy converter designs requires the consideration of nonlinear hydrodynamics and viscous drag forces. In response, a nonlinear model is presented that highlights the shortcomings of the linear frequency domain analysis and increases the precision in predicted performance.

Download or read book Development of the Second Generation Oscillating Surge Wave Energy Converter with Variable Geometry Preprint written by and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates the effect of design changes on the hydrodynamics of a novel oscillating surge wave energy converter being developed at the National Renewable Energy Laboratory. The design utilizes controllable geometry features to shed structural loads while maintaining a rated power over a greater number of sea states. The second-generation design will seek to provide a more refined control of performance because the first-generation design demonstrated performance reductions considered too large for smooth power output. Performance is evaluated using frequency domain analysis with consideration of a nonideal power-take-off system, with respect to power absorption, foundation loads, and power-take-off torque.

Download or read book Study of a Novel Oscillating Surge Wave Energy Converter Preprint written by and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates the performance of an oscillating surge wave energy converter (OSWEC) that utilizes adjustable geometry as a means of controlling the hydrodynamic coefficients, a concept originally proposed by [1]. The body of the device consists of a bottom-hinged solid rectangular frame with five horizontal flaps spanning the interior of the frame. The flaps can rotate independently about their center of rotation within the frame like a large window shutter. Changing the orientation of the flaps alters the hydrodynamic coefficients and natural frequency of the device as well as the ability to shed or absorb structural loads accordingly. This ability may allow the device to operate in a wider range of sea states than other current wave energy converter designs. This paper presents and compares the results of numerical simulations and experimental testing of the OSWEC's response to regular waves with all five of the horizontal fin configurations sharing the same orientation of 0 degrees (fully closed interior) and 90 degrees (fully open). The numerical simulations were performed using WAMIT, which calculates hydrodynamic coefficients using a boundary element method code to solve the linear potential flow problem, and WEC-Sim, a MATLAB-based tool that simulates multibody devices in the time domain by solving the governing equations of motion. A 1:14 scale model of the device was built for experimental evaluation in an 8-m-long, 1-m wide wave tank, which supports a water depth of 0.7 m. The OSWEC motion in different wave conditions was measured with displacement sensors while nonlinear wave-structure interaction effects like slamming and overtopping were captured using a high-speed camera and used to understand differences between the simulation and experiments.

Download or read book Design and analysis for a floating oscillating surge wave energy converter written by Y-H. Yu and published by . This book was released on 2014 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimizing Power Generation of a Bottom Raised Oscillating Surge Wave Energy Converter Using a Theoretical Model Preprint written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Preliminary sizing of an oscillating surge wave energy converter (OSWEC) is an iterative process that relies on knowledge of the relevant hydrodynamic coefficients for a given geometry. Often, the complex definition of the device geometry requires coefficients to be obtained through experiments or numerical boundary element solvers such as WAMIT. These techniques demand significant user and computational effort, therefore inhibiting the fine scale parametrization of object dimensions. In this study, a theoretical model, originally presented in Michele et al. (2016), is developed and demonstrated to efficiently optimize the power production for an OSWEC device (subjected to certain environmental conditions) with variations in device widths, heights, and distances from the seabed. Assuming negligible device thickness, the OSWEC motions are modelled as a bottom-raised two-dimensional flap in regular waves using potential flow theory formulated in elliptical coordinates. The solutions to this diffraction-radiation problem are obtained using Mathieu functions with appropriate boundary conditions. The resulting potentials are then used to derive frequency-dependent expressions for the added mass and radiation damping coefficients, along with wave excitation magnitude in surge, pitch, and coupled surge-pitch motions. Good agreement in hydrodynamic coefficient curves is shown between the theoretical model and the numerical results obtained from the boundary element-based program WAMIT. The theoretical model is then employed to maximize the time-averaged output power while maintaining or reducing the hinge reaction force, with variations in device dimensions, wave frequency and amplitude.

Download or read book Design and Analysis for a Floating Oscillating Surge Wave Energy Converter written by and published by . This book was released on 2014 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a recent study on the design and analysis of an oscillating surge wave energy converter. A successful wave energy conversion design requires the balance between the design performance and cost. The cost of energy is often used as the metric to judge the design of the wave energy conversion system. It is often determined based on the device power performance, the cost for manufacturing, deployment, operation and maintenance, as well as the effort to ensure the environmental compliance. The objective of this study is to demonstrate the importance of a cost driven design strategy and how it can affect a WEC design. Three oscillating surge wave energy converter (OSWEC) designs were used as the example. The power generation performance of the design was modeled using a time-domain numerical simulation tool, and the mass properties of the design were determined based on a simple structure analysis. The results of those power performance simulations, the structure analysis and a simple economic assessment were then used to determine the cost-efficiency of selected OSWEC designs. Finally, a discussion on the environmental barrier, integrated design strategy and the key areas that need further investigation is also presented.

Download or read book Design and Analysis for a Floating Oscillating Surge Wave Energy Converter written by Y-H. Yu and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Submerged Pressure Differential Plate Wave Energy Converter with Variable Geometry written by Nathan Tom and published by . This book was released on 2019 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design of a Two Body Wave Energy Converter Featuring Controllable Geometry Preprint written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: While the field of wave energy has been the subject of numerical simulation, scale model testing, and precommercial project testing for decades, wave energy technologies remain in the early stages of development and must continuing proving themselves as a promising modern renewable energy field. A wave energy converter (WEC) concept, currently being explored, is hoping to add an extra control option to WEC design is the variable-geometry WEC (VGWEC). These VGWECs attempt to incorporate controllable geometric features to adjust the floating body hydrodynamics to favor either power absorption, load shedding, or other operational goals. These variable geometry components have been proposed to be controlled on a sea-state-to-sea-state or wave-to-wave time scale depending on the force (or toque) and bandwidth limitations of the actuators required to manipulate just the controllable geometric hull features. The opportunities of having control over both the WEC geometry components and the power-take-off (PTO) have the potential to improve overall system performance and reliability if a cost-effective solution can be found for a given WEC architecture. This paper will present the recent developments and results of a VGWEC concept that incorporates variable geometry modules into a two-body WEC. In the proposed VGWEC concept, the variable geometry modules consist of air inflatable bags in the surface float and a water inflatable ring in the subsurface body. The surface float is tethered directly to the subsurface body through tether lines each connected to a separate PTO. Adjusting the geometry of both the surface and subsurface bodies along with the PTO coefficients can be shown to maximize power in design sea states while reducing motion response and PTO forces when transitioning to sea states where rated power is reached and load shedding is prioritized in hopes of increasing the sea state operational map.

Download or read book Numerical Modelling of Wave Energy Converters written by Matt Folley and published by Academic Press. This book was released on 2016-06-14 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical Modelling of Wave Energy Converters: State-of-the Art Techniques for Single WEC and Converter Arrays presents all the information and techniques required for the numerical modelling of a wave energy converter together with a comparative review of the different available techniques. The authors provide clear details on the subject and guidance on its use for WEC design, covering topics such as boundary element methods, frequency domain models, spectral domain models, time domain models, non linear potential flow models, CFD models, semi analytical models, phase resolving wave propagation models, phase averaging wave propagation models, parametric design and control optimization, mean annual energy yield, hydrodynamic loads assessment, and environmental impact assessment. Each chapter starts by defining the fundamental principles underlying the numerical modelling technique and finishes with a discussion of the technique’s limitations and a summary of the main points in the chapter. The contents of the chapters are not limited to a description of the mathematics, but also include details and discussion of the current available tools, examples available in the literature, and verification, validation, and computational requirements. In this way, the key points of each modelling technique can be identified without having to get deeply involved in the mathematical representation that is at the core of each chapter. The book is separated into four parts. The first two parts deal with modelling single wave energy converters; the third part considers the modelling of arrays; and the final part looks at the application of the different modelling techniques to the four most common uses of numerical models. It is ideal for graduate engineers and scientists interested in numerical modelling of wave energy converters, and decision-makers who must review different modelling techniques and assess their suitability and output. Consolidates in one volume information and techniques for the numerical modelling of wave energy converters and converter arrays, which has, up until now, been spread around multiple academic journals and conference proceedings making it difficult to access Presents a comparative review of the different numerical modelling techniques applied to wave energy converters, discussing their limitations, current available tools, examples, and verification, validation, and computational requirements Includes practical examples and simulations available for download at the book’s companion website Identifies key points of each modelling technique without getting deeply involved in the mathematical representation

Download or read book Ocean Wave Energy Conversion written by Aurelien Babarit and published by Elsevier. This book was released on 2017-11-17 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Handbook of Ocean Wave Energy written by Arthur Pecher and published by Springer. This book was released on 2016-12-07 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is open access under a CC BY-NC 2.5 license. This book offers a concise, practice-oriented reference-guide to the field of ocean wave energy. The ten chapters highlight the key rules of thumb, address all the main technical engineering aspects and describe in detail all the key aspects to be considered in the techno-economic assessment of wave energy converters. Written in an easy-to-understand style, the book answers questions relevant to readers of different backgrounds, from developers, private and public investors, to students and researchers. It is thereby a valuable resource for both newcomers and experienced practitioners in the wave energy sector.

Download or read book Ocean Wave Energy written by Joao Cruz and published by Springer Science & Business Media. This book was released on 2007-12-22 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors of this timely reference provide an updated and global view on ocean wave energy conversion – and they do so for wave energy developers as well as for students and professors. The book is orientated to the practical solutions that this new industry has found so far and the problems that any device needs to face. It describes the actual principles applied to machines that convert wave power to electricity and examines state-of-the-art modern systems.

Download or read book Energy Harvesting written by Alireza Khaligh and published by CRC Press. This book was released on 2017-12-19 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: Also called energy scavenging, energy harvesting captures, stores, and uses "clean" energy sources by employing interfaces, storage devices, and other units. Unlike conventional electric power generation systems, renewable energy harvesting does not use fossil fuels and the generation units can be decentralized, thereby significantly reducing transmission and distribution losses. But advanced technical methods must be developed to increase the efficiency of devices in harvesting energy from environmentally friendly, "green" resources and converting them into electrical energy. Recognizing this need, Energy Harvesting: Solar, Wind, and Ocean Energy Conversion Systems describes various energy harvesting technologies, different topologies, and many types of power electronic interfaces for stand-alone utilization or grid connection of energy harvesting applications. Along with providing all the necessary concepts and theoretical background, the authors develop simulation models throughout the text to build a practical understanding of system analysis and modeling. With a focus on solar energy, the first chapter discusses the I−V characteristics of photovoltaic (PV) systems, PV models and equivalent circuits, sun tracking systems, maximum power point tracking systems, shading effects, and power electronic interfaces for grid-connected and stand-alone PV systems. It also presents sizing criteria for applications and modern solar energy applications, including residential, vehicular, naval, and space applications. The next chapter reviews different types of wind turbines and electrical machines as well as various power electronic interfaces. After explaining the energy generation technologies, optimal operation principles, and possible utilization techniques of ocean tidal energy harvesting, the book explores near- and offshore approaches for harvesting the kinetic and potential energy of ocean waves. It also describes the required absorber, turbine, and generator types, along with the power electronic interfaces for grid connection and commercialized ocean wave energy conversion applications. The final chapter deals with closed, open, and hybrid-cycle ocean thermal energy conversion systems.

Download or read book Renewable Energy in Marine Environment written by Eugen Rusu and published by MDPI. This book was released on 2020-03-25 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of human-caused global warming are obvious, requiring new strategies and approaches. The concept of business-as-usual is now no longer beneficial. Extraction of renewable energy in marine environments represents a viable solution and an important path for the future. These huge renewable energy resources in seas and oceans can be harvested, including wind, tide, and waves. Despite the initial difficulties related mostly to the elevated operational risks in the harsh marine environment, newly developed technologies are economically effective or promising. Simultaneously, many challenges remain to be faced. These are the main issues targeted by the present book, which is associated with the Special Issue of Energies Journal entitled “Renewable Energy in Marine Environment”. Papers on innovative technical developments, reviews, case studies, and analytics, as well as assessments, and papers from different disciplines that are relevant to the topic are included. From this perspective, we hope that the results presented are of interest to for scientists and those in related fields such as energy and marine environments, as well as for a wider audience.

Download or read book Building Industries at Sea Blue Growth and the New Maritime Economy written by Kate Johnson and published by CRC Press. This book was released on 2022-09-01 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout the world there is evidence of mounting interest in marine resources and new maritime industries to create jobs, economic growth and to help in the provision of energy and food security. Expanding populations, insecurity of traditional sources of supply and the effects of climate change add urgency to a perceived need to address and overcome the serious challenges of working in the maritime environment. Four promising areas of activity for ‘Blue Growth’ have been identified at European Union policy level including Aquaculture; Renewable Energy (offshore wind, wave and tide); Seabed Mining; and Blue Biotechnology. Work has started to raise the technological and investment readiness levels (TRLs and IRLs) of these prospective industries drawing on the experience of established maritime industries such as Offshore Oil and Gas; Shipping; Fisheries and Tourism. An accord has to be struck between policy makers and regulators on the one hand, anxious to direct research and business incentives in effective and efficient directions, and developers, investors and businesses on the other, anxious to reduce the risks of such potentially profitable but innovative investments.The EU H2020 MARIBE (Marine Investment for the Blue Economy) funded project was designed to identify the key technical and non-technical challenges facing maritime industries and to place them into the social and economic context of the coastal and ocean economy. MARIBE went on to examine with companies, real projects for the combination of marine industry sectors into multi-use platforms (MUPs). The purpose of this book is to publish the detailed analysis of each prospective and established maritime business sector. Sector experts working to a common template explain what these industries are, how they work, their prospects to create wealth and employment, and where they currently stand in terms of innovation, trends and their lifecycle. The book goes on to describe progress with the changing regulatory and planning regimes in the European Sea Basins including the Caribbean where there are significant European interests. The book includes:• Experienced chapter authors from a truly multidisciplinary team of sector specialisms• First extensive study to compare and contrast traditional Blue Economy with Blue Growth• Complementary to EU and National policies for multi-use of maritime space

Download or read book Wave Energy Conversion written by John Brooke and published by Elsevier. This book was released on 2003-09-26 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave energy, together with other renewable energy resources is expected to provide a small but significant proportion of future energy requirements without adding to pollution and global warming. This practical and concise reference considers alternative application methods, explains the concepts behind wave energy conversion and investigates wave power activities across the globe. Explores the potential of using the power generated by waves as a natural energy resource Considers the power transfer systems needed to do this, and looks at the environmental impacts