Download or read book PERFORMANCE OF A NEAR SHORE OSCILLATING WAVE SURGE CONVERTER WITH VARIABLE FLAP CONFIGURATIONS written by Landon Sugar and published by . This book was released on 2021 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most oscillating wave surge converters (OWSCs) are designed to enter survival mode during energetic wave conditions where they forego the opportunity to extract energy in an attempt to preserve structural integrity. While this is a good tradeoff, it is important that OWSC technology progresses to a point where energy is constantly extracted when waves are present. The OWSC studied here is a variation of a device that was conceptually designed and patented by researchers at the National Renewable Energy Laboratory (NREL) and consists of multiple adjustable vanes that, when opened, allow some of the wave force to pass through the device. Currently, NREL's investigations have been limited to a single OWSC consisting of 4 and 5 adjustable vanes. Therefore, there exists a need to further investigate the performance of this nearshore variable geometry OWSC in various arrangements and configurations. This research analyzes the hydrodynamic response of a 2-vane OWSC, a 4-vane OWSC, and an array of OWSCs in a frequency-domain code, a 2-vane OWSC's power generation capabilities in a wide range of sea states in a time-domain wave energy converter simulation tool, and a fluid flow analysis of the 2-vane OWSC in standard and energetic sea states using computational fluid dynamics (CFD). It was hypothesized that opening the vane angles would significantly and consistently reduce the OWSC's hydrodynamic response to various wave frequencies, its power production capabilities, its oscillatory motions, and the potential for wave slamming. The frequency- and time-domain results indicated that most configurations had consistent and predictable responses, while other configurations were more sensitive to the vane angle changes. The CFD results indicated that opening the vanes led to a reduction in wave slamming. However, the fluid flow became highly unpredictable as the vane angles changed, resulting in incident wave damping, inconsistent OWSC oscillations, and hydraulic jump formation.
Download or read book Ocean Waves and Oscillating Systems written by Johannes Falnes and published by Cambridge University Press. This book was released on 2020-05-28 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understand the absorption of energy from ocean waves by means of oscillating systems with this useful new edition. Essential for engineers, researchers, and graduate students, and an indispensable tool for those who work in this field.
Download or read book Power from Waves written by M. H. Osterried and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Fourth International Conference in Ocean Engineering ICOE2018 written by K. Murali and published by Springer. This book was released on 2018-12-31 with total page 929 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises selected proceedings of the Fourth International Conference in Ocean Engineering (ICOE2018), focusing on emerging opportunities and challenges in the field of ocean engineering and offshore structures. It includes state-of-the-art content from leading international experts, making it a valuable resource for researchers and practicing engineers alike.
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 Numerical Modeling of an Oscillating Wave Surge Converter Subjected to Regular and Irregular Waves written by Hejar Jebeli Aqdam and published by . This book was released on 2016 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a mathematical model based on potential flow theory to study the dynamics of a flap-type bottom-hinged surface piercing Wave Energy Converter (WEC). The model is used to study both : (a) the linear dynamics of the WEC in response to regular waves, and (b) nonlinear dynamics of the WEC in response to regular and irregular waves. Both linear and nonlinear WEC responses are validated against previous works. Using this model we conduct a parametric study over the flap width and Power Take Off (PTO) damping coefficient to seek better device performance.It is found that higher capture factors can be ensured by appropriately choosing the flap width such that both the oscillating (at resonance) and decaying portions of the capture factor curve lie in the sea spectrum. It is also found that linear response of the WEC is close to nonlinear response if the natural period of the WEC lies outside the sea spectrum. However, when the WEC's natural period does lie in side the sea spectrum, the WEC's response becomes a strong function of viscous damping coefficient. It therefore becomes important to model accurately the viscous drag.
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 Preliminary Analysis of an Oscillating Surge Wave Energy Converter with Controlled Geometry written by and published by . This book was released on 2015 with total page 12 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 Performance Modeling of a Variable geometry Oscillating Surge Wave Energy Converter on a Raised Foundation written by Cole Burge and published by . This book was released on 2021 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimentation Validation and Uncertainty Analysis for Engineers written by Hugh W. Coleman and published by John Wiley & Sons. This book was released on 2018-04-09 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helps engineers and scientists assess and manage uncertainty at all stages of experimentation and validation of simulations Fully updated from its previous edition, Experimentation, Validation, and Uncertainty Analysis for Engineers, Fourth Edition includes expanded coverage and new examples of applying the Monte Carlo Method (MCM) in performing uncertainty analyses. Presenting the current, internationally accepted methodology from ISO, ANSI, and ASME standards for propagating uncertainties using both the MCM and the Taylor Series Method (TSM), it provides a logical approach to experimentation and validation through the application of uncertainty analysis in the planning, design, construction, debugging, execution, data analysis, and reporting phases of experimental and validation programs. It also illustrates how to use a spreadsheet approach to apply the MCM and the TSM, based on the authors’ experience in applying uncertainty analysis in complex, large-scale testing of real engineering systems. Experimentation, Validation, and Uncertainty Analysis for Engineers, Fourth Edition includes examples throughout, contains end of chapter problems, and is accompanied by the authors’ website www.uncertainty-analysis.com. Guides readers through all aspects of experimentation, validation, and uncertainty analysis Emphasizes the use of the Monte Carlo Method in performing uncertainty analysis Includes complete new examples throughout Features workable problems at the end of chapters Experimentation, Validation, and Uncertainty Analysis for Engineers, Fourth Edition is an ideal text and guide for researchers, engineers, and graduate and senior undergraduate students in engineering and science disciplines. Knowledge of the material in this Fourth Edition is a must for those involved in executing or managing experimental programs or validating models and simulations.
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 Numerical and Experimental Modelling of an Oscillating Wave Surge Converter in Partially Standing Wave Systems written by Bryce Bocking and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the field of ocean wave energy converters (WECs), active areas of research are on a priori or in situ methods for power production estimates and on control system design. Linear potential flow theory modelling techniques often underpin these studies; however, such models rely upon small wave and body motion amplitude assumptions and therefore cannot be applied to all wave conditions. Nonlinear extensions can be applied to the fluid loads upon the structure to extend the range of wave conditions for which these models can provide accurate predictions. However, careful consideration of the thresholds of wave height and periods to which these models can be applied is still required. Experimental modelling in wave tank facilities can be used for this purpose by comparing experimental observations to numerical predictions using the experimental wave field as an input. This study establishes a recommended time domain numerical modeling approach for power production assessments of oscillating wave surge converters (OWSCs), a class of WEC designed to operate in shallow and intermediate water depths. Three candidate models were developed based on nonlinear numerical modelling techniques in literature, each with varying levels of complexity. Numerical predictions provided by each model were found to be very similar for small wave amplitudes, but divergence between the models was observed as wave height increased. Experimental data collected with a scale model OWSC for a variety of wave conditions was used to evaluate the accuracy of the candidate models. These experiments were conducted in a small-scale wave flume at the University of Victoria. A challenge with this experimental work was managing wave reflections from the boundaries of the tank, which were significant and impacted the dynamics of the scale model OWSC. To resolve this challenge, a modified reflection algorithm based upon the Mansard and Funke method was created to identify the incident and reflected wave amplitudes while the OWSC model is in the tank. Both incident and reflected wave amplitudes are then input to the candidate models to compare numerical predictions with experimental observations. The candidate models agreed reasonably well with the experimental data, and demonstrated the utility of the modified wave reflection algorithm for future experiments. However, the maximum wave height generated in the wave tank was found to be limited by the stroke length of the wavemaker. As a result, no significant divergence of the candidate model predictions from the experimental data could be observed for the limited range of wave conditions, and therefore a recommended model could not be selected based solely on the experimental/numerical model comparisons. Preliminary assessments of the annual power production (APP) for the OWSC were obtained for a potential deployment site on the west coast of Vancouver Island. Optimal power take-off (PTO) settings for the candidate models were identified using a least-squares optimization to maximize power production for a given set of wave conditions. The power production of the OWSC at full scale was then simulated for each bin of a wave histogram representing one year of sea states at the deployment site. Of the three candidate models, APP estimates were only obtained for Model 1, which has the lowest computational requirements, and Model 3, which implements the most accurate algorithm for computing the fluid loads upon the OWSC device. Model 2 was not considered as it provides neither advantages of Models 1 and 3. The APP estimates from Models 1 and 3 were 337 and 361 MWh per year. For future power production assessments, Model 3 is recommended due to its more accurate model of the fluid loads upon the OWSC. However, if the high computational requirements of Model 3 are problematic, then Model 1 can be used to obtain a slightly conservative estimate of APP with a much lower computational effort.
Download or read book Numerical Modelling of Oscillating Wave Surge Converters Operating in Array Configurations written by Daniela Andrea Benites Muñoz and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OpenFOAM written by J. Miguel Nóbrega and published by Springer. This book was released on 2019-01-24 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains selected papers of the 11th OpenFOAM® Workshop that was held in Guimarães, Portugal, June 26 - 30, 2016. The 11th OpenFOAM® Workshop had more than 140 technical/scientific presentations and 30 courses, and was attended by circa 300 individuals, representing 180 institutions and 30 countries, from all continents. The OpenFOAM® Workshop provided a forum for researchers, industrial users, software developers, consultants and academics working with OpenFOAM® technology. The central part of the Workshop was the two-day conference, where presentations and posters on industrial applications and academic research were shown. OpenFOAM® (Open Source Field Operation and Manipulation) is a free, open source computational toolbox that has a larger user base across most areas of engineering and science, from both commercial and academic organizations. As a technology, OpenFOAM® provides an extensive range of features to solve anything from complex fluid flows involving chemical reactions, turbulence and heat transfer, to solid dynamics and electromagnetics, among several others. Additionally, the OpenFOAM technology offers complete freedom to customize and extend its functionalities.
Download or read book Assessment of a Nearshore Modular Flap type Wave Energy Converter written by Laurie Fletcher Wilkinson and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Progress in Renewable Energies Offshore written by C. Guedes Soares and published by CRC Press. This book was released on 2016-11-18 with total page 1731 pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress in Renewable Energies Offshore includes the papers presented in the 2nd International Conference on Renewable Energies Offshore (RENEW2016, Lisbon, Portugal, 24-26 October 2016). The scope of the book is broad, covering all aspects of renewable energies offshore activities such as resource assessment; wind energy; wave energy; tidal energy; ocean energy devices; multiuse platforms; PTO design; grid connection; economic assessment; installation and maintenance planning. The contents of the present book are organized in these main subject areas corresponding to the sessions in the Conference. The conference reflects the importance of the renewable energies offshore worldwide and is an opportunity to contribute to the exchange of information on the developments and experience obtained in concept development, design and operation of these devices. Progress in Renewable Energies Offshore has as main target academics and professionals working in the related areas of renewable energies.
