Download or read book Examining the Effects of Directional Wave Spectra on a Nearshore Wave Model written by Sally Catherine Davis Dillon and published by . This book was released on 2018 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave models are an integral part of coastal engineering due to their ability to quantify information that is either unobtainable or unavailable. However, these models rely heavily on their directional wave spectrum inputs which describe the variation of energy in frequency and direction. This study investigated how five methods for computing the directional wave spectrum perform within the nearshore wave model, STWAVE. The results of the five runs showed that overall, the greatest differences between spectra were observed in the significant wave height parameter. The mean wave direction showed greater differences at the offshore model domain boundary and lesser differences as the wave enters the nearshore; and the peak period had fewer differences at the boundary, but at the nearshore the differences were dependent upon the presence of wind forcing. Winds had a significant impact on observed differences between the spectra in the domain by dominating the wave field variation.
Download or read book Examining the Effects of Directional Wave Spectra on a Nearshore Wave Model written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave models are an integral part of coastal engineering due to their ability to quantify information that is either unobtainable or unavailable. However, these models rely heavily on the input of a directional wave spectrum that describes the variation of energy with frequency and direction. This study investigated how five methods for computing the directional wave spectrum perform within the nearshore spectral wave model, STWAVE. The results of the five experimental runs showed that overall, the greatest differences between spectra were observed in the significant wave height parameter. The mean wave direction showed greater differences at the offshore model domain boundary and lesser differences as the wave enters the nearshore; and the peak period had fewer differences at the boundary, but at the nearshore the differences were dependent upon the presence of wind forcing. Winds had a significant impact on observed differences between the spectra in the domain by dominating the wave field variation.
Download or read book Advances in Coastal and Ocean Engineering written by Philip L. F. Liu and published by World Scientific Publishing Company Incorporated. This book was released on 1995 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the Earth's surface is covered by water. Many aspects of our everyday lives and activities may be affected by water waves in some way. Sometimes, the waves can cause disaster. One of the examples was the tsunami that occurred in the Indian Ocean on 26 December 2004. This indicates how important it is for us to fully understand water waves, in particular the very large ones. One way to do so is to perform numerical simulation based on the nonlinear theory. Considerable research advances have been made in this area over the past decade by developing various numerical methods and applying them to emerging problems: however, until now there has been no comprehensive book to reflect these advances. This unique volume aims to bridge this gap.
Download or read book On the Nearshore Impact of Wave Energy Converter Arrays written by Annika Magnuson O'Dea and published by . This book was released on 2014 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation stresses, defined as the excess flow of momentum due to the presence of waves (Longuet-Higgins, 1964), are the main drivers behind the cross-shore and longshore forcing that results in wave setup, set-down, and longshore currents (e.g. Svendsen, 2006). Longshore currents entrain and transport sediment and therefore play an important role in short- and long-term coastal evolution (Komar, 1998). Due to their importance in many nearshore processes, quantifying and analyzing nearshore radiation stresses is often an important component of coastal engineering and management projects. This thesis presents two manuscripts focusing on radiation stress in nearshore zones. The first manuscript describes a methodology for assessing the nearshore impacts of the presence of Wave Energy Converter (WEC) arrays based on the net change in the alongshore radiation stress gradients shoreward of the array. First, a threshold for nearshore hydrodynamic impact is established based on the observed relationship between nearshore radiation stress and the maximum alongshore current velocity in past field studies. A parametric study is then conducted on an idealized beach using the spectral model SWAN to analyze nearshore impact using a range of array configurations, locations, and incident wave conditions. WEC devices are represented in SWAN through the external modification of the wave spectra at the device location using an experimentally determined power transfer function. In the final section, the same methodology is applied to two wave energy test sites off the coast of Oregon to assess the applicability of the conclusions made in the parametric study to sites with more complicated bathymetries. Although the changes in wave height, wave direction, and cross-shore force in the lee of the array are similar to the changes seen in the parametric study, the changes in longshore radiation stress forcing are more heavily influenced by local bathymetry. The second manuscript examines how the total radiation stress is affected by directional asymmetry in the incident wave spectrum. The process of wave refraction in nearshore zones results in an asymmetric directional distribution of spectral energy when oblique, multi-directional wave fields propagate into shallow water areas with limited alongshore variability. In this study, net radiation stresses are calculated using a JONSWAP frequency spectrum with both symmetric and asymmetric directional spreading functions and then compared to those calculated from the monochromatic formulation. Because information on the full frequency and directional distribution of spectral energy is not always available in practice, the monochromatic formulation is often used as an approximation of the true radiation stress. Past studies have demonstrated that the use of the monochromatic approximation in radiation stress calculations results in a significant overestimation of the radiation stress components S[subscript xx] and S[subscript xy] in broad-banded seas. The present results show that the inclusion of directional asymmetry in radiation stress calculations reduces the difference between the full spectral S[subscript xx] and the monochromatic approximation but increases the difference between the full spectral S[subscript xy] and the monochromatic approximation for a range of dominant wave directions. The use of a monochromatic approximation of S[subscript xy] can therefore lead to an overestimation of the actual radiation stress in certain sea states and consequently an overestimation of associated parameters such as alongshore current velocities and alongshore sediment transport rates.
Download or read book Directional Ocean Wave Spectra written by Robert C. Beal and published by . This book was released on 1991 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Das Buch enthält insgesamt 33 Vorträge, die anlässlich des Symposiums "Measuring, Modeling, Predicting, and Applying Directional Ocean Wave Spectra" gehalten wurden, welches von 19890418 bis 19890420 am Applied Physics Laboratory der Johns Hopkins Universität stattfand. Das Symposium war den Ergebnissen des Labrador Sea Extreme Waves Experiment (LEWEX) gewidmet, welches mit internationaler Beteiligung unter Einsatz von zwei Schiffen, zwei Radar- Fernerkundungsflugzeugen sowie Radar-Fernerkundungssatelliten im März 1987 in der Labradorsee durchgeführt wurde. Ziel war die Bestimmung von richtungsbezogenen Meereswellenspektren. Nach zwei einführenden Vorträgen in das Experiment LEWEX sowie in die Bedeutung der Wellenspektren widmen sich die übrigen Fachbeiträge folgenden Themen: Physik von Wind und Wellen (Wind-Wave Physics); Seegangsverhalten und Messungen an der Meeresoberfläche (Seakeeping and Surface Measurement); Luftgestützte und weltraumgestützte Radarmessungen (Air and Space Measurement); Numerische Modellrechnungen (Numerical Model Estimates); Zukünftiger Forschungsbedarf (Future Directions). 300 der während LEWEX gemessenen 2000 Wellenspektren werden vorgestellt und verglichen.
Download or read book Applied Aerodynamics written by Jorge Colman Lerner and published by BoD – Books on Demand. This book was released on 2012-05-11 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamics, from a modern point of view, is a branch of physics that study physical laws and their applications, regarding the displacement of a body into a fluid, such concept could be applied to any body moving in a fluid at rest or any fluid moving around a body at rest. This Book covers a small part of the numerous cases of stationary and non stationary aerodynamics; wave generation and propagation; wind energy; flow control techniques and, also, sports aerodynamics. It's not an undergraduate text but is thought to be useful for those teachers and/or researchers which work in the several branches of applied aerodynamics and/or applied fluid dynamics, from experiments procedures to computational methods.
Download or read book Measuring and analysing the directional spectra of ocean waves written by COST Action 714 and published by . This book was released on 2005 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Wave Modeling written by The SWAMP Group and published by Springer Science & Business Media. This book was released on 2013-11-22 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early in 1979, a group of wave researchers proposed a wave model inter comparison study to clarify the interrelations existing among the various wave models which have been developed in past years for real-time wave forecasting, wave statistics compilations, or hindcast case studies. The idea was immediately welcomed by the wave modeling community, and, finally, nine wave modeling groups from the United States, Japan, and Europe participated in the exercise. The principal results of this work are presented here jointly by the Sea Wave Modeling Project (swAMP) Group (the members of which are listed in Appendix A). Descriptions of the models used in the study are given in Part II of this volume. A more complete documentation of the entire set of numerical experiments is given in Part 2 of the Sea Wave Modeling Project (SWAMP group, 1982). The main purpose of the intercomparison study was to test our present understanding of the physics of . wind-generated surface waves from the viewpoint of wave modeling. Specifically, we wished to clarify the basic interdependence between understanding the physics of surface waves, repre senting the physics numerically, and predicting quantitatively the detailed space-time evolution of a two-dimensional surface wave spectrum for a given wind field. It was not our intent to carry out a model competition. In this sense there were no winners or losers: all models could claim specific strong points, and all displayed weaknesses in some areas.
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 Directional Spectral Wave Transformation in the Nearshore Region written by Michael Jeffrey Briggs and published by . This book was released on 1989 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Breaking Waves on the Directional Spectrum of Waves in Water of Variable Depth in the Presence of Current written by C. C. Tung and published by . This book was released on 1989 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The CERCular written by and published by . This book was released on 1988 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of Wave Self similarity in Nearshore Wave Spectra written by Morgan Menzies Smith and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlinear wave-wave interactions and wave breaking contribute to nearshore wave energy dissipation. These factors can be analyzed by the principles of wave self-similarity. The equilibrium range can be shown in wind-driven wave spectra that exist in the form ( ) and However, the appropriate methods used to determine this loss of energy are controversial. This study examines an approach that reinvestigates the self-similarity principles. Wave spectra with lower peak periods are dominated by nonlinear wave-wave interactions which produce a scaling in shallow water. This thesis investigates the relative role of spectral similarity in different conditions in the nearshore region of the U.S. Army Corps of Engineers Field Research Facility in Duck, North Carolina. The results show young sea waves (wave spectra in which the propagation speed of waves at the spectral peak is much smaller than the wind speed) are dominated by nonlinear wave-wave interactions in the nearshore while older waves (wave spectra in which the propagation speed of waves at the spectral peak is equal to or greater than the wind speed) are dominated by wave breaking in deep water. Furthermore, nearshore wave models need to incorporate the self-similarity concept in deep and shallow water to better understand and quantify important aspects of wave physics in shallow water.
Download or read book Waves in Oceanic and Coastal Waters written by Leo H. Holthuijsen and published by Cambridge University Press. This book was released on 2010-02-04 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Waves in Oceanic and Coastal Waters describes the observation, analysis and prediction of wind-generated waves in the open ocean, in shelf seas, and in coastal regions with islands, channels, tidal flats and inlets, estuaries, fjords and lagoons. Most of this richly illustrated book is devoted to the physical aspects of waves. After introducing observation techniques for waves, both at sea and from space, the book defines the parameters that characterise waves. Using basic statistical and physical concepts, the author discusses the prediction of waves in oceanic and coastal waters, first in terms of generalised observations, and then in terms of the more theoretical framework of the spectral energy balance. He gives the results of established theories and also the direction in which research is developing. The book ends with a description of SWAN (Simulating Waves Nearshore), the preferred computer model of the engineering community for predicting waves in coastal waters.
Download or read book Comparison of Measured and Transformed Directional Wave Spectra Using a Linear Refraction Model written by James Cheng Liu and published by . This book was released on 1990 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean Wave Dynamics For Coastal And Marine Structures written by Vallam Sundar and published by World Scientific. This book was released on 2021-07-05 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increase in exploration and exploitation of ocean resources, maritime trade and ocean energy have led to development of new concepts in the study of coastal and marine structures. These developments necessitate comprehensive and in-depth knowledge of ocean wave behavior in the offshore as well as in the nearshore, such as the phenomena of wave generation, propagation, deformation and its effects, which help to enlighten our understanding of its influence on coastal and offshore structures.Ocean Wave Dynamics for Coastal and Marine Structures is a recommended textbook for students and researchers in ocean sciences, engineering and related topics. It offers application of theoretical formulae to practical relevance through problem solving. This book will also be invaluable for professionals in ports, offshore and marine industries as well as consulting companies.
Download or read book Three parameter Characterization of Shallow water Directional Wind Wave Spectra written by Charles E. Long and published by . This book was released on 1994 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:
