Download or read book A Mixing Mechanism in the Nearshore Region written by Uday Putrevu and published by . This book was released on 1994 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nearshore Currents Over a Barred Beach written by Antonio Fernando Garcez Faria and published by . This book was released on 1997 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this dissertation is to develop numerical models and compare their predictions with data acquired during the DUCK94 experiment in order to improve our physical understanding of the hydrodynamic processes governing the vertical and cross shore distributions of both longshore and cross shore currents over a barred beach. The vertical structure of the mean longshore current is found to be well described by a logarithmic profile and a relationship between bed shear stress and bottom roughness, including the influence of ripples and mega-ripples, was also found. The vertical structure of the mean cross shore current (undertow) is modeled using an eddy viscosity closure scheme to solve for the turbulent shear stress and includes contributions from breaking wave rollers. These models of the vertical profiles of longshore and cross shore mean currents are combined to formulate a quasi three dimensional model to describe the cross shore distribution of the longshore current. This model includes turbulent mixing due to the cross shore advection of mean momentum of the longshore current by the mean cross shore current and contributions from wave rollers.
Download or read book A Simple Quasi three Dimensional Model of Longshore Currents Over Arbitrary Profile written by Antonio Fernando Garcez Faria and published by . This book was released on 1995 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long shore current maximum observed in the trough of a barred beach during the nearshore dynamics experiment DELILAH at Duck, North Carolina, is not predicted by present theory. The simplest longshore curren models balance cross-shore changes in the alongshore wave momentum (radiation stress) with the alongshore bottom shear stress. Waves break over the bar, reform in the trough and again break on the foreshore resulting in changes in the radiation stress, which predicts two jets, one over the bar and the other at the foreshore, which does not agree with the observed current maximum in the trough. The advection of the momentum of the longshore current by mean cross-shore currents as a source of momentum mixing is investigated. The longshore current is strongest toward the surface and decreasing to zero at the bottom. The cross-shore mean current has an onshore transport in the wave crest/trough region and an offshore transport beneath (undertow). The net interaction can induce significant lateral mixing of the alongshore momentum of the mean currents, which is shown using a simplified three- dimension model of nearshore currents to explain much of the differences with observations.
Download or read book NMLONG written by Magnus Larson and published by . This book was released on 2002 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Topics in Longshore Currents written by John Casey Church and published by . This book was released on 1993 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The momentum equation governing mean longshore currents on straight beaches is a balance of forcing from the momentum transfer of the oscillatory wave motion, turbulent momentum transfer (mixing), and bottom stress. Of these, the wave's contribution is well understood, but the remaining two are not, principally due to the complicated hydrodynamics of the surf-zone. Addressing the bottom stress term, a longshore current model is developed which includes a modification of the bottom stress due to the effects of breaking-wave induced turbulence. A one-dimensional turbulent kinetic energy equation is used to model this breaking-wave induced turbulence, producing a spatially varying bottom friction coefficient. The modeled longshore current cross-shore profiles show improved agreement with field observations. In a second bottom stress study, vertical profiles of mean longshore currents are examined using field data obtained with vertically stacked electromagnetic current meters with the goal of measuring the bottom stress and its associated drag coefficient. The profiles are observed to become vertically uniform whenever the ratio of wave height to depth exceeds 0.3, indicating that nearly all of the waves passing a given location are breaking. Finally, horizontal turbulent momentum transfer (mixing) is examined for the case of shear instabilities of the longshore current.
Download or read book Coastal Processes with Engineering Applications written by Robert G. Dean and published by Cambridge University Press. This book was released on 2004-03-25 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Text on coastal engineering and oceanography covering theory and applications intended to mitigate shoreline erosion.
Download or read book Advances In Coastal And Ocean Engineering Vol 2 written by Philip L-f Liu and published by World Scientific. This book was released on 1996-07-03 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains six papers discussing coastal processes, and physical and numerical modeling.In the first paper, Svendsen and Putrevu give an extensive review on the state of understanding of surf-zone hydrodynamics, including subjects such as wave breaking, wave-induced currents, and instability of nearshore currents and infragravity waves. They point out that the most urgent need is to develop an adequate theory for wave breaking and broken waves in the surf zone.One of the methods for studying the complex coastal processes is to perform laboratory experiments. However, physical models are always plagued by scale and laboratory effects, because the coastal process involves many different length and time scales. In the second paper, Kamphuis presents a detailed discussion on the sources and implications of the scale and laboratory effects on physical modeling.The third and the fourth papers are two parts of the discussion on the mathematical modeling of the meso-tidal barrier island coasts. To understand the dynamics of coastal inlet systems, one can either rely on empirical knowledge and construct various forms of empirical and semi-empirical models (Part I), or develop a set of mathematical models based on the physical processes (Part II). Although these models do not provide the details of the dynamics, they give valuable knowledge of the equilibrium-state relationships. de Vriend and Ribberink give a detailed review on two models, Initial Sedimentation/Erosion models and Medium-Term Morphodynamic models. They have also presented many examples of applications.In the fifth paper, Houston gives a brief review on different methods to mitigate beach loss caused by storms or persistent long-term erosion. He then describes, in detail, the method of beach nourishment, which is also called a beach fill. This paper discusses the information that must be collected to design a beach fill and that should be monitored after the completion of the project.The last paper of this volume shifts our attention to the design of offshore structures, such as gravity structures, floating barges and tankers. Chakrabarti discusses the effects of the uniform and shear currents on fixed and floating structures.
Download or read book Miscellaneous Report Coastal Engineering Research Center written by Coastal Engineering Research Center (U.S.) and published by . This book was released on 1976 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Coastal and Ocean Engineering written by Philip L. F. Liu and published by World Scientific. This book was released on 1996 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains six papers discussing coastal processes, and physical and numerical modeling.In the first paper, Svendsen and Putrevu give an extensive review on the state of understanding of surf-zone hydrodynamics, including subjects such as wave breaking, wave-induced currents, and instability of nearshore currents and infragravity waves. They point out that the most urgent need is to develop an adequate theory for wave breaking and broken waves in the surf zone.One of the methods for studying the complex coastal processes is to perform laboratory experiments. However, physical models are always plagued by scale and laboratory effects, because the coastal process involves many different length and time scales. In the second paper, Kamphuis presents a detailed discussion on the sources and implications of the scale and laboratory effects on physical modeling.The third and the fourth papers are two parts of the discussion on the mathematical modeling of the meso-tidal barrier island coasts. To understand the dynamics of coastal inlet systems, one can either rely on empirical knowledge and construct various forms of empirical and semi-empirical models (Part I), or develop a set of mathematical models based on the physical processes (Part II). Although these models do not provide the details of the dynamics, they give valuable knowledge of the equilibrium-state relationships. de Vriend and Ribberink give a detailed review on two models, Initial Sedimentation/Erosion models and Medium-Term Morphodynamic models. They have also presented many examples of applications.In the fifth paper, Houston gives a brief review on different methods to mitigate beach loss caused by storms or persistent long-term erosion. He then describes, in detail, the method of beach nourishment, which is also called a beach fill. This paper discusses the information that must be collected to design a beach fill and that should be monitored after the completion of the project.The last paper of this volume shifts our attention to the design of offshore structures, such as gravity structures, floating barges and tankers. Chakrabarti discusses the effects of the uniform and shear currents on fixed and floating structures.
Download or read book Two dimensional Depth averaged Circulation Model CMS M2D written by and published by . This book was released on 2006 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oceanographic processes linking nearshore continental shelf and shelf break written by Kuoping Chiang and published by Frontiers Media SA. This book was released on 2023-02-27 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EPA 600 9 written by and published by . This book was released on 1976-07 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Conference on Environmental Modeling and Simulation April 19 22 1976 Cincinnati Ohio written by Wayne R. Ott and published by . This book was released on 1976 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Global Coastal Ocean Regional Studies and Syntheses written by Kenneth H. Brink and published by Harvard University Press. This book was released on 2005 with total page 1096 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microplastics in African and Asian Environments written by Johnbosco C. Egbueri and published by Springer Nature. This book was released on with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coastal Engineering 2006 written by Jane McKee Smith and published by . This book was released on 2007 with total page 1188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Power Cooling Water System Disaster Causing Organisms Outbreak and Aggregation Mechanisms Early warning Monitoring Prevention and Control written by Huang Honghui and published by Frontiers Media SA. This book was released on 2023-07-04 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:
