Nearshore Currents Over a Barred Beach

Nearshore Currents Over a Barred Beach PDF Author: Antonio Fernando Garcez Faria
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 182

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Book Description
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.

Nearshore Currents Over a Barred Beach

Nearshore Currents Over a Barred Beach PDF Author: Antonio Fernando Garcez Faria
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 182

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Book Description
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.

Introduction to Coastal Processes and Geomorphology

Introduction to Coastal Processes and Geomorphology PDF Author: Robin Davidson-Arnott
Publisher: Cambridge University Press
ISBN: 1108424279
Category : Nature
Languages : en
Pages : 541

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Book Description
Grounded in current research, this second edition has been thoroughly updated, featuring new topics, global examples and online material. Written for students studying coastal geomorphology, this is the complete guide to the processes at work on our coastlines and the features we see in coastal systems across the world.

Mechanics Of Coastal Sediment Transport

Mechanics Of Coastal Sediment Transport PDF Author: Jorgen Fredsoe
Publisher: World Scientific Publishing Company
ISBN: 9814365688
Category : Technology & Engineering
Languages : en
Pages : 390

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Book Description
This book treats the subject of sediment transport in the marine environment, covering transport of noncohesive sediment by waves and currents in- and outside the surf zone. It can be read independently, but a background in hydraulics and basic wave mechanics is required.The primary aim of the book is to describe the physical processes of sediment transport and how to represent them in mathematical models. The book can be divided in two main parts; in the first, the relevant hydrodynamic theory is described. This part contains a review of elementary theory for water waves, chapters on the turbulent wave boundary layer and the turbulent interaction between waves and currents, and finally, surf zone hydrodynamics and wave driven currents.The second part covers sediment transport and morphological development.The part on sediment transport introduces the basic concepts (critical bed shear stress, bed load, suspended load and sheet layer, near-bed concentration, effect of sloping bed); it treats suspended sediment in waves and current and in the surf zone, and current and wave-generated bed forms. Finally, the modelling of cross-shore and long-shore sediment transport is described together with the development of coastal profiles and coastlines.

Literature Review on the Geologic Aspects of Inner Shelf Cross-shore Sediment Transport

Literature Review on the Geologic Aspects of Inner Shelf Cross-shore Sediment Transport PDF Author: J. Bailey Smith
Publisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 168

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Book Description


Coastal Engineering 2004 - Proceedings Of The 29th International Conference (In 4 Vols)

Coastal Engineering 2004 - Proceedings Of The 29th International Conference (In 4 Vols) PDF Author: Jane Mckee Smith
Publisher: World Scientific
ISBN: 9814480525
Category : Science
Languages : en
Pages : 4836

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Book Description
This comprehensive and up-to-date volume contains 367 papers presented at the 29th International Conference on Coastal Engineering, held in Lisbon, Portugal, 19-24 September 2004. It is divided into five parts: waves; long waves, nearshore currents, and swash; sediment transport and morphology; coastal management, beach nourishment, and dredging; coastal structures. The contributions cover a broad range of topics including theory, numerical and physical modeling, field measurements, case studies, design, and management. Coastal Engineering 2004 provides engineers, scientists, and planners state-of-the-art information on coastal engineering and coastal processes.The proceedings have been selected for coverage in:

Coastal Dynamics '01

Coastal Dynamics '01 PDF Author: Hans Hanson
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 1110

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Book Description
This collection contains 109 papers presented at the Fourth Conference on Coastal Dynamics, held in Lund, Sweden, June 11-15, 2001.

Topics in Longshore Currents

Topics in Longshore Currents PDF Author: John Casey Church
Publisher:
ISBN:
Category : Littoral drift
Languages : en
Pages : 140

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Book Description
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.

Coastal Engineering 2008 (In 5 Volumes) - Proceedings Of The 31st International Conference

Coastal Engineering 2008 (In 5 Volumes) - Proceedings Of The 31st International Conference PDF Author: Jane Mckee Smith
Publisher: World Scientific
ISBN: 9814467561
Category : Technology & Engineering
Languages : en
Pages : 5136

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Book Description
This proceedings contains papers presented at the 31st International Conference on Coastal Engineering, which has held in Hamburg, Germany (31 August - 5 September 2008). The proceeding is divided into five parts: Waves; Long Waves, Nearshore Currents, and Swash; Sediment Transport and Morphology; Coastal Management, Environment, and Risk; and Coastal Structures. The papers cover a broad range of topics including theory, numerical and physical modeling, field measurements, case studies, design, and management. Coastal Engineering 2008 provides coastal engineers, scientists, and planners, with state-of-the-art information on coastal engineering and coastal processes.

Coastal Engineering 2002: Solving Coastal Conundrums - Proceedings Of The 28th International Conference (In 3 Vols)

Coastal Engineering 2002: Solving Coastal Conundrums - Proceedings Of The 28th International Conference (In 3 Vols) PDF Author: Jane Mckee Smith
Publisher: World Scientific
ISBN: 9814486973
Category : Technology & Engineering
Languages : en
Pages : 4007

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Book Description
This book contains more than 300 papers presented at the 28th International Conference on Coastal Engineering, held in Cardiff, Wales, in July 2002. It is divided into five parts: coastal waves; nearshore currents, swash, and long waves; coastal structures; sediment transport; and coastal morphology, beach nourishment, and coastal management. The papers cover a broad range of topics, including theory, numerical and physical modeling, field measurements, case studies, design, and management. Coastal Engineering 2002 provides engineers, scientists, and planners with state-of-the-art information on coastal engineering and coastal processes.

A Guide to Modeling Coastal Morphology

A Guide to Modeling Coastal Morphology PDF Author: Dano Roelvink
Publisher: World Scientific
ISBN: 9814304255
Category : Science
Languages : en
Pages : 291

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Book Description
Process-based morphodynamic modelling is one of the relatively new tools at the disposal of coastal scientists, engineers and managers. On paper, it offers the possibility to analyse morphological processes and to investigate the effects of various measures one might consider to alleviate some problems. For these to be applied in practice, a model should be relatively straightforward to set up. It should be accurate enough to represent the details of interest, it should run long enough and robustly to see the real effects happen, and the physical processes represented in such a way that the sediment generally goes in the right direction at the right rate. Next, practitioners must be able to judge if the patterns and outcomes of the model are realistic and finally, translate these colour pictures and vector plots to integrated parameters that are relevant to the client or end user. In a nutshell, this book provides an in-depth review of ways to model coastal processes, including many hands-on exercises.