Incorporation of Random Wave Effects Into a Quasi-3D Nearshore Circulation Model (Preprint).

Incorporation of Random Wave Effects Into a Quasi-3D Nearshore Circulation Model (Preprint). PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

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Book Description
A coupled wave-hydrodynamic modeling system, comprised of a random wave model driving a quasi-3D nearshore hydrodynamic model, is described. Random wave formulations for several inputs to the hydrodynamic model are developed. An alternate wave dissipation mechanism is incorporated into the random wave model, and two wave roller descriptions are implemented to calculate volume flux and other roller-dependent input properties. Comparison to laboratory and field data indicate that an evolving roller description, in conjunction with the 3D dispersive mixing inherent in the hydrodynamic model, yield the best results. A method to nest the model system inside larger-scale wave models is described, and an application to an area of complex bathymetry shown.

Incorporation of Random Wave Effects Into a Quasi-3D Nearshore Circulation Model (Preprint).

Incorporation of Random Wave Effects Into a Quasi-3D Nearshore Circulation Model (Preprint). PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

Get Book Here

Book Description
A coupled wave-hydrodynamic modeling system, comprised of a random wave model driving a quasi-3D nearshore hydrodynamic model, is described. Random wave formulations for several inputs to the hydrodynamic model are developed. An alternate wave dissipation mechanism is incorporated into the random wave model, and two wave roller descriptions are implemented to calculate volume flux and other roller-dependent input properties. Comparison to laboratory and field data indicate that an evolving roller description, in conjunction with the 3D dispersive mixing inherent in the hydrodynamic model, yield the best results. A method to nest the model system inside larger-scale wave models is described, and an application to an area of complex bathymetry shown.

Quasi-3D Nearshore Circulation Model SHORECIRC Version 2.0

Quasi-3D Nearshore Circulation Model SHORECIRC Version 2.0 PDF Author: Ib A. Svendsen
Publisher:
ISBN:
Category : Ocean circulation
Languages : en
Pages : 214

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Book Description


Coupling of Wave and Circulation Models for Predicting Storm-induced Waves, Surges, and Coastal Inundation

Coupling of Wave and Circulation Models for Predicting Storm-induced Waves, Surges, and Coastal Inundation PDF Author: Yunfeng Chen
Publisher:
ISBN:
Category : Ocean circulation
Languages : en
Pages :

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Book Description
The purpose of this study is to apply coupled systems for wave-current interaction for use in simulating and predicting storm-induced surges, waves and coastal inundation. Two coupled systems are used. One includes model components: ROMS (a three-dimensional ocean model) and SWAN (a third-generation numerical wave model). The other system is NearCoM (a nearshore community model) which couples SWAN and SHORECIRC (a quasi-3D nearshore circulation model). A coupled model system including ROMS and SWAN is based on MCT implementation. It is applied to Delaware Bay for wave and current simulation. The computational domain is a regional ocean scale domain covering the entire Delaware Bay and adjacent shelf region. Numerical results from the coupled system are compared with available wave and current data obtained from Delaware Bay Observing System (DBOS). Comparisons show good agreement between model results and observations. Strong tidal modulations of surface waves are identified in both model results and measured data. A nearshore community model system NearCoM couples SWAN and SHORECIRC models based on the Master Program implementation. The system is used in a series of numerical experiments that are carried out in an idealized, alongshore uniform domain, which includes a planar beach, land and shelf with constant slopes, in order to explore the response of storm-induced inundation, storm surges as well as waves to wave forcing and to different cyclone parameters through atmospheric forcing. Four sets of experiments are conducted to investigate four factors, radium of maximum wind, track of tropical cyclone, maximum wind speed as well as translation speed, respectively, in affecting storm surges and coastal inundation. Each experiment is conducted twice (with and without wave effect in the model system) to examine the wave setup effect. Coastal inundation, storm surge and wave are sensitive to all four factors. Wave setup always results in larger storm surge and inundation area.

Integration of Different Wave Forcing Formulations with Nearshore Circulation Models

Integration of Different Wave Forcing Formulations with Nearshore Circulation Models PDF Author: Abhishek Sharma
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Wave-induced circulation in general coastal environments is simulated by coupling two widely-used finite-element models, namely, a refraction-diffraction-reflection model based on the elliptic mild-slope equation, and a two-dimensional (depth-averaged) shelf-scale circulation model. Such models yield wave-induced current-fields and set-up/down. This involves exploration of some numerical and practical issues, for example, the selection of appropriate boundary condition and grid resolution, numerical errors owing to higher-order derivatives, etc. Computations of the wave forcing from the elliptic wave model, and the wave-induced quantities from the circulation model, are validated with theoretical and published results. The coupled system is then used to simulate the wave-induced circulation in the domains where structures (e.g. breakwater, jetty, etc.) and bathymetric features (e.g. shoal, etc.) are present. In practice, usually an approximate form of the wave-induced forcing is used. This has certain limitations in some application, which have been poorly studied so far. Therefore, here we consider two alternative approaches. The performance of these wave forcing formulations is examined in the regions where the effects of wave reflection, diffraction and focusing are significant. It is observed that the "generalized approach" provides satisfactory results in most situations, provided a grid resolution of L/10 or more is achievable for the wave model domain. The widely-used simplified approach may produce a chaotic pattern of set-up/down and current field in the regions where the wave field is not purely progressive. The third approach ignores the effect of wave diffraction and reflection, and primarily simulates the effect of energy dissipation. Differences up to 25 percent are observed between the modeled current fields obtained with the generalized and the simplified approach. The results suggest that the generalized approach can be used with little practical difficulty and greater reliability.

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.

Numerical Modelling of Wave Energy Converters

Numerical Modelling of Wave Energy Converters PDF Author: Matt Folley
Publisher: Academic Press
ISBN: 0128032111
Category : Technology & Engineering
Languages : en
Pages : 308

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Book Description
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

Next Generation Earth System Prediction

Next Generation Earth System Prediction PDF Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309388805
Category : Science
Languages : en
Pages : 351

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Book Description
As the nation's economic activities, security concerns, and stewardship of natural resources become increasingly complex and globally interrelated, they become ever more sensitive to adverse impacts from weather, climate, and other natural phenomena. For several decades, forecasts with lead times of a few days for weather and other environmental phenomena have yielded valuable information to improve decision-making across all sectors of society. Developing the capability to forecast environmental conditions and disruptive events several weeks and months in advance could dramatically increase the value and benefit of environmental predictions, saving lives, protecting property, increasing economic vitality, protecting the environment, and informing policy choices. Over the past decade, the ability to forecast weather and climate conditions on subseasonal to seasonal (S2S) timescales, i.e., two to fifty-two weeks in advance, has improved substantially. Although significant progress has been made, much work remains to make S2S predictions skillful enough, as well as optimally tailored and communicated, to enable widespread use. Next Generation Earth System Predictions presents a ten-year U.S. research agenda that increases the nation's S2S research and modeling capability, advances S2S forecasting, and aids in decision making at medium and extended lead times.

Coastal Engineering

Coastal Engineering PDF Author: Dominic Reeve
Publisher: CRC Press
ISBN: 135116550X
Category : Technology & Engineering
Languages : en
Pages : 675

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Book Description
Effective coastal engineering is expensive, but it is not as costly as neglect or ineffective intervention. Good practice needs to be based on sound principles, but theoretical work and modelling also need to be well grounded in practice, which is continuously evolving. Conceptual and detailed design has been advanced by new industry publications since the publication of the second edition. This third edition provides a number of updates: the sections on wave overtopping have been updated to reflect changes brought in with the recently issued EurOtop II manual; a detailed worked example is given of the calculation of extreme wave conditions for design; additional examples have been included on the reliability of structures and probabilistic design; the method for tidal analysis and calculation of amplitudes and phases of harmonic constituents from water level time series has been introduced in a new appendix together with a worked example of harmonic analysis; and a real-life example is included of a design adapting to climate change. This book is especially useful as an information source for undergraduates and engineering MSc students specializing in coastal engineering and management. Readers require a good grounding in basic fluid mechanics or engineering hydraulics, and some familiarity with elementary statistical concepts.

Random Seas and Design of Maritime Structures

Random Seas and Design of Maritime Structures PDF Author: Yoshimi Goda
Publisher: World Scientific
ISBN: 9789810232566
Category : Technology & Engineering
Languages : en
Pages : 478

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Book Description
Random waves are the most important constituent of the sea environment. They make the design of maritime structures quite different from that of structures on land. In this book, the concept of randomness in waves for the design of breakwaters, seawalls, and harbor structures is fully explored for easy comprehension by practicing engineers. Theoretical aspects are also discussed in detail for further studies by graduate students and researchers. Several additions have been made to this second edition, including a new chapter on extreme wave statistics.

Ocean Wave Energy

Ocean Wave Energy PDF Author: Joao Cruz
Publisher: Springer Science & Business Media
ISBN: 3540748954
Category : Technology & Engineering
Languages : en
Pages : 435

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Book Description
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.