Download or read book Discrete Particle Model for Bedload Sediment Transport in the Surf Zone written by Joseph Calantoni and published by . This book was released on 2002 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: critical angle, energetics, slopes, beach, sand.
Download or read book Discrete Particle Model for Bedload Sediment Transport in the Surf Zone written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Predicting the evolution of nearshore bathymetry from the highest uprush of the swash offshore to the location of wave breaking is a difficult problem of significant importance, with economic, legal, engineering, scientific, and military implications for coastal environments. Despite the apparent accessibility of the phenomena of interest, namely, the motion of sand under the forcing of waves and currents, the predictive capability of existing models for nearshore evolution is poor. A detailed study of the forces exerted on individual sand grains is undertaken in an effort to elucidate sediment transport mechanisms in the surf zone. New results indicate that fluid acceleration is a particularly important feature of surf zone transport; likewise, the processes of particle size segregation and the role of particle shape are newly explored. The study methodology employs computer simulations that describe the collective and individual motions of discrete particles immersed in a Newtonian fluid having essentially arbitrary density and viscosity. In this study all particle properties are those of quartz sand, and the fluid properties correspond to saltwater at 20 & deg;C. Such discrete-particle models, having a basis in molecular dynamics studies, have a broad range of applications in addition to the sedimentological one of interest here; for example, similar methodologies have been applied to traffic flow, schooling fish, crowd control, and other problems in which the particulate nature of the phenomenon is of critical importance.
Download or read book Mechanics of Coastal Sediment Transport written by J?rgen Freds?e and published by World Scientific. This book was released on 1992 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book treats the subject of sediment transport in the marine environment, covering transport of non-cohesive sediment by waves and current in- and outside the surf zone. It can be read independently, but a background in hydraulics and basic wave mechanics is required. It is intended for M.Sc. and Ph.D. students. The primary aim of the book is to describe the physical processes of sediment transport and how to represent them in mathematical models. It does not present a large number of different formulae for the sediment transport rates under various conditions. The book can be divided in two main parts; in the first, the relevant hydrodynamic theory is described; in the second, sediment transport and morphological development are treated. The hydrodynamic 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 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.
Download or read book Coastal Bottom Boundary Layers and Sediment Transport written by Peter Nielsen and published by World Scientific. This book was released on 1992 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is intended as a useful handbook for professionals and researchers in the areas of Physical Oceanography, Marine Geology, Coastal Geomorphology and Coastal Engineering and as a text for graduate students in these fields. With its emphasis on boundary layer flow and basic sediment transport modelling, it is meant to help fill the gap between general hydrodynamic texts and descriptive texts on marine and coastal sedimentary processes. The book commences with a review of coastal bottom boundary layer flows including the boundary layer interaction between waves and steady currents. The concept of eddy viscosity for these flows is discussed in depth because of its relation to sediment diffusivity. The quasi-steady processes of sediment transport over flat beds are discussed. Small scale coastal bedforms and the corresponding hydraulic roughness are described. The motion of suspended sand particles is studied in detail with emphasis on the possible suspension maintaining mechanisms in coastal flows. Sediment pickup functions are provided for unsteady flows. A new combined convection-diffusion model is provided for suspended sediment distributions. Different methods of sediment transport model building are presented together with some classical models.
Download or read book The Effect of Fluid Acceleration on Sediment Transport in the Surf Zone written by William McKinney Durham and published by . This book was released on 2006 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) The validity of the two predictive models is substantiated by experiments conducted in a laboratory wave flume. Breaking waves are passed over lightweight, plastic beads representive of uncohesive sediment. The surficial and subsurface transport is experimentally measured. Using velocity records from the laboratory waves, the theoretical models are used to make predictions of each type of transport. Both models produce good agreement with experimental observations. Finally, laboratory wave data from Madsen (1974) are scaled to the the size of waves typical of the surf zone. Using parameters characteristic of sand, the two models predict a subsurface transport of the same order as bedload transport for typical wave and sediment parameters. Furthermore, subsurface transport is found to be proportional to the characteristic length scale of the wave squared, while bedload transport is proportional to the length scale to the power of 1.5.
Download or read book The Bed load Function for Sediment Transportation in Open Channel Flows written by Hans Albert Einstein and published by . This book was released on 1950 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Model for On offshore Sediment Transport in the Surfzone written by James Alan Bailard and published by . This book was released on 1982 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: An energetics-based surfzone sediment transport model is evaluated for its ability to predict on-offshore sediment movements using nearshore sediment transport study current meter and beach volume measurements. The magnitude and distribution of pertinent wave velocity moments are also evaluated from the same data set. The latter were found to be linear functions of the significant wave height. Results of the study showed that the current meter data were of insufficient length to evaluate the sediment transport model's validity. A simplified version of the model coupled with estimated wave velocity moment regression equations was found to mimic observed beach volume variations as a function of wave height. (Author).
Download or read book Sediment Transport in Random Waves written by S. S. Liang and published by . This book was released on 1973 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanics of sediment transport under wave action are systematically investigated. Results are then extended to a random wave field. The results apply only to regions well beyond the surf zone where the flow field, though irregular in appearance, is still amenable to mathematical expressions in gross terms. The flow field is artificially divided into two zones: the bed layer, and the internal flow region where viscosity can be neglected. The analysis is then naturally broken down into several stages: (1) The simulation of random sea condition in time and space frames with given wave spectrum; (2) The sediment concentration and transport in the bed layer under random wave; (3) The suspended load concentration and transport in the internal flow region. The total sediment transport is calculated through matching boundary conditions of the two zones and by adding the bed-load and suspended-load movements. Computer programs are developed to facilitate calculations with overwater wind speed and sediment grain size as the major inputs. (Modified author abstract).
Download or read book Smooth Particle Hydrodynamics for Surf Zone Waves written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smoothed Particle Hydrodynamics (SPH) is a meshless numerical method that is being developed for the study of nearshore waves and Navy needs. The Lagrangian nature of SPH allows the modeling of wave breaking, splash-up, and the subsequent fluid turbulence, which in large part is comprised of coherent turbulent structures. The objectives of this project are to improve the SPH model for use in unraveling the physics of breaking waves, including the description of the wave-induced turbulence and sediment transport within the surf zone. The approach is based on improving various aspects of the SPH code; applying the code to more validation tests; and to examine in some detail new aspects of the model by applying it to different situations. The development of a hybrid model, that is, coupling the SPH particle model to a conventional finite difference model (a Boussinesq model, FUNWAVE) is being explored.
Download or read book Coal Ash Basin Effects particulates Metals Acidic PH Upon Aquatic Biota written by and published by . This book was released on 1984 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanics of Sediment Transport written by A. Mueller and published by CRC Press. This book was released on 2020-08-26 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the studies on sediment transport in suspension and sediment transport in steep channels. It discusses the degradation and particle sorting processes.
Download or read book An Approach to the Sediment Transport Problem from General Physics written by Ralph Alger Bagnold and published by . This book was released on 1966 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: From considerations of energy balance and of mechanical equilibrium, a mathematical expression is derived relating the rates of sediment transport as bedload and as suspended load to the expenditure of power by a statistically steady flow of water.
Download or read book Wave Boundary Layer Hydrodynamics and Cross shore Sediment Transport in the Surf Zone written by David González Rodríguez (Ph. D.) and published by . This book was released on 2009 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) The hydro-dynamical predictions and the corresponding bedload sediment transport predictions by this analytical model agree with the available sheet flow experimental data, with the bed roughness being consistently characterized by the total mobile-bed roughness. Unlike the OWT case, where waves do not propagate, waves in a flume or in the sea are propagating. We outline the extension of the analytical model to propagating waves and quantify the hydrodynamical and bedload sediment transport differences between propagating and non-propagating waves. These differences are significant and need to be accounted for when interpreting OWT results.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Waves Currents and Sediment Transport in the Surf Zone Along Long Straight Beaches written by Yoshimitsu Tajima and published by . This book was released on 2004 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Introducing the predicted near-shore hydrodynamic characteristics, we extend the conceptual bedload and associated suspended load sediment transport models (Mad- sen, 2001) to the surf zone. The extended sediment transport model accounts for breaking wave effects such as an increase of turbulence due to broken waves and change of the momentum force balances due to breaking waves and surface rollers. The model predicted the peaks of longshore sediment transport observed near the shore line and the wave breaking point for plunging breakers.
Download or read book Modeling and Practice of Erosion and Sediment Transport under Change written by Mohamed Meddi and published by MDPI. This book was released on 2019-09-17 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate and anthropogenic changes impact the conditions of erosion and sediment transport in rivers. Rainfall variability and, in many places, the increase of rainfall intensity have a direct impact on rainfall erosivity. Increasing changes in demography have led to the acceleration of land cover changes in natural areas, as well as in cultivated areas, and, sometimes, in degraded areas and desertified landscapes. These anthropogenized landscapes are more sensitive to erosion. On the other hand, the increase in the number of dams in watersheds traps a great portion of sediment fluxes, which do not reach the sea in the same amount, nor at the same quality, with consequences on coastal geomorphodynamics. This book is dedicated to studies on sediment fluxes from continental areas to coastal areas, as well as observation, modeling, and impact analysis at different scales from watershed slopes to the outputs of large river basins. This book is concentrated on a number of keywords: “erosion” and “sediment transport”, “model” and “practice”, and “change”. The keywords are briefly discussed with respect to the relevant literature. The contributions in this book address observations and models based on laboratory and field data, allowing researchers to make use of such resources in practice under changing conditions.
Download or read book Waves on Beaches and Resulting Sediment Transport written by Richard E. Meyer and published by . This book was released on 1972 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
