Download or read book A Particle Tracking Model for Sediment Transport in the Nearshore Zone written by D. M. L. Johnson and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Particle Tracking Model of Sediment Transport written by A. Kelsey and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Particle tracking model of sediment transport written by A. Kelsey and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Sediment Transport in the Nearshore Coastal Zone written by Allison M. Penko and published by . This book was released on 2004 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Particle Tracking Model PTM II Overview of Features and Capabilities written by and published by . This book was released on 2005 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Dredging Operations and Engineering Research (DOER) Technical Note (TN) is the second in a series. It describes the features and capabilities of a new Particle Tracking Model (PTM) for analysis of sediment transport and sediment pathways in coastal waters, estuaries, rivers, and waterways. This note is applicable to Version 1.0 of PTM. The PTM graphical user interface is described in the first TN (Demirbilek et al. 2005a) in this series. A tutorial with examples is described in the third TN (Demirbilek et al. 2005b). PTM has been designed to meet the needs of two U.S. Army Corps of Engineers (USACE) research programs, the Coastal Inlets Research Program (CIRP) and the DOER Program. Examples are presented that illustrate key features of the PTM s application in coastal and estuarine environments. Accurate prediction of the fate of sediments and other waterborne particulates is a key element in coastal engineering and dredging operations. The PTM simulates sediment movement in a flow field, including erosion, transport, settling, and deposition. In addition to predicting sediment transport pathways and sediment fate, the model produces maps of sediment transport processes, such as sediment mobility, which can be useful in understanding sediment behavior. The reader is referred to MacDonald and Davies (2005) for a comprehensive description of the theoretical formulation and numerical implementation aspects of the PTM.

Download or read book Stochastic Particle Tracking Modeling for Sediment Transport in Extreme Flow Environments written by 林彥廷 and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coastal and Shelf Sediment Transport written by Peter S. Balson and published by Geological Society of London. This book was released on 2007 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a timely review of a representative selection of the different approaches undertaken for coastal and shelf investigations, operating at a variety of temporal and spatial scales, within different regions of the UK/European continental shelf, and elsewhere.

Download or read book Particle Tracking Sediment Transport Model for the Buffalo River written by Pradeep Nagaraja and published by . This book was released on 2008 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle tracking model (PTM) is developed to simulate sediment movement in a river. It includes the same processes as traditional Eulerian (control volume) based models, but adds the capability to follow the pathways of individual particles, which is useful for making remediation decisions that might include, for example, environmental dredging. The PTM tracks the movement of particles based on velocities and dispersion fields generated from a hydrodynamic model, which is a curvilinear, orthogonal grid-based model that can be conveniently used to follow the system boundaries. The movement of a particle is computed using a random walk algorithm. The PTM can function either as a stand-alone model or can be coupled to a hydrodynamic based model such as the Estuarine, Coastal and Ocean Model (ECOM), as was done in this study. The advantage of using the PTM as a stand-alone model is that it could be used independently for specific cases and hence, would save on computation time. However, it can be coupled with a hydrodynamic model in cases where the velocity and dispersion fields are sensitive to particle movements or bed elevation changes. The PTM includes boundary interactions such as reflection, deposition and resuspension, and can be compared with more traditional sediment transport models by correlating the number of particles in a grid cell to a concentration. The PTM has been used in an application to track the sediments in the Buffalo River, and provides a useful tool for current discussions of possible sediment remediation options.

Download or read book Stochastic Particle Tracking Modeling for Sediment Transport in Open Channel Flows written by Jungsun Oh and published by . This book was released on 2011 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sediment transport in flow has a practical impact on environmental and economic aspects of human society, for instance, water quality, hydraulic structures and land resources. A systematic understanding of the sediment transport processes is of critical significance to establish proper water resources and sediment management plans. Both random properties of flows and varying properties of sediment particles can induce stochastic nature of sediment particle movement in the flows. Thus, stochastic approaches or analyses are beneficial to analyzing the variability associated with the movement of sediment particles. In this context, the focus of this study is to model various features of sediment transport in open channel flow with stochastic approaches.^The scope of the study includes the following main issues: the movement of sediment particles in turbulent open channel flows in the occurrences of extreme flows, the deposition and resuspension processes of sediment particles, sediment concentrations and its uncertainty, and various modeling framework of stochastic particle tracking models. Turbulence in a flow is a primary source of stochastic property of particle movement in the flow. Furthermore, extreme flows that might occur occasionally in a random manner reinforce the randomness of the movement of sediment particles in the flow. The volatile flow velocity of extreme flows will not only affect the mean trend of particle movement but also intensify the uncertainty of particle movement. Specifically, since extreme flow events randomly occur per se, the random manner of the occurrences generates the stochastic property that affects the movement of sediment particles.^Thus, it is effective to employ stochastic approaches for describing sediment transport processes associated with uncertainty. Herein, both a & lsquo;stochastic diffusion process & rsquo; and a & lsquo;stochastic jump diffusion process & rsquo; are introduced to describe stochastic particle movement in open channel flows. The & lsquo;stochastic jump diffusion process & rsquo; represents the particle movement in response to extreme flow events that randomly occur in a turbulent open channel flow, whereas the & lsquo;stochastic diffusion process & rsquo; characterizes the particle movement in a turbulent open channel flow. As a result, both the stochastic diffusion particle tracking model (SD-PTM) and the stochastic jump diffusion particle tracking model (SJD-PTM) can present particle trajectories, and roughly estimated instantaneous velocities.^The ensemble statistics of the particle trajectories and velocities radically contain information on the stochastic characteristics of sediment particle movement. The SD-PTM and SJD-PTM to estimate particle trajectory and velocity is verified with data of Sumer and Oguz (1978), Muste and Patel (1997), Cuthberson and Ervine (2007) and Muste et al. (2009). The sediment concentration and sediment flux are highly-sought, practical variables in that the existence and amount of suspended sediments in surface waters have a direct influence on water quality and its suitability for drinking and industrial purposes. Especially, the estimation of sediment concentrations demonstrates the transporting process of suspended sediment through its spatial and temporal distributions. The sediment concentrations play a significant role as a pragmatic indicator in the decision making process.^Thus, the previous-stated particle-based stochastic approach for sediment transport is enhanced to predict the suspended sediment concentration, and to quantify the uncertainty of the sediment concentrations. The method also allows for particle entrainment into flows and particle settlement on the bed as main processes in open channel flows. Through multiple realizations of the particle movement with stochastic properties, the SD-PTM shows not only sediment concentrations at a specific location and time but also uncertainty for the estimated sediment concentrations. The proposed method, in this context, is a more straightforward method to evaluate uncertainty due to stochastic properties in the particle movement and a unique way to present the uncertainty of sediment concentrations. The proposed stochastic particle tracking model for sediment concentrations is verified with data of Coleman (1986).^The final goal of this study is to pursue further investigation into two different types of stochastic particle tracking approaches describing sediment particle movement associated with randomness. The different types of approaches are classified into the & lsquo;univariate & rsquo; and the & lsquo;multivariate & rsquo; stochastic particle tracking models according to the selection of key stochastic variables that describe the randomness of natural phenomena. In the & lsquo;univariate & rsquo; stochastic particle tracking model, one state vector (e.g., particle position) is regarded as a targeted variable. The above proposed models can be thought of as the & lsquo;univariate & rsquo; stochastic particle tracking model. In the & lsquo;multivariate & rsquo; stochastic particle tracking model, the sediment particle velocity and position are joint Markovian state variables, since the flow velocity evolves in time according to a generalized stochastic differential equation.^Model comparisons are performed and both models are verified with data of Sumer and Oguz (1978).

Download or read book Particle Tracking Model PTM in the SMS written by Zeki Demirbilek and published by . This book was released on 2005 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Hydrodynamic and Sediment Transport Model for Nearshore Coastal Regions written by Xiao Li and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Space time Sediment Relationships in the Nearshore Zone written by Jay E. Leonard and published by . This book was released on 1977 with total page 1132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Multi dimensional Two phase Flow Modeling Framework for Sediment Transport Applications written by Zhen Cheng and published by . This book was released on 2016 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studying coastal processes is essential for the sustainability of human habitat and vibrancy of coastal economy. Coastal morphological evolution is caused by a wide range of coupled cross-shore and alongshore sediment transport processes associated with short waves, infra-gravity waves, and wave-induced currents. One of the key challenges was that the major transport occurs within bottom boundary layers and it is dictated by turbulence-sediment interactions and inter-granular interactions. Therefore, this study focuses on numerical investigations of sediment transport in the bottom wave boundary layers on continental shelves and nearshore zones, with emphasis on both fine sediment (mud) and sand transports. On the continental shelves, the sea floor is often covered with fine sediments (with settling velocity no more than a few mm/s). Wave-induced resuspension has been identified as one of the major mechanisms in the offshore delivery for fine sediments. A series of turbulence-resolving simulations were carried out to study the role of sediment resuspension/deposition on the bottom sediment transport. Specifically, we focus on how the critical shear stress of erosion and the settling velocity can determine the transport modes. At a given wave intensity associated with more energetic muddy shelves, three transport modes, namely the well-mixed transport (mode I), two-layer like transport with the formation of lutocline (mode II) and laminarized transport (mode III), are obtained by varying the critical shear stress of erosion or the settling velocity. A 2D parametric map is proposed to characterize the transition between transport modes as a function of the critical shear stress and the settling velocity at a fixed wave intensity. In addition, the uncertainties due to hindered settling and particle inertia effects on the transport modes were further studied. Simulation results confirmed that the effect of particle inertia is negligible for fine sediment in typical wave condition on continental shelves. On the other hand, the hindered settling with low gelling concentration can play a key role in sustaining a large amount of suspended sediments and results in the laminarized transport (mode III). Low gelling concentrations can also trigger the occurrence of gelling ignition, a state in which the erosion rate always exceeds the deposition rate. A sufficient condition for the occurrence of gelling ignition is hypothesized for a range of wave intensities as a function of sediment/floc properties and erodibility parameters. In the more energetic nearshore zones, the sea floor is often covered with sand (with settling velocity exceeds 1 cm/s). Based on the open-source CFD toolbox OpenFOAM, a multi-dimensional Eulerian two-phase modeling framework is developed for sediment transport applications. With closures of particle stresses and fluid-particle interactions, the model is able to resolve full sediment transport profiles without conventional bedload/suspended load assumptions. The turbulence-averaged model is based on a modified k-epsilon closure for the carrier flow turbulence and it was used to study momentary bed failure under sheet flow conditions. Model results revealed that the momentary bed failure and the resulting large transport rate were associated with a large erosion depth, which was triggered by the combination of large bed shear stresses and large horizontal pressure gradients. In order to better resolve turbulence-sediment interactions, the modeling framework was also extended with a 3D turbulence-resolving capability, where most of the turbulence-sediment interactions are directly resolved. The model is validated against a steady sheet flow experiment for coarse light particles. It is found that the drag-induced turbulence damping effect was more significant than the well-known density stratification for the flow condition and grain properties considered. Meanwhile, the turbulence-resolving model is able to reproduce bed intermittency, which was driven by turbulent ejection and sweep motions, similar to the laboratory observation. Finally, simulations for fine sand transport in oscillatory sheet flow demonstrate that the turbulence-resolving model is able to capture the enhanced transport layer thickness for fine sand, which may be related to the burst events near flow reversal. Several future research directions, including further improvements of the present modeling framework and science issues that may be significantly benefited from the present turbulence-resolving sediment transport framework, are recommended.

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 Engineering 2004 Proceedings Of The 29th International Conference In 4 Vols written by Jane Mckee Smith and published by World Scientific. This book was released on 2005-04-08 with total page 4836 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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:

Download or read book Modeling Sediment Transport in a Nearshore Environment Using a Two dimensional Model written by Conor Davitt and published by . This book was released on 2003 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: