Non-cohesive Sediment Transport Research Articles

Sediment transport in rigid bed conveyances

This paper is based on extensive new experimental investigations of bedload transport of noncohesive sediments in fixed bed conveyances with no deposition. Using these new as well as previously available data an attempt has been made to resolve some differences in previously published work and to advance the understanding of the processes involved. The paper summarises the proposed methodologies and provides a thorough comparison with the alternative ones that exist in loose and fixed boundary conveyances.

Numerical modelling of suspended sediment fluxes in estuarine waters

A two-dimensional finite difference numerical model, capable of predicting depth-averaged tidal flow fields in coastal and estuarine waters, has been extended to include tide-induced non-cohesive sediment transport processes. The partial differential equations governing the conservation of mass, momentum and suspended sediment in an incompressible turbulent flow are included in a depth-integrated form in the model. For the representation of the processes of erosion and deposition of sediment from the bed an empirically based source-sink term was refined, based on the results of three mobile bed flume studies. The model has been tested by simulating tidal flows and suspended sediment fluxes in two estuaries, with particular application to the Humber estuary in the U.K. The model was calibrated and found to produce an encouraging degree of agreement between the numerical predictions and corresponding field measurements for this estuary. Furthermore, the predicted gross deposition and erosion features of the estuary were found to be in close agreement with interpretations from Eulerian tidal residual predictions.

Experiments on sediment transport in shallow flows in high gradient channels

Abstract The main objective of this paper is to present the results of an experimental study relating to the transport of sediment under certain conditions not typical of river sedimentation studies. The area of sediment transport lacks information on the transport down high gradient channels that are typical of streets, construction sites and agricultural land, in addition to mountain torrrents. The study of transport of non-cohesive sediment in high gradient channels includes determination of the transport capacity of shallow flows in high gradient channels with simulated bed roughness and various grain sizes. Regression analysis was performed to relate the dependent and independent variables in functional relationships and revealed good correlation.

Sediment-Contaminant Transport Model

The unsteady, two-dimensional model, FETRA, was developed to simulate both sediment and contaminant transport in rivers and esturies. The model consists of three submodels which, when used jointly accurately depict the interaction and migration of sediment, dissolved contaminants, and particulate contaminants. FETRA solves the migration (transport, deposition and resuspension) of cohesive and noncohesive sediments and particulate contaminants of three sediment-size fractions. FETRA was applied to the James River estuary to simulate the migration of river sediments and the pesticide, Kepone. Computed results produced by the model are very similar to field-measured data, meaning that FETRA is reasonably accurate.

Attenuation of sound in suspensions and emulsions: Theory and experiments : Allegra, J.R., Hawley, S.A. Vol 51 No 5 Part 2 (May 1972) pp 1545–1564

For over two decades, coastal marine scientists studying boundary layer sediment transport processes have been using, and developing, the application of sound for high temporal–spatial resolution measurements of suspended particle size and concentration profiles. To extract the suspended sediment parameters from the acoustic data requires an understanding of the interaction of sound with a suspension of sediments and an inversion methodology. This understanding is distributed around journals in a number of scientific fields and there is no single article that succinctly draws together the different components. In the present work the aim is to provide an overview on the acoustic approach to measuring suspended sediment parameters and assess its application in the study of non-cohesive inorganic suspended sediment transport processes.

Some Fundamental Particularities On PartlyCohesive Sediment Transport In A Circular TestFlume

The complex sediment transport phenomena in narrow sewer pipes are studied in a physical scale model. Since sewer deposits contain not only sand but also cohesive mud particles, the partly cohesive material will act differently than the traditional non-cohesive sediments. In recent literature, only a few studies on partly cohesive sediments have been presented. Therefore, a fundamental investigation on the erosional behaviour is set up. The major aim of the experiments is to point out essential similarities and differences in the particular behaviour of these sediments in a circular cross-section, in relation to the wellestablished non-cohesive sediment transport approach.

Numerical Modelling Of Three-dimensional Non-Cohesive Sediment Transport In Java Sea

In the framework of an integrated research project on prediction of beach and sea floor topography changes in Java Sea, the development of a three-dimensional non-cohesive sediment transport model to predict suspended sediment fluxes has been carried out by solving the advection-diffusion equation. The velocity fields were calculated by using a three-dimensional hydrodynamic model of tideand wind-driven circulation incorporating the influence of wind waves generated at the sea surface. The third generation wave model WAM (WAMDI ) was used to calculate the wave parameters and the wave dependence of the drag coefficient. To represent the monsoon wind fields which play an important role in generating the waves and water circulation in the region, ECMWF's one-year hindcasted data of six hourly-wind fields at 10 m above the sea surface were used in the simulation. The simulation results show that both for the typical westand east-monsoon the largest values of the suspended sediment concentration can be observed around central part of the Java Sea, where the velocities are largest. One-year computation of the bed level changes in the region produces erosion and deposition in the range 0 to 1.5 cm. Due to the most of the sea floor of the Java Sea being covered by mud (Emery et a//), the model will be extended to predict cohesive sediment transport. These kinds of studies are currently in progress as an extension of this research program. Transactions on the Built Environment vol 40 © 1999 WIT Press, www.witpress.com, ISSN 1743-3509