The State of Art of Physical Modelling of Sediment Transport
The paper attempts formula some ideas about the state of the art in the field of physical modelling of sediment transport processes. Up to now the physics of sediment transport are not...

Advances in Computational Mobile-Bed Hydraulics
A new conceptual approach to one-dimensional mobile-bed simulation is briefly described, along with two demonstrative examples. The approach is based on fully coupled solution of the unsteady...

Potential Flow Over a Wavy Bed: A Persistent Error
The standard small-amplitude theory of potential flow over a wavy bed is briefly discussed, together with the three special values of the Froude Number which define four different flow...

Modeling of Contaminant Transport in Rivers with Emphasis on the Interaction with Movable Boundaries
The transport of dissolved and absorbed pollutants is simulated by a one-dimensional convection-diffusion model which particularly accounts for the exchange processes at the river bed...

Friction Slope Computation for Mathematical Models
The behavior of the energy flow gradient as function of depth and velocity is analyzed for three flow resistance methods. In the paper, the necessary modifications introduced to the methods...

Comparison of n Values in Natural and Dredged Channels
Manning's n values were determined for three stream channels in two complex watersheds in North Mississippi. The study covered a wide range of channel conditions and flow...

Self-Accelerated Turbidity Current Prediction Based Upon Dynamic Turbulence Models
The structure of a self-accelerated turbidity current appears to be significantly better predicted by a dynamic Reynolds stress turbulence model than by one- and two- equation models....

Modeling Sediment Transport in Rectangular Ducts with a Two-Equation Model of Turbulence
The paper deals with the application of a two-equation model of turbulence to the calculation of flows in rectangular ducts. A non-linear relationship is used to link the Reynolds stresses...

Mathematical Models for Turbulent Shear Stress in Sediment-Laden Flows
Turbulent shear stress in sediment-laden flows has been examined by several investigators including H.A. Einstein and N. Chien A. Zagustin and J.C. Willis. Three derivations resulted in...

Weighted Finite Difference Method for Diffusive Transport
The purpose of the paper is to present an application of a new method to the two-dimensional, transient advective-diffusive transport in both turbulent flow of viscous fluid and seepage...

Reliability of Bank Protection Works Subject to Erosion
Sediment movement and changes of bed levels in natural rivers are non-stationary processes. The design of protection works for structures against erosion should account for the time dependency...

Wave?Current Interaction and Sediment Transport
The paper reports on a study into whether a close relationship between the mixing (diffusion) coefficient for the sediment, ?s, and the mixing (diffusion)...

Transport of Grain-Water Mixture by Waves
The numerical modelling of the morphological changes of coastal regions is hampered by the multiplicity of empirical sediment transport formulae. The paper discusses the modes of transport...

Towards a Distinct Treatment of Incipient Motion for Bed Forms of Low Regime
The principle methods for estimating the incipient particle motion on developed bed forms in the lower regime are compared with each other. Usually only a part of the total wall shear...

The Beginning of Sediment Transport as a Probability-Problem
Sediment transport only takes place when the action of flow (shear stress, velocity) exceeds a critical value. The limit between rest and movement can be given as critical flow velocity,...

A Continuum Mechanics Approach to Loose-Bed Motion
A mathematical model is presented for simulation of loose-bed motion. The physical system is separated into two regions, a bottom region and an upper region. The bottom region is representative...

Critical Shear Stress of Armour Coat
The problem of the determination of the critical shear stress of the armour coat is important in sediment transport, river degradation and aggradation and flow discharge regulation. The...

Integral Length Scale in Sediment-Suspending Flow
The Clauser integral length scale is an adequate scaling parameter for velocity defect profiles in clearwater and sediment-suspending flows in open channels. Velocity defect profiles plotted...

Near Bed Sediment Concentration as Influenced by Turbulence
Suspended sediment concentration profiles are developed based on the conservation of mass and conservation of momentum equations of sediment laden flows. The resulting concentration profile...

Modeling Erosion and Deposition Due to Suction and Jet Flows
PHOENICS, a commercial 3-D computational fluid dynamics software package, was modified for simulating seabed erosion and deposition. Time varying sediment fluidization, transport and deposition...

 

 

 

 

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