Derivation of a Stability Principle from the Shields Criterion
The widely used specific energy equation, which defines the subcritical and supercritical states of the open channel flow, is a direct result of the integration of the Froude number corresponding...
Modelling Changes in Coastal Morphology
A description is given of a newly-developed coastal sediment transport model. Features of the model are the inclusion of cross-shore transport and non-potential suspended load, the latter...
Modelling of Sand Bars in Coastal Environments
A mathematical model describes the formation of sand bars by progressive wind-generated waves. The model decomposes into several constituents linked together in a two step morphological...
Engineering Models for Coastal Sediment Transport
During the last ten years Danish Hydraulic Institute (DHI) has together with the Institute of Hydrodynamics and Hydraulic Engineering (ISVA) of the Technical University of Denmark been...
A New Turbulence Model: The k-?-S Model
A new turbulence model, the k-?-S( turbulent kinetic energy-dissipation-Stochastic theory) model, is presented. Instead of the Boussinesq eddy viscosity concept in the k-? -E( turbulent...
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...
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...
Using Sediment-Threshold Theories in Waves and Currents
Fundamentally different threshold-of-motion theories were applied to sand transport in two different coastal environments. Several recommendations for threshold application were reached....
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...
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...
Instability of Bed-Surface Composition Due to Sorting Process in a Stream Composed of Sand and Gravel
Wavy patterns of sorting are often observed in a stream composed of sand and gravel, and they are regarded as instability of bed-surface composition due to selective bed-load transport...
Sediment Transport Model for Muddy Tidal Rivers
This paper describes the development and application of a one-dimensional mathematical model capable of simulating the changes to the cross-sections of a muddy tidal river over a time...
A Finite Element Application of Sand Terrace Formation Process
In this paper, the formation process of a sand terrace in front of river mouth is simulated numerically by means of the finite element method. The two-step explicit scheme is applied as...
Mid-Scale Laboratory Tests on a Two-Dimensional Movable-Bed Sand Model
A two-dimensional physical model was used to simulate wave-induced scour in front of a concrete dike sloped at 1:4. The tests were conducted at the U.S. Army Engineers Waterways Experiment...
Lessons from Ten Years Experience in 2D Sediment Modeling
The purpose of this paper is to share some of the lessons learned from the experience of the Hydraulics Lab Estuaries Division (WESHE) in applying two-dimensional (2D) numerical models...
Method to Predict Cropland Ephemeral Gully Erosion
The U.S. Soil Conservation Service (SCS) in cooperation with the Agricultural Research Service (ARS) has developed a microcomputer program to provide estimates of the average annual material...
An Overview of Computer Stream Sedimentation Models
This paper discuss some of the author's experience in computer modeling of stream sedimentation problems. Comparisons of twelve selected models developed and implemented in...
Sediment Transport Modelling from Grain Size Data
Grain-size analysis can be useful in determining some of the hydrodynamic aspects of the evolution of a natural sand body. The suite statistics approach minimizes single-sample anomalies...
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