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,...

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...

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...

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...

The Structure of Intermittent Sand Suspension Events Under Mild Wave Conditions
Nearshore sedimentation processes are being actively investigated through a series of research projects at the University of Miami. Quantitative measurements of waves, currents, and suspended...

Sediment?Hyperconcentration Flow and Its Similarity Laws
The sediment- hyperconcentration flow are studied theoretically and experimentally, and the formulas for the Bingham shear stress, rigidity coefficient, fall velocity and transport capacity...

Flow Modeling in the Toutle River, Washington
In support of flow, suspended load, bed load, and bedform transport measurements, a quasi-three-dimensional river flow model was adapted to a reach extending from 260m upstream to 30m...

Mechanics of Mud Flows in Curved Channels with Uneven Beds
Most natural debris flows move through paths that are curved and that have significant bed topography. Owing to the dependence of the mechanics of wet debris containing substantial amounts...

Bank Failure and Erosion on the Illinois Waterway
In 1988, bank failure and erosion on the Illinois Waterway were evaluated. Banks were inspected from the air and from a motor vessel; thirty-one sites were examined in detail. Severe erosion...

Boundary Conditions of Tidal Model at River Mouth
A small grid is required to schematize irregular shape of shoreline in the vicinity of river mouth which limits the modeling area to be small. Tidal records along the boundary show no...

Sorting of Mixed Sand on a Two-Dimensional Beach
A numerical method is developed to predict temporal variations of the sea bed topography and the bed-material composition. The predicted results are compared with the measurements in a...

Interfacial Instability in Highly Stratified Flows
The stability of highly stratified shear flows is dependent on several parameters including the thickness of the interfacial transition layer. Experimental results show that the thickness...

Cellular Automaton Simulation of Viscous Free Surface Fluid Dynamics
It has been demonstrated elsewhere that the simple interaction of a two dimensional field of discrete particles traveling on a regular lattice yields large scale behavior closely approximating...

Verification of Local Modes in a Two-Dimensional Tidal Model
Based on a generalized model equation, a two-dimensional hybrid finite element model has been developed to study tidal waves of incompressible, homogeneous fluid in rotational flows. In...

Risk-Cost Principles for Dam Safety Analysis
The purpose of this paper is to present the principles and issues of risk-cost analysis as they have evolved in the evaluation of dam safety improvements. The paper also reviews some results...

Design of Expansions for Sub-Critical Open Channel Flow
Expansions for open channel flow at sub-critical velocity are required whenever it is necessary to reduce the velocity of flow from a structure which discharges into an erodible channel....

Lower Santa Ana River Hydraulic Design for Levee Overtopping
The purpose of overtopping or freeboard design is to minimize damages and catastrophic failure from floodwaters overtopping levees. This case study is presented to show the approach taken...

Overfall Stress and Pressure Distributions
The magnitude and distribution of hydraulic shear stress and pressure on the boundary of a straight drop overfall are presented for multiple overfall heights and flow rates. Hydraulic...

 

 

 

 

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