scholarly journals A NUMERICAL MODEL FOR SEDIMENT TRANSPORT

1978 ◽  
Vol 1 (16) ◽  
pp. 103
Author(s):  
J.P. Lepetit ◽  
A. Hauguel
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Time Scale ◽  
Local Scour ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Propagation Equation ◽  
Coastal Structure ◽  
Two Dimensional Model ◽  
The Impact

We introduce here a numerical two dimensional model for sediment transport which permits to compute the impact of a coastal structure on the bottom evolution. The introduction of current disturbance and some assumptions using difference of time scale between current and bottom evolutions permits to obtain a propagation equation driving the bottom evolution. The model has been calibrated in the case of the local scour around a jetty. At last, it has been applied to the bottom evolution in the vicinity of the new port of Dunkerque.

scholarly journals An experimental and theoretical investigation of particle–wall impacts in a T-junction

2013 ◽  
Vol 727 ◽  
pp. 236-255 ◽  
Author(s):  
D. Vigolo ◽  
I. M. Griffiths ◽  
S. Radl ◽  
H. A. Stone
Keyword(s):  
Flow Direction ◽  
Three Dimensional ◽  
Stokes Number ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Viscous Boundary Layer ◽  
Particle Tracing ◽  
Two Dimensional Model ◽  
Viscous Boundary ◽  
The Impact

AbstractUnderstanding the behaviour of particles entrained in a fluid flow upon changes in flow direction is crucial in problems where particle inertia is important, such as the erosion process in pipe bends. We present results on the impact of particles in a T-shaped channel in the laminar–turbulent transitional regime. The impacting event for a given system is described in terms of the Reynolds number and the particle Stokes number. Experimental results for the impact are compared with the trajectories predicted by theoretical particle-tracing models for a range of configurations to determine the role of the viscous boundary layer in retarding the particles and reducing the rate of collision with the substrate. In particular, a two-dimensional model based on a stagnation-point flow is used together with three-dimensional numerical simulations. We show how the simple two-dimensional model provides a tractable way of understanding the general collision behaviour, while more advanced three-dimensional simulations can be helpful in understanding the details of the flow.

scholarly journals CALCULATION OF THE RATE OF NET ON-OFFSHORE SEDIMENT TRANSPORT ON THE BASIS OF FLUX CONCEPT

1984 ◽  
Vol 1 (19) ◽  
pp. 91 ◽  
Author(s):  
Ichiro Deguchi ◽  
Toru Sawaragi
Keyword(s):  
Sediment Transport ◽  
Water Depth ◽  
Sediment Concentration ◽  
Suspended Load ◽  
Spatial Variations ◽  
Sediment Flux ◽  
Bed Load ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model

Time and spatial variations of sediment concentration of both bed load and suspended load in the process of two-dimensional beach deformation were investigated experimentally. At the same time, the relation between the velocities of water-particle and sediment migration was analyzed theoretically. By using those results,a net rate of on-offshore sediment_ transport in the process of two-dimensional model beach deformation qf was calculated on the basis of sediment flux. It is found that Qf coincides fairly well with .the net rate of on-offshore sediment transport calculated from the change of water depth.

scholarly journals A two-dimensional model of the methane cycle in a sedimentary accretionary wedge

2012 ◽  
Vol 9 (8) ◽  
pp. 3323-3336 ◽  
Author(s):  
D. E. Archer ◽  
B. A. Buffett
Keyword(s):  
Heat Flux ◽  
Passive Margin ◽  
Model Description ◽  
Accretionary Wedge ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Methane Cycle ◽  
Active Margin ◽  
Two Dimensional Model ◽  
The Impact

Abstract. A two-dimensional model of sediment column geophysics and geochemistry has been adapted to the problem of an accretionary wedge formation, patterned after the margin of the Juan de Fuca plate as it subducts under the North American plate. Much of the model description is given in a companion paper about the application of the model to an idealized passive margin setting; here we build on that formulation to simulate the impact of the sediment deformation, as it approaches the subduction zone, on the methane cycle. The active margin configuration of the model shares sensitivities with the passive margin configuration, in that sensitivities to organic carbon deposition and respiration kinetics, and to vertical bubble transport and redissolution in the sediment, are stronger than the sensitivity to ocean temperature. The active margin simulation shows a complex sensitivity of hydrate inventory to plate subduction velocity, with results depending strongly on the geothermal heat flux. In low heat-flux conditions, the model produces a larger inventory of hydrate per meter of coastline in the passive margin than active margin configurations. However, the local hydrate concentrations, as pore volume saturation, are higher in the active setting than in the passive, as generally observed in the field.

Influence of inlet and outlet configuration on the flow in secondary clarifiers

1996 ◽  
Vol 34 (5-6) ◽  
pp. 1-9 ◽  
Author(s):  
Peter Krebs ◽  
Anastasios I. Stamou ◽  
Jaime L. García-Heras ◽  
Wolfgang Rodi
Keyword(s):  
Numerical Model ◽  
Numerical Modelling ◽  
Laboratory Experiment ◽  
Flow Rate ◽  
Systematic Evaluation ◽  
Bottom Current ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model ◽  
End Wall

A numerical model for predicting the flow in clarifiers is presented which accounts for density-affected and turbulent flow as well as for the settling of activated sludge. The reliability of the two-dimensional model is demonstrated through verification by means of a laboratory experiment which was specially designed for this purpose. The numerical model is then applied for an evaluation of inlet and outlet arrangements. The inlet is positioned at the bottom and the inlet aperture is varied. An outlet at the top of the end wall is compared with outlets longitudinally extended at the surface. The alternatives are assessed by analysis of streamline patterns, layer charactersitics and the entrainment into the bottom current, i.e. the increase of its flow rate. The study demonstrates how numerical modelling can be used for systematic evaluation of the effect of geometrical configurations on the flow in secondary clarifiers.

scholarly journals A NUMERICAL MODEL OF THE ST. LAWRENCE RIVER

1972 ◽  
Vol 1 (13) ◽  
pp. 127
Author(s):  
David Prandle
Keyword(s):  
Numerical Model ◽  
Flow Distribution ◽  
Flow Visualisation ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Simple Method ◽  
One Dimensional ◽  
Two Dimensional Model ◽  
The One ◽  
St Lawrence River

A one-dimensional numerical model of a 340 mile section of the St. Lawrence River has been formulated to study tidal propagation. For a more detailed study of the flow distribution in a localised section of the river a two-dimensional model was used. A half mile square grid was used to schematise an area of approximately 20 miles long by 15 miles wide. This two-dimensional model was embodied within the one-dimensional model to permit a free interaction of flow across the boundaries. For the one-dimensional case, a comparison of model and prototype results is included for both elevation and velocity. For the two-dimensional model a comparison of flow distribution was made by using field results obtained from photographing ice movement and from drogue movement. To interpret the results of the two-dimensional model into a simple method of flow visualisation, use was made of animation techniques. A movie film was made that demonstrates both tidal rise and fall and the associated horizontal velocities. Elevation was reproduced by use of varying shades of coloured paper to simulate contours, velocities were represented by simulating drogue movement to produce smoke streaks.

Generative Teams: Going Beyond High Performance

2021 ◽  
Vol 23 (3) ◽  
pp. 32-45
Author(s):  
Fernando Caballero
Keyword(s):  
High Performance ◽  
Individual Performance ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model ◽  
State Of Mind ◽  
The Impact ◽  
Systemic View

Al cambiar nuestra atención de un enfoque tradicional centrado en el desempeño individual al de reconocer y apreciar la entidad única del equipo, el ‘nosotros’, aumentamos nuestra capacidad para descubrir y aprovechar su inherente inteligencia, fortalezas y todo su potencial generativo. Para lograr este cambio, el presente artículo propone utilizar como agente catalizador la integración de una mirada sistémica del equipo con un estado mental generativo y el seguimiento continuo del impacto de esta integración por medio de un modelo bidimensional que desarrolle su productividad y positividad. By shifting our attention from a traditional focus on individual performance to recognising and appreciating the unique entity of the team – the ‘we’ – we increase our ability to discover and harness its inherent intelligence, strengths and all of its generative potential. In order to achieve this shift, this article proposes using as a catalyst the integration of a systemic view of the team with a generative state of mind, and the continued monitoring of the impact of this integration through a two-dimensional model that enhances the team’s productivity and positivity.

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