scholarly journals Two-dimension coupling model to simulate water flow, sediment transport and bed evolution

2016 ◽  
Vol 48 (6) ◽  
pp. 1537-1553
Author(s):  
Wei Liu ◽  
Siming He ◽  
Qiang Xu
Keyword(s):  
Sediment Transport ◽  
Velocity Profile ◽  
Water Flow ◽  
Morphological Evolution ◽  
Fixed Bed ◽  
Coupling Model ◽  
Momentum Conservation ◽  
Two Dimension ◽  
Bed Evolution ◽  
Flow Mobility

Abstract Catastrophic flood events worldwide have become increasingly more frequent and their dynamics mechanism has attracted much interest as how to predict them by numerical method. As the most common phenomenon occurs in the flowing process, entrainment and deposition can significantly influence flow mobility by increasing in mass and changing in flow character. In this paper, a two-dimension coupling model is presented to simulate water flow, sediment transport and bed evolution based on the shallow water assumption, depth-averaged integration as well as morphological evolution. A new term accounting for the sediment effect on the momentum conservation of water–sediment mixture is added to the model equations by assuming that the flow and the fixed bed is connected by an infinitesimally thin boundary layer, in which the erodible material gains the necessary velocity to enter the flow above. Comparison of numerical results and experimental data indicate the presented model can adequately describe the complex dynamic process, sediment transport and bed evolution. The velocity profile of flow can influence the momentum transfer between the water column and the erodible bottom boundary due to sediment exchange, further influencing flow mobility. Moreover, the velocity profile of flow changes with variations of sediment concentration, bed surface and friction resistance.

scholarly journals An improved coupling model for water flow, sediment transport and bed evolution (CASFE v.1)

2014 ◽  
Vol 7 (2) ◽  
pp. 2429-2454
Author(s):  
S. He ◽  
W. Liu ◽  
X. Li ◽  
C. Ouyang
Keyword(s):  
Sediment Transport ◽  
Water Flow ◽  
Morphological Evolution ◽  
Coupling Model ◽  
Chinese Academy Of Sciences ◽  
Bed Evolution ◽  
The One ◽  
Volume Method ◽  
Academy Of Sciences ◽  
Sediment Mixtures

Abstract. This paper presents a new coupling model to simulate water flow, sediment transport and bed evolution based on the shallow water assumption, depth-average integration as well as the morphological evolution (Chinese Academy of Sciences flow-erosion model, CASFE). The model takes account of the effects of rainfall, entrainment and deposition on the motion of water–sediment mixtures. Limitations and drawbacks of other authors' models are pointed out according to the comparison among these models. The finite volume method has been adopted to solve the one-dimensional dam-break problem considering an erodible bed. Numerical results indicate that the model can adequately describe the complex dynamic problems. Simulation results demonstrate that the entrainment and deposition significantly affects the flow dynamics and morphological evolution.

Investigation of the influence of the flow structure on the accuracy of flow measurement before a hydrometric structure in an open channel

2020 ◽  
pp. 41-44
Author(s):  
Anatoly Kusher
Keyword(s):  
Velocity Profile ◽  
Flow Velocity ◽  
Water Flow ◽  
Flow Measurement ◽  
Water Discharge ◽  
Critical Depth ◽  
Flow Measurements ◽  
Study Results ◽  
Flow Velocity Profile ◽  
Upstream Flow

The reliability of water flow measurement in irrigational canals depends on the measurement method and design features of the flow-measuring structure and the upstream flow velocity profile. The flow velocity profile is a function of the channel geometry and wall roughness. The article presents the study results of the influence of the upstream flow velocity profile on the discharge measurement accuracy. For this, the physical and numerical modeling of two structures was carried out: a critical depth flume and a hydrometric overfall in a rectangular channel. According to the data of numerical simulation of the critical depth flume with a uniform and parabolic (1/7) velocity profile in the upstream channel, the values of water discharge differ very little from the experimental values in the laboratory model with a similar geometry (δ < 2 %). In contrast to the critical depth flume, a change in the velocity profile only due to an increase in the height of the bottom roughness by 3 mm causes a decrease of the overfall discharge coefficient by 4…5 %. According to the results of the numerical and physical modeling, it was found that an increase of backwater by hydrometric structure reduces the influence of the upstream flow velocity profile and increases the reliability of water flow measurements.

Sediment transport over fixed deposited beds in sewers - An appraisal of existing models

1997 ◽  
Vol 36 (8-9) ◽  
pp. 123-128 ◽  
Author(s):  
C. Nalluri ◽  
A. K. El-Zaemey ◽  
H. L. Chan
Keyword(s):  
Sediment Transport ◽  
Fixed Bed ◽  
Transport Equations ◽  
Design Criterion ◽  
Pipe Diameter ◽  
Transport Velocity

An appraisal of the existing sediment transport equations was made using May et al (1989) and Ackers (1991) sediment transport equations for the limit of deposition design criterion and with a deposit depth of 1% of the pipe diameter allowed in the sewers. The applicability of those equations for sewers with larger fixed bed deposit depth was assessed, the equations generally over-estimated the transport velocity. Modifications were made to enable the equations to apply to sewers with large fixed bed deposits present.

A novel fluid–solid coupling model for the oil–water flow in the natural fractured reservoirs

2021 ◽  
Vol 33 (3) ◽  
pp. 036601
Author(s):  
Dongxu Zhang ◽  
Liehui Zhang ◽  
Huiying Tang ◽  
Shuwu Yuan ◽  
Hui Wang ◽  
...  
Keyword(s):  
Water Flow ◽  
Fractured Reservoirs ◽  
Coupling Model ◽  
Oil Water

scholarly journals Sediment Transport and Water Flow Resistance in Alluvial River Channels: Modified Model of Transport of Non-Uniform Grain-Size Sediments

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2038
Author(s):  
Gennady Gladkov ◽  
Michał Habel ◽  
Zygmunt Babiński ◽  
Pakhom Belyakov
Keyword(s):  
Sediment Transport ◽  
Water Flow ◽  
Transport Model ◽  
Flow Characteristics ◽  
Field Measurements ◽  
Field Investigation ◽  
Empirical Modeling ◽  
River Channels ◽  
Channel Deformations ◽  
East European

The paper presents recommendations for using the results obtained in sediment transport simulation and modeling of channel deformations in rivers. This work relates to the issues of empirical modeling of the water flow characteristics in natural riverbeds with a movable bottom (alluvial channels) which are extremely complex. The study shows that in the simulation of sediment transport and calculation of channel deformations in the rivers, it is expedient to use the calculation dependences of Chézy’s coefficient for assessing the roughness of the bottom sediment mixture, or the dependences of the form based on the field investigation data. Three models are most commonly used and based on the original formulas of Meyer-Peter and Müller (1948), Einstein (1950) and van Rijn (1984). This work deals with assessing the hydraulic resistance of the channel and improving the river sediment transport model in a simulation of riverbed transformation on the basis of previous research to verify it based on 296 field measurements on the Central-East European lowland rivers. The performed test calculations show that the modified van Rijn formula gives the best results from all the considered variants.

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