Modeling of Sediment Transport in Steady Flow over Mobile Granular Bed

For the channel regulation in tidal rivers, groins are often used as typical hydraulic structures. Precisely predicting the local scour depth at the groin head is the key for the project of river regulation. The local scour of groins for tidal rivers is significantly different from that for the undirectional steady flow of general rivers. In the present paper, a three-dimendional (3D) mathematical model for turbulence and sediment transport are establishmented. The local scour near the groin under the actions of tidal current and steady flow are simulated by established 3D turbulence and sediment transport numerical model.The differences of the scour development and the scour pattern near the groin under these two actions are compared.

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Numerical Calculations with a Multi-layer Model of Mixed Sand Transport Against Measurements in Wave Motion and Steady Flow

Rocznik Ochrona Środowiska ◽

10.54740/ros.2021.044 ◽

2021 ◽

Vol 23 ◽

pp. 629-641

Author(s):

Leszek M. Kaczmarek

Keyword(s):

Sediment Transport ◽

Steady Flow ◽

Large Scale ◽

Wave Motion ◽

Numerical Calculations ◽

Wave Crest ◽

Sand Transport ◽

Layer Model ◽

Model Concept ◽

Grain Size Distributions

A multi-layer model is used to calculate time-dependent sediment velocity and concentration vertical profiles. This model, in which the differences in sediment transport at different distances from the bed are considered is intended both for the wave motion and steady flow. Numerical calculations were carried out for sediment transport during the wave crest and trough and total sediment transport as a sum of their absolute values. The model concept of variation in shear stress from the skin stress value above the bed to the stress value at the bed previously proposed for steady flow is extended here for the wave motion and verified by direct stress measurements. The calculations were carried out for mixed sand sediments with different grain size distributions including semi-uniform and poorly sorted grains. Comparison with the available small- and large -scale data from flumes and oscillating tunnels yields agreement typically within plus/minus a factor two of measurements.

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Prediction of Overtopping Dike Failure: Sediment Transport and Dynamic Granular Bed Deformation Model

Journal of Hydraulic Engineering ◽

10.1061/(asce)hy.1943-7900.0001608 ◽

2019 ◽

Vol 145 (6) ◽

pp. 04019021 ◽

Cited By ~ 2

Author(s):

Francisco Nicolás Cantero-Chinchilla ◽

Oscar Castro-Orgaz ◽

Subhasish Dey

Keyword(s):

Sediment Transport ◽

Deformation Model ◽

Granular Bed ◽

Bed Deformation ◽

Dike Failure

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Direct numerical simulations of flow over two-dimensional and three-dimensional ripples and implication to sediment transport: Steady flow

Coastal Engineering ◽

10.1016/j.coastaleng.2008.09.010 ◽

2009 ◽

Vol 56 (3) ◽

pp. 320-331 ◽

Cited By ~ 13

Author(s):

Kiran Bhaganagar ◽

Tian-Jian Hsu

Keyword(s):

Sediment Transport ◽

Numerical Simulations ◽

Steady Flow ◽

Three Dimensional ◽

Direct Numerical Simulations ◽

Two Dimensional

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Experimental Study on Uniform and Mixed Bed-Load Sediment Transport under Unsteady Flow

Applied Sciences ◽

10.3390/app10062002 ◽

2020 ◽

Vol 10 (6) ◽

pp. 2002

Author(s):

Zihao Duan ◽

Jie Chen ◽

Changbo Jiang ◽

Xiaojian Liu ◽

Bingbing Zhao

Keyword(s):

Particle Size ◽

Sediment Transport ◽

Unsteady Flow ◽

Steady Flow ◽

Transport Rate ◽

Bed Load ◽

Sediment Transport Rate ◽

Particle Size Ratio ◽

Load Movement ◽

Sediment Particles

The scouring and deposition of sediment caused by unsteady flows (e.g., storm waves and floods) produces many secondary disasters. The resultant bed-load movement exhibits different transport laws compared with that by steady flow. In this study, the flume experiments were performed to study the bed-load movement under unsteady flow with different velocity skewness. The movement of uniform and non-uniform non-cohesive sediment under unsteady flow as well as the influence of the steady and unsteady flow on sediment transport rate are compared. Additionally, the non-uniform sediment transport formula of fine-to-coarse particle diameter ratio was investigated. The results showed that the sediment transport rate between uniform and non-uniform sand under the same median diameter is different. The non-uniform sediment transport rate is 1.27-, 3.19-, and 0.68-times as large as that in uniform sediment under d50 = 0.664, 1.333, and 2.639 mm under unsteady flow, respectively. For non-uniform sand, the transport rate of non-uniform sand with a larger adjacent particle size ratio (δ = 0.29) was 1.31-times greater than that of the non-uniform sand with a smaller adjacent particle size ratio (δ = 0.50). Moreover, theoretical deduction was carried out and the incipient sediment motion was analyzed from the force mechanism. A new unsteadiness parameter based on the acceleration concept was proposed. The relationship between the travel distance and velocity skewness of sediment particles was set up. The experimental results and theoretical analysis showed that sediment under unsteady flow were easier to start and transport than those under steady flow in the same flow effect. The travel distance of sediment particles was longer under unsteady flow than that under steady flow.

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Erratum for “Prediction of Overtopping Dike Failure: Sediment Transport and Dynamic Granular Bed Deformation Model” by Francisco Nicolás Cantero-Chinchilla, Oscar Castro-Orgaz, and Subhasish Dey

Journal of Hydraulic Engineering ◽

10.1061/(asce)hy.1943-7900.0001790 ◽

2020 ◽

Vol 146 (8) ◽

pp. 08220002

Author(s):

Francisco Nicolás Cantero-Chinchilla ◽

Oscar Castro-Orgaz ◽

Subhasish Dey

Keyword(s):

Sediment Transport ◽

Deformation Model ◽

Granular Bed ◽

Bed Deformation ◽

Dike Failure

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Sensitivity Analysis Of Geographical River Boundary Layers

Journal of Geographical Research ◽

10.30564/jgr.v2i2.632 ◽

2019 ◽

Vol 2 (2) ◽

Author(s):

Levent Yilmaz

Keyword(s):

Sensitivity Analysis ◽

Sediment Transport ◽

Steady Flow ◽

Boundary Layers ◽

Frequency Of Occurrence ◽

Gravel Bed ◽

Channel Shape ◽

Gravel Bed Rivers

Bank full discharge is generally considered to be the dominant steady flow which would generate the same regime channel shape and dimensions as the natural sequences of flows would. This is because investigation on the magnitude and frequency of sediment transport have determined that for stable rivers the flow which in the longer term transports most material has the same frequency of occurrence as bankfull flow. For stable gravel-bed rivers, this is considered to be the 1.5-year flood.

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Taking into account granular bed resistance in turbulent bedload transport with arbitrary slope and particle shape

10.5194/egusphere-egu2020-21795 ◽

2020 ◽

Author(s):

Raphaël Maurin ◽

Remi Monthiller ◽

Laurent Lacaze

Keyword(s):

Sediment Transport ◽

Particle Shape ◽

Granular Media ◽

Element Model ◽

Bedload Transport ◽

Transport Rate ◽

Major Influence ◽

Granular Bed ◽

Sediment Transport Rate ◽

Shape Influence

Turbulent bedload transport has a major influence for riverbed evolution and is still lacking a general understanding for realistic configurations with arbitrary slopes and sediments shapes. In this contribution, we explore the importance of the granular bed resistance to the fluid flow. Based on the work of Maurin et al (2018), we show that a generalized version of the repose angle of the granular material can be defined, and is able to characterize the slope influence on sediment transport rate for particle scale simulations (Maurin et al, 2015) over a large range of slopes and fluid forcing (i.e. Shields number). Extending the configuration to arbitrary particle shapes, the sediment transport rate is shown to be correlated to the variation of the granular media repose angle (Monthiller 2019), and the relevance of the latter is discussed.Maurin, R., Chauchat, J., Chareyre B. & Frey, P. (2015). A minimal coupled fluid-discrete element model for bedload transport, Physics of Fluids, 27, 113302 Maurin, R., Chauchat, J., & Frey, P. (2018). Revisiting slope influence in turbulent bedload transport: Consequences for vertical flow structure and transport rate scaling. Journal of Fluid Mechanics, 839, 135-156. doi:10.1017/jfm.2017.903 Monthiller, R. (2019), Particle shape influence on turbulent bedload transport, Master thesis ENSEEIHT/Toulouse Univ.

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