Mobile-bed aggradation and degradation in a narrow flume: Laboratory experiments and numerical simulations

Miglio, Antonio; Gaudio, Roberto; Calomino, Francesco

doi:10.1016/j.jher.2009.01.005

Cited by 10 publications

(19 citation statements)

References 21 publications

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“…The values computed from the literature are scattered within two orders of magnitude. The formulae by [1,3] predict a trend that is consistent with the experimental one (the computed celerity increases when the measured one increases), while the predictor of [5] returns an opposite trend. In all the cases, the variability of the computed values is much less than that of the measured values.…”

Section: Front Properties: Height and Celeritysupporting

confidence: 67%

“…The celerity values determined experimentally were compared to those predicted by the formulae proposed by [1,3,4]. A constant value of celerity is returned by the formulae by [4,5], leading to an immediate comparison with the experimental values determined for the present runs. The equation by [1], instead, furnishes the length of the aggradation front as a function of time, with a time-varying front celerity.…”

Section: Front Properties: Height and Celeritymentioning

confidence: 92%

“…A new version of this predictor was later provided by [2] after running a set of overloading experiments at a constant rate, in a recirculating flume. Similar experiments were performed by [3][4][5], while [6] considered the downstream migration of sediment pulses rather than stationary sediment feeding conditions. Predictors for the downstream migration of sediment fronts were proposed by [3][4].…”

Section: Introductionmentioning

confidence: 98%

“…In this context, a key issue is the downstream migration of sediment for which a relatively scarce knowledge is available despite some experiments exist on propagation of sediment fronts [1][2][3][4][5][6]. Pioneering laboratory studies on aggradation were conducted by [1]; using uniform sand and different loading conditions, the authors proposed a predictor for the length of an aggradation front.…”

Section: Introductionmentioning

confidence: 99%

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Propagation of aggrading sediment fronts in a laboratory flume

Radice

Villota

2018

E3S Web Conf.

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Channel bed aggradation due to sediment overloading was studied experimentally. A series of aggradation tests, with uniform lightweight sediment, were performed to observe the hydro-morphologic response of a laboratory flume to bed-load sediment transport and nonequilibrium upstream sediment feeding. The hydro-dynamic and the sediment feeding rates were kept constant in time. The temporal evolution of the longitudinal profiles of the stream bed and of the water surface was measured by imaging methods. The experimental data were used to (i) provide a phenomenological description of the aggradation process, recognizing different morphologic features superimposed on one another and (ii) characterize the height and velocity of propagation of aggrading sediment fronts. The front heights increased with increasing sediment supply, while the front celerity decreased. The celerity values were compared to a few predictors available in the literature. The literature formulae return celerity values scattered over almost two orders of magnitude, and present conflicting trends (a predicted celerity may either increase or decrease for increasing sediment feeding rate), thus stimulating further research on the topic.

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Section: Front Properties: Height and Celeritysupporting

confidence: 67%

Section: Front Properties: Height and Celeritymentioning

confidence: 92%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Propagation of aggrading sediment fronts in a laboratory flume

Radice

Villota

2018

E3S Web Conf.

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“…Physical models can be considered as effective tools for testing sediment transport formulae and investigating the processes of river morphology evolution in watersheds (Darby et al 2002). In recent decades, numerical models have been developed to simulate the bed load discharge based on the combination of laboratory survey and numerical models (Guan et al 2016;Miglio et al 2009). Several studies stated that calculating the sediment transport rate in channels, especially estimating the bed load transport rate in meandering channels, which results in geomorphic changes, is extremely difficult and very expensive.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation and Numerical Simulation of Morphological Changes in Natural Channel Bend

Lee¹,

Dang

2018

JAFM

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Sediment transport is an important process in maintaining balance of the form of river. The transport of bed load particles affects the processes of aggradation and degradation of the riverbed significantly. To predict the evolution process of the river morphology, the numerical model is considered as a useful tool. This study developed a two-dimensional (2D) depth-averaged model for the morphological change in the river bend. The flow module is represented by the shallow water equations, and the river morphological changes are represented by the sediment continuity equation. The sediment transport module treats bed load as mixtures of multiple grain-size sediments. A finite difference method was applied to solving the governing equations. The developed model was applied to predict bed-load transport rate on one set of the laboratory experiment. A field study was further applied to demonstrate the capability of the developed model in predicting morphological change in the curved river section in South Korea. The simulation results of the developed model were in good agreement with field data both laboratory experiment and natural channel bend.

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Numerical Analysis for Particle Deposit Formation in Reactor Cyclone of Residue Fluidized Catalytic Cracking

Cho

Cha

Kim

et al. 2013

Ind. Eng. Chem. Res.

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Computational particle fluid dynamics (CPFD) simulation was carried out to analyze flow patterns in order to understand the mechanism of deposit formation on the cyclone duct during the residue fluidized catalytic cracking (RFCC) process. The CPFD simulation was based on the multiphase particle-in-cell (MP-PIC) method, in which the particle phase was solved by the stochastic Lagrangian model and the fluid phase was analyzed by the Eulerian method. In the first stage, a lowspeed zone at a duct angle of 90°(an inlet position of 0°) was discovered in the basic design of the cyclone, and this zone was predicted to be the initial region of deposit. Case studies were carried out for several stages of deposit growth to investigate the effects of deposit size on cyclone performance. A scouring phenomenon which hampers deposit growth is expected to occur when the deposit reaches 90 mm in thickness. When the deposit reaches 150 mm, the carryover rate abruptly doubles.

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Mobile-bed aggradation and degradation in a narrow flume: Laboratory experiments and numerical simulations

Cited by 10 publications

References 21 publications

Propagation of aggrading sediment fronts in a laboratory flume

Propagation of aggrading sediment fronts in a laboratory flume

Experimental Investigation and Numerical Simulation of Morphological Changes in Natural Channel Bend

Numerical Analysis for Particle Deposit Formation in Reactor Cyclone of Residue Fluidized Catalytic Cracking

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