Using Lagrangian particle saltation observations for bedload sediment transport modelling

Niño, Yarko; García, Marcelo H.

doi:10.1002/(sici)1099-1085(19980630)12:8<1197::aid-hyp612>3.0.co;2-u

Cited by 129 publications

(92 citation statements)

References 31 publications

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“…6 and 7 herein, we compare numerical results obtained with our code [4,17,18] against data collected by [32,34], for the cases of gravels and sands moving in saltation, respectively. Results indicate that whereas the Basset force is negligible for the range of sizes of gravels moving as bed-load [33], the force becomes very important for sands [35]. In the latter case, the length of a single particle jump can be under-predicted by about 40 % if the force is omitted, and the jump height can be under-predicted by about 15 % [4].…”

Section: Rate Of Convergence and Accuracymentioning

confidence: 96%

“…However, it has been recently found that the Basset force becomes important when the particles are relatively small [4,35] as follows. In Figs.…”

Section: Rate Of Convergence and Accuracymentioning

confidence: 99%

“…Another important difficulty regarding the numerical integration of the Basset term is the singularity encountered when the upper limit is enforced in the integrand. The difficulties introduced by the Basset term have induced many authors to either completely disregard it from the particle equation of motion or to consider it negligible, which may lead to large computational errors for small particles [4,35]. This paper critically compares major recent advances brought by four works: [4,12,13,46], which involve a fractional derivative approach, window kernels and higher-order numerical integration schemes.…”

Section: Introductionmentioning

confidence: 99%

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Computation of the Basset force: recent advances and environmental flow applications

Moreno-Casas

Bombardelli

2015

Environ Fluid Mech

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When numerically integrating the equation describing the motion of a particle in a carrier fluid, the computation of the Basset (history) force becomes by far the most expensive and cumbersome, as opposed to forces such as drag, virtual mass, lift, buoyancy and Magnus. The expression representing the Basset force constitutes an integro-differential term whose standard integrand is singular when the upper integration limit is enforced. These shortcomings have led some researchers to either disregard or outright neglect the contribution of the Basset force to the total force, even in those cases where it may yield to important errors in the determination of particle trajectories in the computation of sediment transport and other environmental flows. This work is devoted to review four recent contributions associated with the computation of the Basset force, and to compare their proposals to diminish the inherent problems of the term integration. All papers, except one, use variants of a window-based approach; the most recent contribution, in turn, employs a specialized quadrature to increase the accuracy of the computation. An analysis was carried out to compare CPU computation times, rates of convergence and accuracy of the approximations versus a known analytical solution. All methods provide sound solutions to the issues associated with the computation of the Basset force; further, a road map to select the best solution for each given problem is provided. Finally, we discuss the implications of the techniques for the simulation of sediment transport processes and other environmental flows.

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Section: Rate Of Convergence and Accuracymentioning

confidence: 96%

“…However, it has been recently found that the Basset force becomes important when the particles are relatively small [4,35] as follows. In Figs.…”

Section: Rate Of Convergence and Accuracymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Computation of the Basset force: recent advances and environmental flow applications

Moreno-Casas

Bombardelli

2015

Environ Fluid Mech

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“…The speed of a particle undergoing bedload transport has been estimated between 1/4 and 1/7 of the depth-averaged flow velocity (Bilgili et al 2003;Bogardi 1974). A more rigorously derived formula by Niño and García (1998) is based on experimental and numerical analyses that relate the dimensionless streamwise particle velocity, u s , to the dimensionless bed shear, τ * .…”

Section: Jump Lengthmentioning

confidence: 99%

“…Therefore, the mean grain size and density of the sediment are used to calculate the average particle speed rather than that of the individual bivalves. The model results presented here use this formulation of jump length and parameter estimates derived by Niño and García (1998). These empirical estimates indirectly depend upon the critical shear stress of the sediment (critical erosion velocity of site 1 sediment 1.65 cm s −1 ; Hunt unpubl.…”

Section: Jump Lengthmentioning

confidence: 99%

Modeling Bedload Transport of Juvenile Bivalves: Predicted Changes in Distribution and Scale of Postlarval Dispersal

Hunt

Fugate

Chant

2009

Estuaries and Coasts

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The potential consequences of bedload transport of postlarvae for patterns of distribution of marine invertebrates were explored by developing a bedload transport model for juvenile bivalves in a small estuary in New Jersey, USA. A simple numerical model of tidal current hydrodynamics was developed based on field measurements of shear stresses near the bottom. Burrowing behavior of bivalves was incorporated into the model of bedload transport by using estimates of entrainment rates of Gemma gemma and Mya arenaria in a laboratory flume, and jump lengths of the bivalves were estimated by methods previously developed for noncohesive particles. Based on the flood domination and strong gradient of shear stresses in the Navesink estuary, our model predicted that juvenile bivalves would accumulate in the center of the estuary, traveling up to several kilometers over 30 days. Field distributions of juvenile bivalves were consistent with the model predictions for other species of bivalves but not for G. gemma, for which field distributions of both <500-and >500-μm individuals were concentrated in the eastern end of the estuary. Differences between the bedload model and G. gemma distributions suggest that spatial variation in burrowing behavior or biological interactions are playing an important role in maintaining distribution patterns of this species in spite of high levels of bedload transport. This modeling approach is applicable to other juvenile benthic invertebrates that disperse as bedload and is a useful model against which to compare field observations of rates of transport and patterns of distribution and abundance.

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A mechanistic-stochastic formulation of bed load particle motions: From individual particle forces to the Fokker-Planck equation under low transport rates

Fan

Zhong

Wang

et al. 2014

J. Geophys. Res. Earth Surf.

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Bed load transport is a highly complex process. The probability density function (PDF) of particle velocities results from the local particle momentum variability in response to fluid drag and interactions with the bed. Starting from the forces exerted on a single particle under low transport rates (i.e., rolling and sliding regimes), we derive here the nonlinear stochastic Langevin equation (LE) to describe the dynamics of a single particle, accounting for both the deterministic and the stochastic components of such forces. Then, the Fokker-Planck equation (FPE), which describes the evolution of the PDF of the ensemble particle velocities, is derived from the LE. We show that the theoretical PDFs of both streamwise and cross-stream velocities obtained by solving the FPE under equilibrium conditions have exponential form (PDFs of both positive and negative velocities decay exponentially), consistent with the experimental data by Roseberry et al. (2012). Moreover, we theoretically show how the exponential-like PDF of an ensemble of particle velocities results from the forces exerted on a single particle. We also show that the simulated particle motions using the proposed Langevin model exhibit an emergent nonlinear relationship between hop distances and travel times (power law with exponent 5/3), in agreement with the experimental data, providing a statistical description of the particles' random motion in the context of a stochastic transport process. Finally, our study emphasizes that the motion of individual particles, described by the LE, and the behavior of the ensemble, described by the FPE, are connected within a statistical mechanics framework.

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Using Lagrangian particle saltation observations for bedload sediment transport modelling

Cited by 129 publications

References 31 publications

Computation of the Basset force: recent advances and environmental flow applications

Computation of the Basset force: recent advances and environmental flow applications

Modeling Bedload Transport of Juvenile Bivalves: Predicted Changes in Distribution and Scale of Postlarval Dispersal

A mechanistic-stochastic formulation of bed load particle motions: From individual particle forces to the Fokker-Planck equation under low transport rates

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