Boltzmann Distribution of Sediment Transport.
Reads0
Chats0
TLDR
This work tracks particles in a laboratory flume to relate their statistical behavior to the self-organization of the granular bed they make up, and finds that as they travel downstream, the transported grains wander randomly across the bed's surface, thus inducing cross-stream diffusion.Abstract:
The coupling of sediment transport with the flow that drives it allows rivers to shape their own bed. Cross-stream fluxes of sediment play a crucial, yet poorly understood, role in this process. Here, we track particles in a laboratory flume to relate their statistical behavior to the self-organization of the granular bed they make up. As they travel downstream, the transported grains wander randomly across the bed's surface, thus inducing cross-stream diffusion. The balance of diffusion and gravity results in a peculiar Boltzmann distribution, in which the bed's roughness plays the role of thermal fluctuations, while its surface forms the potential well that confines the sediment flux.read more
Citations
More filters
Journal of Fluid Mechanics创刊50周年
TL;DR: The mysterious rattleback and its fluid counterpart：Developments in shear instabilities（Patrick Huerre，Falling clouds＋Elisabeth Guazzelli）ＬEcotectural fluid mechanics％Herbert Huppert ）
The Nature of Saltation and of Bed-Load Transport in Water
TL;DR: In this article, it has been shown that suspension by fluid turbulence of mineral solids larger than those of medium sands does not become appreciable until the bed shear stress is increased to a value exceeding 12 times its threshold value for the bed material considered.
Journal ArticleDOI
Laboratory rivers adjust their shape to sediment transport.
TL;DR: It is shown that, at equilibrium, the river shapes its channel so that the intensity of sediment transport follows a Boltzmann distribution, which selects a well-defined width over which the river transports sediment, while the sediment remains virtually idle on its banks.
Journal ArticleDOI
Probability Distributions of Particle Hop Distance and Travel Time Over Equilibrium Mobile Bedforms
TL;DR: In this paper, the authors present measurements of particle motion over bedform topography obtained in a laboratory flume and compare these to particle motions over plane bed topography with otherwise similar conditions.
Journal ArticleDOI
Growth of barchan dunes of bidispersed granular mixtures.
TL;DR: In this article, the authors investigated the growth of subaqueous barchans consisting of bidisperse grains and found that the grain distribution within the dune changes with the employed pair.
References
More filters
Journal ArticleDOI
Erosion and deposition of particles on a bed sheared by a viscous flow
F. Charru,H. Mouilleron,O. Eiff +2 more
TL;DR: In this paper, the authors studied the dynamics of a bed of particles sheared by a viscous Couette flow in an annular channel, with emphasis on the distributions of particle velocities, durations and lengths of small saltation flights, and surface density of the moving particles.
Journal ArticleDOI
A new vectorial bedload formulation and its application to the time evolution of straight river channels
Agnes Kovacs,Gary Parker +1 more
TL;DR: In this article, the authors derived a new vectorial bedload formulation for the transport of coarse sediment by fluid flow, which is fully nonlinear and vectorial in nature, in addition, it behaves smoothly up to the angle of repose.
Journal ArticleDOI
Deformation and flow of a two-dimensional foam under continuous shear.
TL;DR: A stochastic model is proposed where bubbles rearrangements are activated by local stress fluctuations produced by the shearing wheel and this model gives a complete description of the observations and is also consistent with available data on granular shear bands.
Journal ArticleDOI
Collisional sheet flows of sediment driven by a turbulent fluid
James T. Jenkins,Daniel M. Hanes +1 more
TL;DR: In this paper, the authors consider a sheet flow in which heavy grains near a packed bed interact with a unidirectional turbulent shear flow of a fluid and employ a relatively simple model of the turbulent shearing of the fluid and use kinetic theory for the collisional grain flow to predict profiles of the mean fluid velocity, the mean particle velocity, and the particle concentration.
Journal ArticleDOI
A probabilistic description of the bed load sediment flux: 1. Theory
TL;DR: In this article, the authors provide a probabilistic definition of the bed load sediment flux, which is consistent with experimental measurements and simulations of particle motions reported in companion papers, and the formulation is based on the Fokker-Planck equation (an advection-diffusion form of the Master equation).