Turbulent Bursting-Based Sediment Entrainment Function
- 1 March 1997
- journal article
- Published by American Society of Civil Engineers (ASCE) in Journal of Hydraulic Engineering
- Vol. 123 (3), 233-236
- https://doi.org/10.1061/(asce)0733-9429(1997)123:3(233)
Abstract
One of the basic impediments to a clear understanding of a variety of fundamental problems in the context of sediment transport has been the lack of a well-grounded formulation of bed sediment entrainment. This is dealt with herein, physically based on the mechanism that bed sediment particles are actually entrained by the bursting process inherent in wall turbulent flows. A simple theoretical model for sediment entrainment from flat, loose bed is established using the averaged bursting period scaled on inner variables and the spatial scales of turbulent bursts. Sediment entrainment is shown to depend strongly on bed-shear velocity. The theoretical entrainment flux is compared to available laboratory data sets covering both hydraulically smooth and transitional bed situations. Generally good agreement is obtained, representing the best performance of the present model in relation to existing entrainment functions. It appears to characterize a rather encouraging aspect for a new approach to sediment transport, given the enhanced understanding of turbulent bursting.Keywords
This publication has 27 references indexed in Scilit:
- Coherent Motions in the Turbulent Boundary LayerAnnual Review of Fluid Mechanics, 1991
- Timescale and structure of ejections and bursts in turbulent channel flowsJournal of Fluid Mechanics, 1987
- Study of turbulent structure with hot wires smaller than the viscous lengthJournal of Fluid Mechanics, 1984
- Particle motions near the bottom in turbulent flow in an open channelJournal of Fluid Mechanics, 1978
- Sedimentological and fluid-dynamic implications of the turbulent bursting phenomenon in geophysical flowsJournal of Fluid Mechanics, 1976
- The wall region in turbulent shear flowJournal of Fluid Mechanics, 1972
- Structural features of turbulent flow over smooth and rough boundariesJournal of Fluid Mechanics, 1971
- The production of turbulence near a smooth wall in a turbulent boundary layerJournal of Fluid Mechanics, 1971
- The ‘bursting’ phenomenon in a turbulent boundary layerJournal of Fluid Mechanics, 1971
- The structure of turbulent boundary layersJournal of Fluid Mechanics, 1967