mirage

Influence of shear stress fluctuation on bed particle mobility.

DSpace/Manakin Repository

 

Search DR-NTU


Advanced Search Subject Search

Browse

My Account

Influence of shear stress fluctuation on bed particle mobility.

Show full item record

Title: Influence of shear stress fluctuation on bed particle mobility.
Author: Cheng, Nian-Sheng
Copyright year: 2006
Abstract: Whether or not a sediment particle is entrained from a channel bed is associated with both average bed shear stress and shear stress fluctuation, the latter being flow-dependent and also related to bed irregularities. In the first part of this study, a preliminary analysis of possible fluctuations induced by bed roughness is presented for the case of an immobile plane bed comprised of unisized sediments. The result shows that the roughness-induced variation is generally comparable to that associated with near-bed turbulence, and both variations can be approximated as log-normal in terms of probability density distribution. The bed particle mobility is then analyzed by considering the effects of shear stress fluctuations. The relevant computations demonstrate that with increasing shear stress fluctuations, the probability of the mobility of a bed particle may be enhanced or weakened. For the case of low sediment entrainment, the probability is increased by turbulence. However, the probability may be reduced by the shear stress fluctuation if the average bed shear stress becomes relatively higher. This study shows that the critical condition for initial sediment motion could be overestimated if the Shields diagram is applied for the condition of flows with high turbulence intensities.
Subject: DRNTU::Engineering::Civil engineering::Water resources.
Type: Journal Article
Series/ Journal Title: Physics of fluids
School: School of Civil and Environmental Engineering
Rights: © 2006 American Institute of Physics. This paper was published in Physics of Fluids and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following DOI: [http://dx.doi.org/10.1063/1.2354434]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.
Version: Published version

Files in this item

Files Size Format View
Physics of Fluids ShearStressFluctuation.pdf 127.1Kb PDF View/Open
   

DOI Query

- Get published version (via Digital Object Identifier)
   

This item appears in the following Collection(s)

Show full item record

Statistics

Total views

All Items Views
Influence of shear stress fluctuation on bed particle mobility. 270

Total downloads

All Bitstreams Views
Physics of Fluids ShearStressFluctuation.pdf 130

Top country downloads

Country Code Views
China 43
United States of America 43
Singapore 13
Unknown Country 6
Japan 4

Top city downloads

city Views
Mountain View 30
Beijing 27
Singapore 13
Tokyo 3
Oxford 2

Downloads / month

  2014-05 2014-06 2014-07 total
Physics of Fluids ShearStressFluctuation.pdf 0 0 5 5