Next Article in Journal
Evapotranspiration in the Nile Basin: Identifying Dynamics and Drivers, 2002–2011
Next Article in Special Issue
Dynamic Lift on an Artificial Static Armor Layer During Highly Unsteady Open Channel Flow
Previous Article in Journal
Wastewater Treatment and Reuse: Past, Present, and Future
Previous Article in Special Issue
Integrated River and Coastal Flow, Sediment and Escherichia coli Modelling for Bathing Water Quality
Article Menu

Export Article

Open AccessArticle
Water 2015, 7(9), 4896-4913; doi:10.3390/w7094896

Secondary Currents and Turbulence over a Non-Uniformly Roughened Open-Channel Bed

School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
*
Author to whom correspondence should be addressed.
Academic Editor: Miklas Scholz
Received: 29 July 2015 / Revised: 28 August 2015 / Accepted: 1 September 2015 / Published: 9 September 2015
(This article belongs to the Special Issue Recent Advances in Riverflow Research)
View Full-Text   |   Download PDF [2382 KB, uploaded 9 September 2015]   |  

Abstract

Large-eddy simulations (LES) of the flow over a non-uniformly roughened channel bed are carried out to study the effect of non-uniform bed roughness on turbulence driven secondary currents and turbulence statistics. The channel bed is comprised of alternating rough and smooth strips, the width of which corresponds to the water depth. The Reynolds number based on hydraulic radius and bulk velocity is 34,000. The LES are successfully validated using experimental data. The secondary flow and bed roughness have a significant effect on the streamwise velocity and second order turbulence statistics. Turbulence is enhanced over rough strips and suppressed over smooth strips. Significant lateral momentum transfer takes place due to both advection and turbulence. The bed shear stresses over the smooth strips are approximately four times less than over the rough strips a result of near bed low momentum fluid being transported from the rough strips to the smooth strips and high momentum fluid being convected from the surface towards the bed. The most significant terms in the streamwise momentum equation are quantified and discussed with regard to momentum transfer. View Full-Text
Keywords: : turbulence; bed roughness; large-eddy simulation; secondary currents : turbulence; bed roughness; large-eddy simulation; secondary currents
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Stoesser, T.; McSherry, R.; Fraga, B. Secondary Currents and Turbulence over a Non-Uniformly Roughened Open-Channel Bed. Water 2015, 7, 4896-4913.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top