Double-Averaging Concept for Rough-Bed Open-Channel and Overland Flows: Applications

Vladimir Ivanovich Nikora, Stephen McLean, Stephen Coleman, Dubravka Pokrajac, Ian Kenneth McEwan, Lorna Jane Campbell, Jochen Aberle, Dougal Clunie, Katinka Koll

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124 Citations (Scopus)

Abstract

The paper briefly outlines the double-averaging methodology for studying environmental rough-bed flows. It focuses on the applications of this methodology in environmental hydraulics by providing several examples illustrating advantages of this methodology over conventional approaches. Examples include: (1) identification of specific flow layers and flow types; (2) vertical distribution of the double-averaged velocity between the roughness tops and troughs; (3) vertical distribution of momentum fluxes and sinks for typica roughness types due to turbulence, mean flow heterogeneity, secondary currents, form drag, and viscous drag; (4) estimates of form-induced (dispersive) stresses and evaluation of their structure using quadrant analysis; and (5) closure development for mass-transfer-uptake processes for stream periphyton. These examples illustrate the advantages of the double-averaging methodology over conventiona approaches as well as highlight its potential for studying flows over very rough beds, highly mobile beds, permeable beds, and surface-subsurface exchanges of mass, heat, and momentum. This methodology may also significantly improve research tools for studying a wide range of flow-biota interaction phenomena such as those related to aquatic plants, mussel communities, biofilms, and many others.

Original languageEnglish
Pages (from-to)884-895
Number of pages12
JournalJournal of Hydraulic Engineering
Volume133
Issue number8
DOIs
Publication statusPublished - Aug 2007

Keywords

  • turbulence structure
  • velocity distribution
  • sediment transport
  • stream periphyton
  • plant canopies
  • vegetation
  • model
  • layer
  • forms

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