Hydrodynamics and bed stability of open channel flows with submerged foliaged plants

M. X. Bao, Chi Wai Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

3 Citations (Scopus)

Abstract

In this work we investigate experimentally and numerically the flow structure around foliaged plants deployed in a channel with gravels on the bed under submerged and barely submerged conditions. Velocity and Reynolds stress were measured by using a NORTEK Vectrino profiler. Visual observation shows that the initial motion of gravels is easier to be triggered under the condition of flow with barely submerged vegetation. This is confirmed by the measured velocity, Reynolds stress and total kinetic energy (TKE) profiles. The velocity exhibits a speed up in the near-bed region, and the associated Reynolds stress and TKE increase there. A 3D numerical model is then verified against the experiments and used to investigate systematically the effect of degree of submergence of foliaged plants on the channel bed shear stress. The results show that the maximum bed shear stress occurs when the foliage is situated slightly below the water surface, which can enhance channel bed instability.
Original languageEnglish
Pages (from-to)815-831
Number of pages17
JournalEnvironmental Fluid Mechanics
Volume17
Issue number4
DOIs
Publication statusPublished - 1 Aug 2017

Keywords

  • Channel stability
  • Foliaged plants
  • Open-channel flow
  • Vegetation patches

ASJC Scopus subject areas

  • Environmental Chemistry
  • Water Science and Technology

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