Longitudinal dispersion in wave-current-vegetation flow

S. Patil, X. Li, Chi Wai Li, B. Y.F. Tam, C. Y. Song, Y. P. Chen, Q. Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

The flow, turbulence, and longitudinal dispersion in wave-current flow through submerged vegetation are experimentally examined. Laboratory experiments are carried out by superimposing progressive waves on a steady flow through simulated submerged vegetation. The resultant wave-current-vegetation interaction shows strong interface shear with increase in the velocity due to the wave-induced drift. The increase in turbulence in the region of vegetation is found to be about twice higher than in the no-wave case due to the additional mixing by wave motions. Solute experiments are conducted to quantify the wave-current-vegetation longitudinal dispersion coefficient (WCVLDC) by the routing method and by defining length and velocity scales for the wave-current-vegetation flow. An empirical expression for the WCVLDC is proposed. Although the increase in vertical diffusivity is observed as compared with bare-bed channels, the shear effect is stronger, which increases the value of the WCVLDC. The study can be a guideline to understand the combined hydrodynamics of waves, current, and vegetation and quantify the longitudinal dispersion therein.
Original languageEnglish
Pages (from-to)45-61
Number of pages17
JournalPhysical Oceanography
Volume19
Issue number1
DOIs
Publication statusPublished - 20 Jul 2009

ASJC Scopus subject areas

  • Oceanography
  • Water Science and Technology
  • Ocean Engineering
  • Fluid Flow and Transfer Processes

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