Turbulent kinetic energy budgets in a model canopy: Comparisons between LES and wind-tunnel experiments

Wusi Yue, Charles Meneveau, Marc B. Parlange, Weihong Zhu, Hyung Suk Kang, Joseph Katz

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31 Citations (Scopus)

Abstract

A comparative study of turbulence in a wind-tunnel model canopy is performed, using Large eddy simulation (LES) and experimental data from PIV and hot-wire anemometry measurements. The model canopy is composed of thin cylindrical stalks. In the LES, these are represented using a plant-scale approach, while the scale-dependent Lagrangian dynamic model is used as subgrid-scale model. LES predictions of turbulence statistics and energy spectra are found to be in good agreement with the experimental data. Turbulent kinetic energy (TKE) budgets from the LES simulation are analyzed to provide more information absent in the measurements. Results confirm that sloshing motions at the low levels of the canopy are mainly driven by pressure fluctuations. A difference between the energy flux obtained from the energy spectrum and the SGS dissipation rate is observed, consistent with a spectral bypass mechanism in which the real spectral flux due to cascade is smaller than that implied by the energy-spectrum level, due to direct drain by the canopy.

Original languageEnglish
Pages (from-to)73-95
Number of pages23
JournalEnvironmental Fluid Mechanics
Volume8
Issue number1
DOIs
Publication statusPublished - Feb 2008
Externally publishedYes

Keywords

  • Energy spectrum
  • Hotwire anemometer
  • Large eddy simulation
  • Particle image velocimetry
  • Turbulent kinetic energy budget
  • Wind-tunnel model canopy

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