LES Simulation of Turbulent Flow within and above a Vegetation Canopy Using Non-linear Subgrid-scale Parameterization

Yong Shi, Kyaw Tha Paw U, Bai Yang, Branko Kosovic and Roger Shaw Department of Land, Air and Water Resources, University of California, Davis, CA 95616

Abstract

An initial attempt of using a LES model with nonlinear parameterization of subgrid-scale variables to simulate atmospheric boundary layer (ABL) flow structure under a neutral stratified condition is performed in this research. The mean flow field was obtained. Through changing the boundary conditions and surface conditions, we also study the boundary layer structure within and over a vegetation canopy. The results show that the wind and turbulence profiles are basically consistent with the general boundary layer theories, and the model has strong ability for modeling the vegetation boundary layer.

Key words: LES modeling, nonlinear subgrid-scale parameterization, ABL, vegetation canopy