Large Eddy Simulations of Model-Scale Turbulent Atmospheric Boundary Layer Flows

摘要

This paper presents large eddy simulations (LES) of model-scaled neutrally stratified atmospheric boundary layer (ABL) flows for structural engineering applications and examines their statistical properties. A one-k-equation eddy model is used for the subgrid-scale (SGS) motions, and a wall shear model is applied on the ground. The mean streamwise velocity profile is approximately logarithmic, yet near the ground a mismatch persists because of the limited accuracy of the SGS model. The second moments of the turbulence represent well the underlying physics. The spectra of the velocity components at a point are consistent with commonly accepted expressions. The spatial coherences decay exponentially as functions of reduced frequencies. The results suggest that, except for the mean velocity near the ground, the ABL turbulence statistics can be well represented by large eddy simulations with simple SGS and wall models. (C) 2017 American Society of Civil Engineers.