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Large Eddy Simulations of Model-Scale Turbulent Atmospheric Boundary Layer Flows
1NIST Director's Postdoctoral Fellow, Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899.
Journal of Engineering Mechanics
|April 11, 2025
Summary
Large eddy simulations (LES) accurately represent atmospheric boundary layer (ABL) turbulence statistics for structural engineering. While simple models show limitations near the ground, they capture key flow physics effectively.
Area of Science:
- Fluid Dynamics
- Atmospheric Science
- Computational Engineering
Background:
- Atmospheric boundary layer (ABL) flows are critical for structural engineering applications.
- Accurate simulation of ABL turbulence is essential for reliable structural design.
- Previous studies highlight the need for validated simulation methods for ABL flows.
Purpose of the Study:
- To perform large eddy simulations (LES) of model-scaled, neutrally stratified ABL flows.
- To analyze the statistical properties of simulated ABL turbulence.
- To assess the suitability of LES with simple subgrid-scale (SGS) and wall models for structural engineering.
Main Methods:
- Employed large eddy simulations (LES) for neutrally stratified ABL flows.
- Utilized a one-k-equation eddy model for subgrid-scale (SGS) motions.
- Implemented a wall shear model to represent ground effects.
Main Results:
- The mean streamwise velocity profile exhibited a logarithmic trend, with minor deviations near the ground due to SGS model limitations.
- Turbulence second moments accurately reflected the underlying physical processes.
- Velocity component spectra and spatial coherences aligned with established theoretical expressions.
Conclusions:
- Large eddy simulations (LES) with basic SGS and wall models effectively represent ABL turbulence statistics.
- These simulations are suitable for structural engineering applications, with noted limitations in accurately predicting mean velocity near the ground.
- The study validates LES as a powerful tool for analyzing ABL flows in engineering contexts.
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