Simulation of wind gust structure in the atmospheric boundary layer with Lattice Boltzmann Method

Authors:
CHENG XueLing, HU Fei^* & ZENG QingCun
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

Abstract:

Cold fronts occur in northern East Asia during winter and spring. After cold frontal passage, airflow is downward and accompa-nying strong winds fluctuate significantly; this is termed wind gusts. Analysis of observation data shows that wind gust structure has coherent characteristics. This is important for entrainment of spring dust storms into the upper boundary layer, where they are transported great distances. The Lattice Boltzmann Method (LBM) is a computational  fluid technique based on the Boltzmann transport equation. The LBM has been used to study complex motion such as turbulence, because it describes motion at the micro level. In this paper, Large eddy simulation is introduced in the LBM, enabling simulation of turbulent flow in the atmospheric boundary layer. The formation and development of wind gusts are simulated, and a coherent structure with a combination of wave and vortex is obtained. This explains the mechanism of soil erosion and sand entrainment by the coherent structure of wind gusts.

Keywords:

Lattice Boltzmann Method, large eddy method, wind gust, atmospheric boundary layer

Citation:

Cheng X L, Hu F, Zeng Q C. Simulation of wind gust structure in the atmospheric boundary layer with Lattice Boltzmann Method. Chin Sci Bull, 2012,57: 1196？1203, doi: 10.1007/s11434-011-4950-9