OpenFOAM large-eddy simulations of atmospheric boundary layer turbulence
Liang Shi, DongHun Yeo
Reproducing the turbulence statistics of atmospheric boundary layer (ABL) flow in a computer remains a challenge. In this paper, we perform large-eddy simulations of neutrally stratified ABL flow using the open-source toolbox OpenFOAM and examine the statistical properties. An one-equation eddy model is employed 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 due to the limited accuracy of the SGS model. The second and third moments of the turbulence represent well the underlying physics. The SGS dissipation agrees with the proposed theoretical model. The spatial spectra follow well the -5/3 power law at large wavenumbers. The spectra of the velocity components at a single point consist with the modified Kaimal expressions. The spatial coherences decay exponentially as functions of reduced frequncies. The results suggest that, except for the mean velocity near the ground, the turbulence statistics of ABL flow can be well represented by large-eddy simulations using simple SGS and wall models.