Large eddy simulation of the turbulent boundary layer behind roughness elements using an artificially generated inflow

Abstract A turbulent boundary layer at high Reynolds number generated by a rough surface was calculated by large eddy simulation (hereafter abbreviated as LES). The inflow wind fluctuations conditioned by the experimental data were generated artificially. The velocities at the inlet boundary were interpolated in Fourier space as stochastic processes in a conditional random field so as to realize the equivalent statistical quantities of experimental results. The calculated turbulent field just behind the roughness elements was compared with the experimental data and examined. The calculated result shows rather good agreement regarding the mean wind field and the turbulent energy spectra in the low frequency. Otherwise the energy of the high-frequency wind fluctuation decreased and the wind fluctuations were less correlated in the calculated results.