A large eddy simulation method for atmospheric boundary layer inflow turbulence using porous media model

Accurate simulation of incident wind field including mean wind speed and turbulence intensity is one critical aspect for wind load prediction on building through large eddy simulation (LES). Existing methods, including precursor method and synthetic method, both require many rounds of iteration before the target wind field can be simulated, which makes the simulation process hard to be predicted. To make the simulation of incident wind field be more efficient, this paper proposes a novel porous media based turbulence generation (PMTG) method. Three different parts of porous media are arranged in the front of calculation domain to generate the mean wind speed and turbulence intensity profile. Through the detailed analysis between porous media parameters and the generated flow field, the functions of parameters setting for different wind profiles are established. By using the proposed method, it is found that the whole process only requires one to two rounds of iteration to generate the target wind profile. Comparison between the simulated turbulent atmospheric boundary layer with code shows that the proposed method can effectively generate target wind profile with high accuracy. The method is finally used to generate inflow for analyzing the wind load on a low rise buildings. Through the comparison between the simulated results with the wind tunnel experimental data published by Tokyo Polytechnic University (TPU), results show the feasibility of the proposed method on application of wind load evaluation using LES technique. • A novel porous media based turbulence generation method is proposed. • Three different parts of porous media are arranged in the front of calculation domain. • Relation between Porous media parameters and wind profile are established. • Only 1 or 2 rounds of iteration are needed to generate the target wind profile。