A comparative study of synthetic turbulence inflow approaches for air pollution simulation

Accurately modeling the turbulence characteristics of wind flow entering urban areas is essential for improving the reliability of air pollution simulations, particularly when utilizing the LES approach. In this study, the Consistent Discrete Random Flow Generation method was implemented within the OpenFOAM software and evaluated for the first time in the context of solving concentration equation. A comparison of four inlet boundary conditions was conducted using wind tunnel experimental data. It was found that CDRFG presents more accurate results than the other methods, with an average error of 18 %. Then, the performance of the method in a complex geometry was evaluated by comparison with both experimental data and field measurements. The simulation demonstrated a high degree of accuracy in predicting the average dimensionless concentration, showing a close match with the experimental results, with a mean error of 16 %, and with the field measurements, exhibiting a mean error of 37 %.