Numerical and wind-tunnel simulations of flow and dispersion around a building

Flow and dispersion of gases released by sources located on its roof was simulated using k-ε (RNG) and the large eddy simulation (LES) turbulence model in different wind direction, with numerical results were compared with wind-tunnel data. The result of flow shows that, numerical simulation can better simulate the top backflow of the building and the rear cavity zones, etc. The result of concentration shows that, numerical simulation result is in good agreement with that from wind tunnel experiment in the windward side and the top backflow zones of the building. However, numerical simulation result is slightly higher than from wind tunnel experiment in the rear cavity zones. As a whole, compared with wind tunnel experiment, LES model can better simulate the variation of pollutant' concentration field and flow field around the buildings. (authors)