Large eddy simulation of spanwise contaminate dispersion in the wake region of an isolated building by dynamic subgrid scale Schmidt modeling

In this paper the effects of subgrid Schmidt number, ScSGS, on the flow and dispersion around a cubical model building with a flush stack located on the roof is examined by using the LES approach. For this purpose, dynamic kinetic energy subgrid scale model with dynamic approach for ScSGS modeling in the linear eddy diffusivity model for representing the subgrid scale diffusion X[ (6*6 )) are employed. It is concluded that dynamic procedure is acceptable in turbulence modeling of contaminate dispersion(K) by LES approach. However, on the centerline of leeward wall and in the wake region all models over predict the values of contaminate dispersion. Generally both ScSGS procedures overestimate the time-averaged concentration in streamwise direction near the wake region however in the vertical direction distribution of K is acceptable. Moreover, calculated ScSGS in wake region of an isolated building as predicted by the dynamic procedure seems to be acceptable in turbulence modeling of contaminate dispersion prediction by LES approach.×

Keywords:

LES , dynamic subgrid scale Schmidt modeling , atmospheric boundary layer , CFD