CFD prediction of gaseous diffusion around a cubic model using a dynamic mixed SGS model based on composite grid technique

Turbulent diffusion of gaseous contaminant near a cubic-shaped building model is predicted by LES using a Dynamic Mixed SGS (DM) model with the aid of the composite grid technique. The results obtained using a composite grid show better agreement with experiment than does the case using a single grid. Some discrepancies from the experimental results are observed in the results of the standard Smagorinsky model with a composite grid. These discrepancies are improved remarkably by using the DM model.