Instantaneous formation of scalar concentration and ventilation characteristics of an indoor space surrounded by urban-like block arrays using LES

We performed large-eddy simulation (LES) of airflow within an urban building to estimate net escape velocity (NEV) distribution - a velocity scale that describes contaminant transport integrating both convection and diffusion effects, which we superimposed on contaminant concentration distribution. Results showed that at different flow times, contaminant accumulations may appear in local domains of indoor space that were higher than the mean contaminant concentration. These instantaneous accumulations, though happen in short periods, should be infomative in optimized indoor environmental design to avoid cross-contamination.