The dispersion of air pollution around buildings is complicated to model. The building effects module in ADMS-Screen is the same as that in ADMS except it only models one building instead of many. It includes the following features.
One building can be included in each model run. For each wind direction, a single effective wind-aligned building is defined, around which the flow is modelled.
The flow field consists of a recirculating region (or cavity), with a diminishing turbulent wake downstream.
Concentrations within the cavity, CR, are uniform, and based on the fraction of the release that is entrained. The concentration at a point further downwind is the sum of contributions from two plumes: a ground-based plume from the recirculating flow region and an elevated plume from the non-entrained remainder. The concentration and deposition are set to zero within the user-defined building.