Simulation of Pollution Dispersion Using Small Scale Physical Models - an Assessment of Scaling Options

This paper concerns the role and nature of physical modelling as applied to dispersion studies. The arguments leading to the choice of model scale are discussed. The simulation of atmospheric flows and emissions are described, in particular the similarity conditions linking full scale and model conditions and their implications in terms of facility size and performance. We briefly summarise typical experimental programmes and treat the issues involved in interpreting results. Then we present three examples of laboratory studies. The first illustrates the ability to perform a simple plume rise simulation and the other two demonstrate building affected dispersion simulations. The final discussion centres on applications of physical modelling to urban air quality investigations.