APPLICATION OF WIND TUNNEL FOR MODELLING POLLUTION DISPERSION IN THE NEUTRAL ATMOSPHERIC BOUNDARY LAYER

Wind tunnel was employed to simulate the pollution dispersion in the neutral atmospheric boundary layer flow. The test section of the wind tunnel had a cross section of 2 m by 1.4 similar to 1.6 m, and was 12.6 m in length. The tunnel was an open suction type and it contracted to the test section with an area ratio of 4:1. The turbulence intensity of the empty tunnel is less than 0.5 % at the mean velocity of 5 m/s. Similitude law of fluid mechanics was applied to study physical model experiment of pollution dispersion in wind tunnel. Hot wire anemometry was used to measure the turbulent flow. Release of tracer in the wind tunnel was to simulate the pollution dispersion. Tracer concentration was measured by Flame Ionization Detector. Selected illustrative example of investigation such as: (1) flow and dispersion of pollution in the hilly terrain, (2) dispersion of pollution in the urban built in environment, (3) pollution dispersion around three prismatic buildings, (4) heavy gas dispersion around hill and building, was presented. In summary, the environmental wind tuunel is a feasible and useful tool which can be excuted the physical model simulation on the flow and dispersion of pollution.