Diffusion processes experimental analysis of atmospheric gaseous pollutants in a wind tunnel

Abstract

The objective of this work is the study of atmospheric pollutants dispersion problems in wind tunnels. The use of a reduced scale model provides the ability to analyze the process of dispersion in complex models. It also allows the study of different situations and alternatives in the source design. The wind tunnel pollutants dispersion simulation requires two sets of similarity criteria; the first established that the wind tunnel flow must be similar to natural wind in the atmospheric boundary layer, and the second, that the model source characteristics must be similar to prototype. In this work, the similarity criteria of the atmospheric flow and the emission source are studied to reproduce dispersion processes and develop a first approach to the experimental study of this phenomenon. Firstly, the results of a visualization dispersion process test performed at the wind tunnel of the Facultad de Ingeniería de la Universidad Nacional del Nordeste, using smoke as a tracer and considering three operation velocities are presented. The study of the plume evolution was made by image digital processing and the plume rise is also discussed by comparison of measurements with theoretical values. Finally, preliminary experiments results are presented to evaluate concentration field from an isolated point emission source using a light gas and reduced scale model.

Keywords: atmospheric dispersion, similarity, wind tunnel.