EXPERIMENTAL AND ANALYTICAL STUDY ON THE PARTICULATE ENTRAINMENT AND DISPERSION FROM A POROUS EMISSION SOURCE IN WIND

General particulate entrainment mechanisms and dispersion of entrained particulates from a porous emission source in wind such as storage pile are studied. The mechanisms of particulate entrainment and downwind particulate dispersion are experimentally determined with the use of two porous pile models of different heights: a 51 mm high model and a 76 mm high model. The reduction of blowing velocity on the surface of the source is illustrated by the proper use of the windbreaks located at approximately two to three pile heights upstream. The tracers used in the experiment are smoke, magnesia, latex, and glass particles. The scaling results based on the measured data indicate that the effect of particle settling due to gravity force will be significant when the particle settling velocity is greater than 0.03 m/s.;Study shows a useful wind barrier location will be two to three pile heights upwind of the pile. Particle sizes studied range from 15 m to 75 m. Particles less than 15 m will likely remain in suspension over long distances. A successful computer modeling of non-point source dispersion has been presented.;The principles of multiphase fluid dynamics are used to compute the dispersion of entrained particulates from finite area sources. The finite differences technique is used for two-dimensional and three-dimensional steady state simulation of particulate dispersion; while the case of transient dispersion is solved analytically. The effects of the particle sizes, the height of the emission source, wind velocity, and the ground conditions on the downwind particle density distribution are presented. The effects of lateral and vertical particle diffusivities variation with height are particularly treated. Results indicate that at locations near the source or if the wind velocity is low, two-dimensional steady state approximation is applicable. However, if the location is far away from the source and the wind velocity is high, the three-dimensional transient approximation shall be used instead.