Transport, Deposition and Removal of Fine Particles - Biomedical Applications

Abstract

In many biomedical, environmental, and industrial applications, small particle transport, deposition, and resuspension play a critical role. Pollutant transport and deposition in the respiratory passages, cardiovascular flows, pollutant transport in buildings and in cities, fluidized bed combustors, and fuel spray in internal combustion engines are but a few examples. Understanding motions of small particles suspended in a gas or liquid has received considerable attention in the past few decades due to its significance in numerous scientific and industrial applications. Natural and man-made aerosols and colloids consist of a variety of solid and liquid particles suspended in a gas or liquid. Understanding the kinetics of particle dispersion and deposition in different passages has attracted considerable attention due to its importance in numerous industrial processes.63 Reviews of the earlier experimental and modeling works on aerosols and particle transport and deposition processes were provided by Levich,171 Fuchs,109 Mercer,198 Twomey,267 Hinds,134 Spurny,250 Seinfeld,241 and Vincent,269 among others. Extensive reviews of turbulent diffusion were provided by Levich171 and Hinze.135 Tchen260 was the first investigator who modified the Basset-Boussinesq-Oseen (BBO) equation and applied it to study motions of small particles in a turbulent flow. Corrsin and Lumley65 pointed out some inconsistencies of Tchen’s modifications. Csanady69 showed that the inertia effect on particle dispersion in the atmosphere is negligible, but the crossing trajectory effect is appreciable. Ahmadi1 and Ahmadi and Goldschmidt2 studied the effect of the Basset term on the particle diffusivity. Maxey and Riley187 obtained a corrected version of the BBO equation, which includes the Faxen102 correction for unsteady spatially varying Stokes flows. Experimental studies of diffusion and dispersion of particles in turbulent flows were carried out by a number of researchers. A detailed experimental study on turbulent diffusivity was reported by Snyder and Lumley.246 Calabrese and Middleman33 and, Arnason12 measured the dispersion of particles in a fully developed turbulent