title: Deposition of fractal-like aerosol aggregates in a model of human nasal cavity.
abstract: Toxicity of diesel exhaust is related to the inhalation of nano-sized fractal-like aerosol aggregates. Their complex behavior (in comparison to spherical particles) should be taken into account in deposition modeling. The deposition of aerosol fractal-like aggregates in the model of a human nose was studied numerically for the flow rate corresponding to breathing conditions. The simplified geometry of the human nasal replica was implemented in the computational fluid dynamics (CFD) code (FLUENT) used for calculation of the three-dimensional airflow structure. A Brownian dynamic (BD) algorithm was applied for determination of the aggregates deposition in the nasal cavity during inhalation. These calculations were carried out for several populations of aggregates. The values of parameters used in the BD simulations for characterization of fractal-like aggregates, that is, fractal dimension (Df) and the radius of gyration (Rg), were in the range of 1.7-2.1 and 0.24-0.36 microm, respectively. These are the representative values for soot aggregates emitted from diesel engines. The results of computation show approximately 20% penetration of submicrometer aggregates through the nose and a weak dependence of deposition efficiency on Df and Rg values. The proposed methodology may lead to a more realistic description of deposition of nonspherical aerosol particles in the respiratory system. A more sophisticated approach for description of fractal-like aggregates dynamics is suggested for future studies.
authors.affiliation: Department of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland. moskal@ichip.pw.edu.pl
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Moskal
authors.forename: Lukasz
authors.initials: L
authors.lastname: Makowski
authors.forename: Tomasz R
authors.initials: TR
authors.lastname: Sosnowski
authors.forename: Leon
authors.initials: L
authors.lastname: Gradoń
mesh_terms: D000336:Aerosols / Q000737:chemistry* / Q000633:toxicity; D000465:Algorithms; D017709:Fractals; D006801:Humans; D008953:Models, Anatomic; D008956:Models, Chemical; D053758:Nanoparticles; D009296:Nasal Cavity / Q000033:anatomy & histology*; D015656:Respiratory Mechanics; D001335:Vehicle Emissions / Q000633:toxicity
chemical_list: D000336:Aerosols; D001335:Vehicle Emissions