Simulation of aerosol filters at intermediate Knudsen numbersстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 21 декабря 2017 г.
Местоположение издательства:Road Town, United Kingdom
Первая страница:492
Последняя страница:504
Аннотация:Gas flow and the deposition of submicron particles on a model filter (in a system of fibers perpendicular to the flow) were studied at low Reynolds numbers and intermediate Knudsen (Kn) numbers, The cell model and the BGK model of the kinetic theory of gases were employed to determine the flow field. The instantaneous picture of the gas velocity and density distributions during the movement of a fiber placed into the cell center is assumed to be stationary; the surfaces of cell and fiber are considered to be impenetrable for gas molecules. The Maxwell boundary conditions on a fiber and the Kuwabara conditions at the cell boundary are employed. The fields of gas velocity and pressure are determined from the solution of the kinetic equation for the distribution function of gas molecule velocities. It was shown that the dependence of the reciprocal dimensionless force acting upon a unit fiber length on the Knudsen number is approximated by a line coinciding with the extrapolation solution for a viscous regime with slip (Kn much less than 1). The dependence obtained corresponds to the experimental data for model fibrous filters at Kn similar to 1. Accounting for the incomplete accommodation of molecules does not affect the linear pattern of this dependence. It was also demonstrated that accounting for the profile of gas flow velocity in the Knudsen layer results in a noticeable decrease in the collection efficiency of single fibers under the diffusion mechanism of deposition as compared to the efficiency calculated by the known formulas for the regime of viscous flow including the gas slip and slightly affects the efficiency due to interception.