摘要
The efficiencies of the diffusion deposition of nanoaerosols for a single fiber for the models of aerosol filter and wire mesh screen are studied numerically in the extended range of the Peclet number Pe.The rectangular periodic cell model for fluid flow and convective-diffusive transport of small aerosol particles is used.Most of the previous theoretical and experimental studies of single fiber diffusion deposition efficiency were for the case of Pe>1.The array with uniform square or chess grid of fibers and of a row of circular cylindrical fibers are considered as the filter and wire mesh screen models.The flow and particles transport equations are solved numerically using the Boundary Element Method.The obtained numerical data are used to derive the approximate formulas for the deposition efficiency in the entire range of the Peclet number for the various porosities of the filter medium or distances between fibers in a wire mesh screen.The derived dependencies take into account nonlinearity of the deposition efficiency at the low Peclet numbers.The obtained analytical dependencies compare well with the numerical and experimental data.
