Computer Modeling of Aerosol Filtration by Fibrous Filters

Abstract

An inline array of parallel circular cylinders, placed transverse to the flow, is used as a model for fibrous filters. The flow field within the array is obtained by solving the full Navier—Stokes equations with the assumption of periodic, fully developed flow. A control volume differencing scheme is used for this purpose. The flow field can be computed for both the viscous and laminar flow regimes. Predictions of pressure drop and particle collection due to interception and diffusion have been obtained using the inline array model, for packing densities varying from 0.029 to 0.136. The collection efficiency for deposition due to interception is directly calculated from the computed flow field. The deposition or particles due to diffusion is studied by numerically solving a separate transport equation for particle concentration, without making any boundary layer approximations. The results have been compared with the data from previous studies, both theoretical and experimental. It is shown that the results obtained from the inline model, in most cases, compare favorably with those obtained from previous studies.