Simulation studies of deposition mechanisms for aerosol particles in fibrous filters including slip flow

A geometric model for the 3 dimensional structure of nonwoven was developed. It contains the porosity, fiber diameters and fiber anisotropy as parameters, and results in large three-dimensional discretized realizations of the media. In these structures, the fluid flow and particle deposition are simulated. Initial pressure drop, filter efficiency and filter lifetime are quantities that are computed based on the nonwoven, the mean flow velocity and the particle size distribution. Here the focus is on isolating the effects of different deposition mechanisms, fiber diameter, solid volume fraction and flow regime on the filter efficiency and establishing qualitative agreement with analytic formulas as well as measurements.