Simulation of aerosol fibrous filters at Reynolds numbers of the order of unity

Abstract

The deposition of aerosol particles from a flow in a model filter composed of parallel rows of parallel fibers oriented normal to the flow direction has been studied at Reynolds numbers of the order of unity, Re ∼ 1, which are inherent in analytical filtration. The Oseen flow field in a row has been determined by the method of fundamental solutions. It has been shown that the drag forces of the fibers to the flow and the efficiencies of inertial particle collection on the fibers calculated based on the obtained field insubstantially differ from those calculated by the Navier-Stokes equations. The higher the filter packing density, the larger the Re numbers at which the drag forces begin to differ. In the case of inertial particle deposition, the difference between the collection efficiencies increases with the interception parameter. For rows with a/h > 0.2 (a is the fiber radius, and 2h is the interfiber distance in a row), including rows with a nonuniform arrangement of fibers, the calculations performed by both the linearized and complete Navier-Stokes equations yield almost equal results up to Re ∼ 1.