Numerical modeling of three-dimensional flow in filter media

The airflow in a filter has been modeled by considering the three-dimensional nature of the fiber arrangement in the media. The classical assumption of an uniform two-dimensional fiber distribution is seen to result in an inaccurate expression for the fiber drag. The three-dimensionality of the filter structure is seen to result in a reduced fiber drag for a given packing density, which agrees well with the experimental observations of pressure drop. Consideration of real filter properties like inter-fiber distance and packing density distribution result in a more realistic estimation of fiber drag and the results of the numerical simulation considering the real properties of the media are compared with the experimental observations.