Numerical Investigation of Flow in Fibrous Porous Media

Fibrous porous materials involve in many natural and engineering processes. In this study, the permeability of ordered fibrous media towards normal and parallel flows is studied numerically. Porous material is represented by a “unit cell” which is assumed to be repeated throughout the media and 1D fibers are modeled as a combination of Channel-like conduits. The numerical results are successfully compared with the experimental data collected by others and existing correlations in the pertinent literature, for square arrangement of fibers over a wide range of porosity. A compact correlation is proposed for parallel permeability of fibrous media, which can predict the results accurately over the entire range of porosity. Moreover, microscopic velocity profiles in the unit cell are investigated in detail for both parallel and normal flows. The numerically predicted velocity distributions for normal and parallel flow cases are compared with experimental and simple parabolic profiles. The comparison showed that although assumption of the parabolic velocity distribution results in reasonable values for permeability, this form of the velocity profile is not realistic.