Analysis of fluid permeability in tortuous fibrous bed based on pore radius distribution

The effect of fiber tortuosity on fluid permeability in fibrous beds has been investigated. A particle model is employed in which a fiber is replaced by spherical particles and fiber tortuosity is represented by a bending angle. Assuming a low Reynolds number, the fluid permeability is calculated based on the Stokesian dynamics approach. The results show that the permeability of a tortuous fibrous bed is lower than that of a straight fibrous bed. To examine the permeability dependence on the fiber tortuosity in detail, the pore distribution and pore connectivity are evaluated quantitatively by defining the pore radius. It is found that the tortuous fibers prevent the formation of large pores and their connection in the flow direction, thereby decreasing the permeability. Graphic abstract