Permeability Predictions for Woven Fabric Preforms

Abstract

A model is proposed to predict woven fabric permeability. The dual-scale fabric preform is represented by a unit cell of heterogeneous porous medium consisting of equivalent intertow and intratow porous media. The Stokes equation is used to model the flow in the intertow region of the unit cell, and the permeability of the equivalent intertow porous medium is calculated by back substituting the resultant pressure and velocity fields into Darcy’s law. With knowledge of the permeabilities of the two equivalent porous phases, the permeability of the unit cell for the fabric preform can be easily determined by solving the Darcy flow in the equivalent heterogeneous porous medium. The effects of geometrical parameters on the permeability of plain-weave fabric preforms are investigated. It is shown that, as well as the fiber volume fraction; other geometrical parameters such as the gap between adjacent tows also play an important role in determining permeability. Permeability predictions for three plain-weave fabrics show satisfactory agreement with experimental data available in the literature.