A simplified in-plane permeability model for textile fabrics

In this paper. a simplified in-plane permeability model for textile fabrics is developed. The model is based on a rectangular unit cell geometry, the one-dimensional Stokes equation for now in the channels or gaps between fib er tows, and the one-dimensional Brinkman equation for flow in fiber tows. Three different textile fabrics are considered in the model: plain woven, 4 -harness, and bidirectional stitched fiberglass mats. The model incorporate s the effect of porosity changes on permeability of fiber preforms under co mpression, which usually occurs in the molding process. To verify the valid ity of the model, the theoretical values are compared with a set of permeab ility measurements. Good agreement is found between the model prediction an d the permeability measurements in the porosity ranges of phi less than or equal to 0.59 for plain woven fiber mats, phi less than or equal to 0.60 fo r 4-harness fiber mats and phi less than or equal to 0.62 for bidirectional stitched fiber mats.