Permeability prediction for industrial preforms

Abstract

This paper presents an overview of a method of predicting the permeability of textile preforms. The equations involved in the calculation of the pressure distribution and flow field resulting from the imposition of a pressure gradient between two opposed faces of a porous domain are outlined. The presentation is for a two-dimensional cross-section but the method applies to a full three-dimensional domain featuring porous tows and free channels defined between the tows. The mathematical treatment was kept as simple as possible in order to gain speed and improve productivity. Fast calculation methods allow the prediction of the variation of permeability over a preform, providing valuable information to the simulation of the filling. The method does take into account the heterogeneity of the preform, the architecture of the textiles, as well as the porosity and shape of the tows.