Prediction of Gas Permeability of Multilayer Woven Reinforcements for SiC _f /SiC Porous Composites

The permeability is a key property of SiC _f /SiC porous composites using as filter in high temperature. In this study, an analytical model based on Hagen–Poiseuille flow was used to investigate the relationship between the structural properties and the filtration performance of the fiber architecture, including fabric and stitched preform. The air flow through the fabric was considered in two different regions: inter-yarn and inter-fiber, as well as the pore properties of the fabrics. The key feature of the model was that the parameter of flow channel based on the pore shape was taken account into the calculation of the equivalent pore size. After determining the pore characteristics, the flow rates of the pore unit cell were obtained; subsequently, permeability of the fabrics and stitched preforms were predicted to compare with the experimental ones. This turns out that the analytical model shows a good correlation between the experimental and predicted permeability values, and the difference between different woven-type fabrics was well presented.