Permeability modeling of fibrous media in composite processing

The manufacturing of composites among industrial products involves the impregnation of fluid resins through fibrous reinforcement. In the modeling of resin transfer molding process in particular, an accurate description of resin flow through the fibrous media is required. In this study the permeability, which plays an important role in describing the resin flow through fibrous media macroscopically, is first computed for the microscopic flows through fiber packing structures such as square and hexagonal packings using the finite element simulations. A model, referred to as coupled flow model, is then proposed in order to obtain an accurate estimation of the permeability through real fibrous media composed of the fiber bundles, considering macroflow within a fiber bundle and macroflow around bundles simultaneously. The results obtained from the coupled flow model are in better agreement than the previous models with currently available experimental data, and this model could be put into practical use in obtaining a more quantitative estimation of the permeability of fibrous media.