The Effect of Certain Morphological Features on the Permeability of Clustered Fibrous Media

Abstract

A good understanding of the microscopic details of flow through fiber preforms remains a critical step in the design and optimization of composite liquid molding processes such as Resin Transfer Molding (RTM) and its variants. However, the measurement of the key relevant property, namely the permeability of the preform, is still not standardized and remains difficult to perform as well as to interpret. In this paper, numerical results are presented for boundary element simulations of creeping flow through model fibrous media made up of parallel fiber bundles. Starting from ordered arrays of fiber bundles, several types of microstructural variations are introduced, and their effect on permeability is examined and quantified. It is shown that deviations from regular arrays cause substantial scatter in the corresponding permeability values. These results help to understand the large data scatter typically observed in permeability measurements.