Andrew Jay Salem

The interaction between micro- and macro-scopic flow in RTM preforms

Abstract Both experimental and modeling results are presented to convey the wide span of length scales over which flow in porous media can occur in a single material. Flow in such heterogeneous porous media are shown to be important in composites processing because the structure of fibrous reinforcements contains multiple length scales. Flow phenomena that arise due to material heterogeneity have been shown to include void formation and to explain the differences observed between measurements of the ‘wet’ permeability and the ‘dry’ permeability. The work presented indicates that the heterogeneous reinforcement structure may also contribute to the differences observed in permeability measurements carried out by the radial flow and the one-dimensional flow methods. The concept of heterogeneous porous media is also extended to the molecular level by considering the flow problem in a reinforcement sized with grafted macromolecules.