The interactions between flows occurring inside and outside fabric tows during rtm

An Experimental Assessment of the Saturated Transverse Permeability of Non-crimped New Concept (NC2) Multiaxial Fabrics

“…More especially for composite impregnation the following points are of importance. A newtonian and incompressible fluid is considered [16], this is justified if the infusion (or more generally the impregnation) takes place before the resin gelification. The porous medium is infinitely rigid, this can be questioned for fabrics where compaction may take place during the flow [17].…”

“…Only a more detailed study at the ply level, similar to the one from Backhouse [36] carried out on N CF reinforcements, could bring relevant pieces of answer. To go farther, a multi-scale morphological study has to be considered as demonstrated by Lee and co-workers [10] [14] or Binétruy and co-workers [16].…”

Analytic characterization of the permeability of dual-scale fibrous porous media

“…Although this issue of dual-scale flow behavior has existed for some time and there have been subsequent models that have addressed this issue [2,6,[27][28][29][30][31][32][33][34], only recently have simulations developed capabilities to account for fiber tow saturation separately, in addition to predicting the movement of the macroscopic flow front [17,35,36]. However, such simulations require one to provide a fiber tow permeability value in addition the bulk permeability value for the preform under consideration.…”

Studies on the impregnation of textile semifinished products using a polyurethane spray coat method

“…In principle, there are two different flow types to be distinguished, the intratow (micro) and the intertow (macro) flow. In order to avoid defects caused by air inclusions, the flow inside and outside the yarn needs to be consistent [2,3]. Especially, the influence of micro flow on tow impregnation is highly dependent on capillary forces [4].…”