In this study, a comprehensive continuum dual-scale model has been developed for LCM processes for woven fiber reinforcements. This model incorporates the main flow mechanisms involved, including mass exchange between dual-scale porosities, micro-diffusion within fiber tows between neighboring repeating unit cells (RUCs), and the capillary effect within fiber tows. Macro-and micro-flows are simulated at the same numerical scale. A sink and a source term are introduced into the two different scaled flows to couple them together. An unsaturated flow model is adopted to describe micro-diffusion within fiber tows between neighboring RUCs. The physics of the sink/ source term is modelled according to the impregnation of tows within a RUC. Two models developed in soil physics have been adopted to evaluate the capillary effect and the partially saturated permeability within fiber tows. A finite element method is employed to solve the governing equations, and a simple implicit time integration method is suggested. A 1D RTM example has been modeled. The modeling results indicate that all of the three main mechanisms have significant influences on the LCM processes, but the mass exchange between the dual porosities plays a dominate role, particularly under high injection rates.
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