A finite element/control volume approach to mold filling in anisotropic porous media

TLDR

Mold filling in anisotropic porous media governs composite manufacturing processes such as resin transfer molding and structural reaction injection molding. The paper presents a numerical simulation to predict viscous fluid flow through a fiber network. The simulation employs a finite element/control volume method with Darcy’s law, allowing anisotropic, spatially varying permeabilities measured from experiments on fiber preforms. The model accurately predicts the free‑surface flow front in arbitrary thin‑shell molds and agrees with experimental data from flat rectangular molds across various preforms and processing conditions.

Abstract

Abstract Mold filling in anisotropic porous media is the governing phenomena in a number of composite manufacturing processes, such as resin transfer molding (RTM) and structural reaction injection molding (SRIM). In this paper we present a numerical simulation to predict the flow of a viscous fluid through a fiber network. The simulation is based on the finite element/control volume method. It can predict the movement of a free surface flow front in a thin shell mold geometry of arbitrary shape and with varying thickness. The flow through the fiber network is modeled using Darcy's law. Different permeabilities may be specified in the principal directions of the preform. The simulation permits the permeabilities to vary in magnitude and direction throughout the medium. Experiments were carried out to measure the characteristic permeabilities of fiber preforms. The results of the simulation are compared with experiments performed in a flat rectangular mold using a Newtonian fluid. A variety of preforms and processing conditions were used to verify the numerical model.