Homogenized free surface flow in porous media for wet‐out processing

Abstract

This paper presents a novel porous media model for homogenized free surface flow, representing wet-out composites processing. The model is derived from concepts of homogenization applied to a compressible two-phase flow, accounting for capillary effects and the concept of relative permeability. Based on mass balance considerations, we obtain a nonlinear set of equations of convection-diffusion type involving the mixture (fluid) pressure and the degree of saturation as primary fields. A staggered Galerkin finite element approach is employed to decouple the solution. Moreover, the streamline upwind/Petrov-Galerkin technique is applied to attenuate the oscillations in the saturation solutions. The model accuracy and convergence of the finite element solutions are demonstrated through 1-dimensional and 2-dimensional examples, representing resin transfer molding flow processes. KEYWORDS free surface flow, partial saturation, porous media theory, process modeling, resin transfer molding Int J Numer Methods Eng. 2018;115:445-461.wileyonlinelibrary.com/journal/nme

A shell model for resin flow and preform deformation in thin-walled composite manufacturing processes

“…Following the developments in [15], we model the wet-out process of the RTM based on the theory of porous media. A two phase porous media is considered, which consists of the solid fiber preform phase and the homogenized resin/gas fluid phase.…”

“…What's more, Remacle et al [14] presented a high-order model using the discontinuous Galerkin method (DGM). Wu and Larsson [15] proposed a homogenized flow model based on the theory of porous media (TPM) to simulate the wet-out RTM process. Another interesting study has been done recently by Dammann and Mahnken [16] who used the phase-field models to model the RTM process.…”

Modeling and Experimental Validation of the VARTM Process for Thin-Walled Preforms

“…where ϕ l := ξn f denotes the liquid volume fraction and ϕ g := (1 − ξ)n f is the air volume fraction. From the homogenization [25], the fluid density is expressed as…”

“…Thus, the fluid pressure, p, and the saturation degree, ξ, are strongly coupled, which makes the problem complicated. The Equations (13) and (14) are solved by using the finite element method as a boundary value and initial value problem developed in [25,46]. Figure 7 shows the staggered approach to decouple the problem.…”

“…Various unsaturated flow models are also reported, e.g., [16][17][18]. Some researchers formulated multiphase flow equations of porous media with the absence of capillary pressure [19,20]; others include the capillary effect, e.g., [21][22][23][24][25][26]. Another approach is to consider the flow as a dual-scale flow.…”