Numerical study of multi-dimensional multi-phase flow in the vacuum assisted resin infusion

Vacuum Assisted Resin Infusion (VARI) has been widely used in manufacturing large-size structures. However, the multi-dimensional flow nearby inlets may cause serious defects in the parts due to unreasonable arrangement of the tooling materials. Also, the air entrainment in the infusing resin affects the process quality. In this paper, a 3-D flow field was simulated by considering the omega flow line, resin distribution mesh, caul plate, porous membrane, peel ply and the preform. The resin system in the flow field was treated as a mixture with three phases: resin, air trapped in resin and residual air in preform. The extra resin distribution mesh between the omega flow line and caul plate was proved to result in a negative effect on the entirely infiltration of resin near inlets. Using the materials with lower permeability could improve the defects around the omega flow line. The higher permeability of the release fabrics and porous membranes might be helpful to accelerate the resin infusion, but it was harmful to improve the qualities of final parts. Using the release materials with lower permeability and deserting the irrational resin distribution mesh simultaneously could lead to the defect-free parts.