Pore-scale modeling of wettability effects on infiltration behavior in liquid composite molding

The effect of wettability on the infiltration behavior in the liquid composite molding process has not been fully studied, and the available evidence appears to be conflicting. Based on the three-dimensional microcomputed tomography images of porous media, a series of immiscible displacement simulations under a wide range of wettability conditions was established by the phase field method. Interestingly, we found that increasing the affinity of the porous matrix for the invading fluid can increase the displacement efficiency and reduce the void content until the critical wetting transition is reached, beyond which the displacement efficiency decreases sharply. The nonmonotonic behavior of the wettability effect can be explained by the competition among complex and intriguing pore-scale displacement events, mainly involving the Haines jump, cooperative pore filling, and corner flow. These novel findings provide a theoretical basis for extracting the optimal wettability range, thus minimizing the void content formed during the liquid infiltration process.