Two-dimensional simulations of resin flow in dual-scale fibrous porous medium under constant pressure

Abstract

In liquid composite molding (LCM), the resin is filled into the stationary fiber to impregnate all the empty space. Because the use of fiber features the double-scale porous property, partially saturated region phenomenon will occur during the process of resin flow. Therefore, a non-zero sink-function appears on the right side of the equation of mass conservation in fluid dynamics. In this paper, the control volume/finite element method is applied to simulate the flowing characteristics of resin in two-dimensional mold under constant pressure. A corresponding algorithm is designed, and a two-dimensional program for finite element algorithm based on both dual-scale and single-scale is compiled. Compared with the flowing characteristics of resin in single-scale fibrous porous medium under the same conditions, it can be concluded that there is an unsaturated flow front in the resin flowing of the dual-scale fibrous porous medium according to the unsaturated region. The pressure distribution and filling time make huge difference when they reach the same flow front. Changing the initial pressure of resin in dual-scale fibrous porous medium will greatly affect the distribution of pressure and fill time.