Modeling and simulation of filling in dual-scale fibrous reinforcements: state of the art and new methodology to quantify the sink effect

The main advances in the modeling and simulation of the filling phenomenon that takes place in dual-scale fibrous reinforcements used in liquid composites molding processes are grouped and classified in the present work. Special emphasis is done in the classification of the simulation methods according to the dimension of the mesh, the identification of the interface conditions porous medium-free fluid, the comparison between the most used fluid-front tracking techniques and the survey of researches dealing with the non-uniform filling of representative unitary cells, which in turn is responsible for the void formation at mesoscopic scale and the sink effect at macroscopic scale. As an original contribution to this field of study, a new methodology to quantify the sink effect in macroscopic fillings is presented and subsequently assessed by comparing the results of experimental radial injections with numerical results obtained by the dual reciprocity-boundary element method. The proposed methodology is physically consistent and leads to results that are closer to the experimental ones than the results obtained when the sink effect is neglected; however, the accuracy is liable to be improved.