Implementation of a three-dimensional numerical model for the filling process in Liquid Composite Molding on polyhedral meshes

In this paper, a three-dimensional, two-phase numerical model based on polyhedral meshes was developed to simulate the resin-filling process in Liquid Composite Molding (LCM). The Algebraic Volume of Fluid (VOF) method tracked the resin flow and the finite volume method (FVM) was applied for stable numerical discretization and solution. The numerical model was validated by unidirectional flow experiments, with the maximum error observed at the flow front being within 5.00 %. Subsequently, the performance of polyhedral meshes in LCM simulations was compared with that of hexahedral and tetrahedral meshes, following the mesh-independence analysis. The results show that the accuracy of the model using polyhedral cells is close to hexahedral cells and higher than tetrahedral cells. The cell number of polyhedral cases is about half that of hexahedral cases and a quarter to a third of tetrahedral cases, assuming similar computational accuracy and mesh size. Polyhedral meshes consume the least computational resources, slightly less than hexahedral meshes and approximately one-third of tetrahedral meshes. Furthermore, polyhedral meshes have a similar level of mesh generation to that of the tetrahedra and are better adapted to complex geometries. Numerical modeling utilizing polyhedral meshes is advantageous for large-scale and complex-shaped parts.