Novel discretization methods for improved simulation precision in injection molding

Abstract Mold filling is an important stage of injection molding, which is one of the most commonly used manufacturing processes for the production of thermoplastic components in high volumes. As a consequence, the numerical simulation of this process based on computational fluid dynamics (CFD) is of great significance for production engineering [1, 2]. However, modeling of the mold filling is a tremendously demanding process, when considering interfacial physical phenomena, such as two‐phase flows, building a sharp interface between the molten plastics and the present air in the cavity or the dynamic wetting contact line at the cavity surface. A method for dealing with these phenomena is a local mesh refinement both in space and time. In this paper, the numerical solution of a mold filling problem using simplex‐type space‐time finite elements is presented and compared with experiments. These elements can be suited to increase efficiency, when used for the aforementioned refinement. In addition, a Navier's slip boundary condition is applied to the solid boundaries of the mold allowing the contact line to evolve along the boundary, while enabling a better prediction of the pressure distribution. The presented work was performed in collaboration of the subprojects B3 and B5 of the collaborative research center 1120 “Precision Melt Engineering”.