While the volume of fluid (VoF) approach is widely used to simulate mold filling in casting processes, solidification of complex alloys like nodular cast iron, where several phases exist in parallel during solidification, are mostly addressed by an Euler-Euler approach. The later can handle easily several phases, but the description of a sharp filling front is not possible. We used the (VoF)-implementation in STAR-CCM+ in combination with a multi-phase solidification model, based on micro-scale solidification theory, to address both in one approach, mold filling and multi-phase solidification.
A finite-volume method with arbitrary polyhedral control volumes is used to solve flow and solidification strongly coupled. The Volume-of-Fluid approach is used to capture the phase separation between gas, melt and solid in connection with a High-Resolution Interface-Capturing scheme to gain sharp interfaces between phases. Different melt phases are added to this approach, characterized by different composition and material properties, but using the same velocity field. First results for a test geometry are compared to experimental findings.