As previously demonstrated, the simulation of turbulent flow during the thermal pouring stage (involving crucible discharge and mould-filling) in conjunction with solid-liquid phase change phenomena is deemed computationally expensive. Therefore, in this chapter, specific process assumptions are employed to simplify the complexity of the problem at hand, aiming to avoid the simulation of the pouring stage and markedly reduce the computational demands. Nevertheless, in this study, the following key assumptions are made: Firstly, the casting mould and the sand-plug are not physically considered in the simulations, instead, they are implemented as an adiabatic boundary condition.