Numerical optimisation of tilt casting process

A coupled mould filling and solidification algorithm based on the Finite Element Method is presented for the tilt casting process. The incompressible, Navier-Stokes equations are solved by the Galerkin finite element method; the metal front is tracked by the pseudo-concentration approach, which is a variant of the volume of fluid method (VOF) and the latent heat release during solidification is taken into account through an effective specific heat. A coincidence-node technique is used to simulate the discontinuity in the temperature field across the metal/mould interface. The tilt casting phenomenon is numerically modelled by keeping the mould stationary and rotating the gravitational force vector. A mathematical expression relating tilting angle to the tilting speed has been proposed so that an optimal value of tilting speed can be predicted by minimising splashing effects. The free surface tracking algorithm is validated against the widely used broken dam problem. The tilt casting results are compared with the experimental results that were available in the literature.