A FEM model for the calculation of heat and fluid flows in DC casting of aluminum slabs

A 3D FEM model for the solution of time dependent incompressible flows with solidification and natural convection is presented. In the mush zone the momentum equations are modified with a Darcy type source term dependent on the liquid fraction. The numerical method applies a fractional step method for the dynamic Navier Stokes equations and the Streamline Upwind Petrov-Galerkin (SUPG) method for mixed diffusion and convection in the momentum and energy equations. The model is used to simulate the stationary period during DC-casting of a full size commercial rolling ingot, with a nozzle/filterbag distributor system. Comparisons with measured temperatures in liquid aluminum during casting are made, as well as with DAS measurements. Influence of natural convection turbulence by the LRN {kappa}-{var_epsilon} model and permeability of the mushy zone are studied.