Numerical flow front tracking for aluminium extrusion of a tube and a comparison with experiments

The first stages of the extrusion process can lead to extraordinary deformations of the extrusion dies. Especially in porthole dies the location of the mandrel can shift due to deformation of the die. This paper focuses on the problems related to the simulation of the filling of porthole dies during this start-up of the process. To avoid expensive remeshing during an Updated Lagrangian simulation an Eulerian description is used. This is time efficient however it gives challenges with respect to the tracking of the flow front. During the filling a function that keeps track of the flow front has to be convected through the mesh [5]. In this paper we show that by using the smooth original coordinate function the convection can be done accurately. The result is that during the simulations the volume is conserved properly. The simulated flow fronts are compared to experimental results. In a previous paper [3] we have shown the accuracy of the original coordinate function, in 2D simulations. In this paper the extension to 3D is made adding a comparison with experiments.