Extrusion is one of the most common applications for Ansys Polyflow. Information about the free surfaces and moving interfaces that are involved in extrusion problems is presented in this chapter, along with information about the remeshing techniques that can be used for the changes to the mesh that occur during extrusion and related processes. See also Blow Molding and Thermoforming for information about free surface problems that include contact detection.

Note that Arbitrary Lagrangian-Eulerian (ALE) approach described in this chapter is a combined formulation; this is in contrast to the strictly Eulerian formulation used in the volume of fluid (VOF) model, which is the other means of simulating a free surface in Ansys Polyflow. See Introduction for a comparison of the two methods.