The problem solved here is illustrated in Figure 4.1: Problem Description. The fluid enters the domain at a flow rate of 10 cm3/s, and the screw rotates at an angular velocity of 2π rad/s. In the upper part of the domain, a free surface is used to model the extrudate going out of the extrusion die; the position of the free surface is unknown. A portion of the mesh will be affected by this unknown boundary, so a remeshing technique will be applied on this part of the mesh.
