Results of a simulation of the Self Reacting Friction Stir Welding (or bobbin tool) process. When simulation meets beauty... Those pictures show an Eulerian simulation handled by GeonX using Virfac®. The stream lines indicate the material flow in the weld zone. Virfac® gives a precise idea of the energy dissipated in the material, which helps characterize the energy density injected into the material around the tool.