Three-Dimensional Design-Oriented Simulation of PAC Torches

Three-dimensional phenomena, related to the fluid dynamic behavior of the plasma and secondary gas in the region between the torch tip and the workpiece, have been studied by means of a 3-D FLUENT-based numerical model, with the final aim of optimizing the design of a prototype monogas plasma arc cutting torch, operating in the range 25-100 A. The details of the spacer for contact cutting geometry and of the metallic substrate with the keyhole are included in the computational domain. The development of a 3-D model was necessary to solve specific design issues that cannot be properly studied by 2-D models, providing also useful results to be compared with experimental evidences coming from diagnostic and cut quality/erosion tests.