Simulation of Plasma and Shielding Gas Flows in （模拟等离子体和保护气体流动）.pdfVIP

International Scientific Colloquium Modelling for Material Processing Riga, June 8-9, 2006 Simulation of Plasma and Shielding Gas Flows in Welding and Cutting Arcs with Ansys CFX Michael Schnick, Uwe Füssel, Jörg Zschetzsche Abstract The electric arc is widely-used for welding and cutting of metals. The knowledge of the plasma and shielding gas flow as well as its interaction with the electric arc and the energy transport in the workpiece is essential for optimizing torches and the welding and cutting process. For the simulation of electric arcs the commercial computational fluid dynamics code Ansys CFX can be used. Additionally a MHD model for calculation of the electromagnetic effects and large datasets of the plasma gas properties have to be implemented. By explaining the solution of a simulated hand-guided torch for plasma-welding the influence of process parameters, shielding gas properties and nozzle design is presented. 1. Introduction Plasma jet and arc processes are widely used for cutting, welding and coating of metals. The shielding gases as well as their flow profiles near the arc have a decisive influence on the machining results [1] [2]. Examples are the dependence of plasma welding processes on the plasma gas mass flow and the nozzle diameter, porosities in the seam of shield gas welding caused by the introduction of air after damaging the gas shield, the critical influence of particle movement in gas flows on the results of flame and plasma coating, and the improvement of kerf quality by optimizing the plasma and swirl