Finite element analysis of GTAW arc under different shielding gases

The aim of this work is to use COMSOL software as a tool for solving the 2-D Magnetohydrodynamics (MHD) problem in the Gas Tungsten Arc Welding (GTAW) arc under the shielding gases argon, helium, nitrogen and argon + 10% hydrogen. COMSOL 3.5a worked perfectly for solving multiphysics phenomena, including the Navier-Stokes flow equation, the heat transfer equation and the Maxwell Equation. COMSOL software can be utilized to simulate the temperature and velocity profile in the GTAW arc after some validation procedures. Cumbersome experimental work can be avoided by using this numerical instrument. For our study, we compared the numerically calculated temperature profile and maximum plasma velocity under argon shielding gas and maximum temperature of a nitrogen arc with experimental results found in the literature. We also compared the numerically calculated velocity profile with another numerical solution found in the literature. Our comparisons showed good agreement. The highest temperature was in the nitrogen arc, while the highest voltage was in the helium arc. The highest total energy was in the helium arc similar to the voltage value. The highest plasma velocity values were obtained in the nitrogen and helium arcs. The most constricted arc was calculated in the nitrogen arc. (C) 2011 Elsevier B.V. All rights reserved.