Numerical analysis of the arc in pulsed current gas tungsten arc welding using a boundary-fitted coordinate

A two-dimensional transient model is introduced to describe the heat transfer and fluid flow in pulsed current gas tungsten welding arc (GTA). In the model, a boundary fitted coordinate system is adopted to describe precisely the cathode shape. The current-continuity equation has been solved with the combined arc plasma-cathode system, independent of the assumption of the current density distribution on the cathode surface, which was essential in previous studies of the arc plasma. The temperature distribution in pulsed GTA welding has been described and the transition processes of temperature contours and arc pressures at the anode center have been studied. Moreover, the effects of pulsed welding parameters on the dynamic processes of the arc pressure at the anode center have been studied using the developed model, the results being compared with experimental data measured by the micro-pressure sensor.