Modelling of tungsten inert gas arc and its impact on the anode
An unified mathematical model of plasma column and anode region of electric arc with refractory cathode in inert gas of atmospheric pressure, in particular welding arc in TIG welding, is described. An essential feature of this model is the possibility of taking into account the non-uniformity distribution of anode voltage fall in the region of anode binding of the arc, that allows a more adequately description of the electric current distribution in the near-anode plasma. The model allows calculation of thermal, gas-dynamic and electromagnetic characteristics of arc plasma, as well as the characteristics of its thermal, electric and force impact on the anode surface, depending on the arc current and length, kind of shielding gas and anode material. Model testing and verification were performed, the results of which are indicative of the model adequacy and its applicability for numerical study of the above characteristics.