Numerical characterization of the plasma arc with various Ar-CO₂ mixtures

Plasma technology finds applications in many industrial areas. To improve the process efficiency, different plasma forming gases and their mixtures are used. Since CO₂ is economical and has high thermal conductivity, it is identified as a potential candidate in plasma material processing. However, the characteristics and merits of CO₂ plasma arc in material processing are scanty. In this work, a 2D model is built to simulate plasma arc with CO₂ and its mixtures with Ar. Effects of arc current, gas composition and arc length on the arc heating efficiency and arc characteristics are discussed. The arc size is strongly influenced by the gas composition at 200 A than at 100 A. Temperature distribution in the arcs is wider when CO₂ content is decreased. The effect of arc current on the arc heating efficiency is stronger at lower current. Results predicted by the present model are compared with measured data for model validation.