Three-dimensional time-dependent non equilibrium modeling of arc and jet dynamics in DC plasma torches

Summary form only given. The industrial relevance of thermal plasmas has motivated the development of more detailed mathematical and numerical models for their realistic simulation. Recent modeling results have emphasized the necessity for non- equilibrium models for the realistic simulation of these flows. In this research, a three-dimensional, time-dependent, non- equilibrium (two-temperature) model is applied to the simulation of the flow through a commercial DC arc plasma torch and the generated jet. The mathematical and numerical models, as well as the geometry and boundary conditions used, are similar to those in [1]. The numerical results for Ar plasma show marked thermal non-equilibrium in the interface between the jet and the surrounding gas (indicated by the arrow), as evidenced by high values of electron temperature T_e and the thermal non-equilibrium parameter. This result is significant because the high values of T_e can have a marked effect on the chemistry of the plasma and the processing material. In addition, the results are able to reproduce the large scale structures of the jet caused by the forcing produced by the arc dynamics inside the torch.