Modeling of the flow, temperature and concentration fields in an arc plasma reactor with argon-nitrogen atmosphere

A mathematical formulation was developed for describing the flow behavior, temperature profile and concentration fields in pure or mixed argon and nitrogen arc plasmas impinging on a metal target inside a reactor. The simulation involves solution to conservation equations of mass, momentum, energy, k-ε model, chemical species, and current continuity. "Combined" diffusion coefficients were used in chemical species conservation to account for all species present in the plasma. An increase in the proportion of nitrogen introduced in the reactor results in higher arc velocity and temperature, reduced arc column diameter and increased heat flux imparted to the metal target. Demixing resulted to an increase of mass fraction of nitrogen at the central portion of the arc.