Two-Dimensional Numerical Modeling of Direct-Current Electric Arcs in Nonequilibrium

A numerical model has been developed to analyze arc-anode attachment in direct-current electric arcs. The developed model fully couples a plasma flow with electromagnetic fields in a self-consistent manner. Electrons and heavy species are assumed to have different temperatures. Species continuities are taken into account to address the chemical nonequilibrium with the Self-Consistent Effective Binary Diffusion (SCEBD) formulation. Electric and magnetic field equations are determined with a newly developed Ohm’s law, an improvement over the conventional generalized Ohm’s law. The governing equations are discretized and solved using the Finite Volume Method (FVM) and Gauss–Seidel Line Relaxation (GSLR) method in a two-dimensional domain. The model is applied to a two-dimensional axisymmetric high-intensity argon arc. The results are compared favorably with experimental and other numerical data. A significant electric potential drop has been observed in the vicinity of the anode due to the thermal and chemical nonequilibrium effects.