Baeva, M.Benilov, M. S.Almeida, N. A.Uhrlandt, D.2019-11-122019-11-122016Baeva, M., Benilov, M. S., Almeida, N. A., & Uhrlandt, D. (2016). Novel non-equilibrium modelling of a DC electric arc in argon. Journal of Physics D: Applied Physics, 49(24), 245205.http://hdl.handle.net/10400.13/2598A novel non-equilibrium model has been developed to describe the interplay of heat and mass transfer and electric and magnetic fields in a DC electric arc. A complete diffusion treatment of particle fluxes, a generalized form of Ohm’s law, and numerical matching of the arc plasma with the space-charge sheaths adjacent to the electrodes are applied to analyze in detail the plasma parameters and the phenomena occurring in the plasma column and the near-electrode regions of a DC arc generated in atmospheric pressure argon for current levels from 20 A up to 200 A. Results comprising electric field and potential, current density, heating of the electrodes, and effects of thermal and chemical non-equilibrium are presented and discussed. The current–voltage characteristic obtained is in fair agreement with known experimental data. It indicates a minimum for arc current of about 80 A. For all current levels, a field reversal in front of the anode accompanied by a voltage drop of (0.7–2.6) V is observed. Another field reversal is observed near the cathode for arc currents below 80 A.engNon-equilibrium modellingDC arcSpecies diffusionGeneralized Ohm’s lawNon-equilibrium boundary layer.Faculdade de Ciências Exatas e da Engenhariajournal article10.1088/0022-3727/49/24/245205