Static characteristics of a conduction and radiation dominated electric arc in nitrogen

The time-dependent energy and circuit equations are solved numerically to obtain temperature profiles, current-voltage characteristics and electric field strength vs axis temperature diagrams in the asymptotic region of a wall-stabilized electric arc operated in nitrogen. The numerical calculations demonstrate the splitting of the rising branch of the stationary solutions in the current-voltage characteristic. This phenomenon was earlier found experimentally for air. The computations were made for various channel radii and for various series resistances. The steady-state characteristics and convergence to the single branch of solutions is explained on the basis of the linearized Lyapunov stability theory. Comparison with available results of other authors shows that the analytical solution based on simple polynomial approximations to thermodynamic and transport functions differs significantly from numerical computations. (author) 11 figs., 21 refs