Numerical calculations of the properties of axially symmetric arc columns

Abstract

Numerical solutions of the energy-balance equation of an axially symmetrical uniform arc column are outlined and illustrated with results pertaining to a nitrogen plasma at atmospheric pressure. Published data on the electrical conductivity, thermal conductivity and radiated power density of nitrogen plasmas have been reviewed. The data selected for subsequent calculations of arc properties are summarised in Table 1 and Figs. 2, 3 and 4. Reasons for selecting these data are discussed. Using the selected data, temperature distributions (T(r)), are radii (R), arc currents (I) and radiation losses (U), are calculated for arc columns in which the axial temperature, To, and the voltage gradient, E, have been specified. Results are summarised by a series of graphical plots (Figs. 8, 9 and 10) of arc similarity parameters I/ER², U/R², El-U, against the axial temperature, To. The purpose of the calculations is to provide data for comparison with experimental measurements on magnetically propelled arcs.