ARC STRUCTURE IN A MAGNETIC ANNULAR DISCHARGE

The structure of an arc in a magnetic annular discharge in hydrogen has been computed numerically using nonequilibrium, quasi-one-dimensional multicomponent hydrodynamics. The analysis substantiates recent experimental observations of a narrow current and ionization zone near the throat that is distinct from the complicated flow in the supersonic expansion. The numerical results suggest a simple diffusion and heating model for the subsonic portion of the arc. This model gives the important physical processes and permits the development of elementary relations that are useful for estimating parametric behavior. Specifically, formulas are derived giving the scale length of the discharge, fraction ionized, and the relationship between electrical power and flow parameters. Certain constants that are needed by the simple model are deduced by matching the results to the numerical analysis. © 1969 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.