Effects of a Transverse Magnetic Field on a Constricted Electric Arc

Abstract

The interaction of a constricted electric arc (argon at 1 atm) with an applied perpendicular magnetic field has been investigated analytically. The resulting (two-dimensional) flow and temperature fields, conductive and radiative wall heat transfer, and voltage-current characteristics of the arc are predicted. Three characteristic parameters are isolated: (I/a = current/tube radius), (Re = Lorentz and viscous force parameter), (RT = radiation parameter). When radiation is negligible, the first two are sufficient to scale the effects of any combination of current, tube radius, and applied magnetic field strength. A twin vortex flow pattern is predicted, with the displacement of the vortex “eyes” greatest for high applied magnetic fields and low currents. Comparisons with experimental results from the literature are good to satisfactory.