THE BEHAVIOR OF DYNAMIC ELECTRIC ARCS
MICHIGAN UNIV ANN ARBOR ANN ARBOR
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The thermal structure of an AC arc was studied both experimentally and analytically. In order to provide a reasonable description of the manner in which the dynamic arc behaves as a circuit element, it is first necessary to solve the partial-differential equation that describes the energy-transfer processes within the arc column. In the idealized situation, where the arc is characterized by strict cylindrical symmetry and the electrodes have little effect on the positive column, certain limiting closed-form solutions have been obtained from the appropriate boundaryvalue problem. In the general case, the problem has been solved on a digital computer. In all cases, a simplified relationship between the electrical conductivity and the plasma temperature was assumed. The theoretically derived waveforms for electric-field strength and current bear a close relationship to those found by experiment. The latter results were obtained from a cascade-tube arc such as that employed by Maecker for his DC work. The present device was excited by 60-cps AC power, and rms currents up to 30 A were employed. Nitrogen, and argon were the working gases.
- Plasma Physics and Magnetohydrodynamics