Voltage Gradients in Turbulent Arcs

Abstract

A plausible formulation is offered relating the changes in resistivity or average voltage gradient at high flow rates to the fluctuations in gas temperature and velocity. A four-fold increase with flow rate in voltage gradient as observed by Frind and Damsky in an argon arc can be accounted for by a 10 to 20% r.m.s. fluctuation in gas temperature. The increase also depends on the ratio of electron neutral collision frequency to the total collision frequency, and thus tends to become smaller as the gas becomes singly ionized. In transitions to higher order Z ionizations, the theory predicts that the average resistivity may be slightly increased, and then with a rise in temperature, it is decreased below its nonturbulence values.