Experimental and theoretical study of a direct-current arc in an orifice nozzle flow

Abstract

To increase the basic knowledge about the interaction between an arc near zero current and flows affected by strong shock waves, an investigation was conducted to determine the d.c. arc characteristics at a current of approximately 100 A in an orifice nozzle. Various nozzle pressure ratios were used to produce subsonic and supersonic flows. Cold-flow measurements were used to calculate the arc electrical parameters based on the arc energy integral theory. The calculated results agreed reasonably well with the experimental measurements. It can be concluded that the convection cooling of the arc is the dominant arc cooling process for most currents. Nomenclature= constants in mass flux equation C = sonic velocity C p = specific heat at constant pressure E = electric field strength e = thermal, kinetic, and potential energy per unit mass h = enthalpy / = current j = current density K M P R r r 0 R(z) T T 0