Diagnostics on Steady-State Cross-Flow Arcs. I. Low Current

摘要

A novel cross-flow arc system was developed which permits the attainment of repeatable arc configurations, oriented in the vertical plane containing the horizontal upstream flow vector, symmetrical in cross-section, and symmetrical with respect to the mid-location between the electrodes. A bow-shaped arc is found at lower currents (less than about 20 amperes); a cusp-shaped arc is obtained at higher currents (greater than about 40 amperes). A transition regime is observed at intermediate levels. A unique optical system was developed in order to observe the arc simultaneously at many different azimuthal locations. With this system, together with the aid of an inversion method developed by Olsen et al, isotherm distributions within the arc were obtained for the first time. The experiments were conducted in Argon (at atmospheric pressure), at constant (low) speeds (43.8 cm/sec.) and constant electrode spacings (6.64 mm); arc current was varied in the range between 17.2 amperes and 34.1 amperes. The experiments demonstrated the cross-flow facility and the optical system to be valuable diagnostic devices. (Author)