The Study on the Local Compression Effect on the Nozzle Arc

Using the insulated constrictor nozzle in the plasma jet generator, the arc column is elongated and the net input power supplied to arc is increased. When the constrictor length of the insulated constrictor nozzle is lengthened, the elongated are in it is expanded as approching the anode terminous and the wall compression effect on the elongated arc is decreased. When the nozzle cross section is decreased, the wall compression effect is increased, and also the nozzle heat loss is increased. The local compression effect on the forced elongated arc in the insulated constrictor nozzle is investigated in three kinds of nozzle, which are the ring constrictor nozzle (R-nozzle), the injection constrictor nozzle (P-nozzle) and the magnetic compression nozzle (H-nozzle). The voltage of R-nozzle is higher than that of the insulated constrictor nozzle with the same constrictor length (C-nozzle) by 3.9&acd