Spark gap switch having a two-phase fluid flow

Abstract

A two-phase fluid is injected into a volume upstream of the spark gap flow channel of a spark switch. The injected two-phase flow can be separated, causing the liquid component of the two-phase fluid to form a layer adjacent the wall of the flow channel and a predominately gas phase region near the spark switch electrodes. This distribution of liquid and gas phases can be achieved by tangential injection of the two-phase fluid. The resulting two-phase flow absorbs the thermal and radiant energy produced by the spark in the spark channel, as well as the energy of the shock wave systems produced by the spark in the spark channel, thereby reducing the temperature that the wall of the spark gap would attain without such two-phase fluid flow injection. Vaporization of the liquid due to this energy absorption generates a substantial gas flow which increases the purge flow and recovery rate of the spark gap switch. The spark gap switch flow channel and the expansion duct to which the spark switch is attached, can be tuned to produce an unsteady purging flow through the spark channel, thereby rapidly removing the hot gas residues caused by the preceding spark from the spark channel and restoring the pressure and density in the spark gap to the initial levels. In one embodiment, the two-phase fluid can be a mixture of water droplets and steam.