Metallic jet production using pulsed electrical discharges in water

Summary form only given, as follows. Capacitor-bank driven pulsed electrical discharges in water can create high pressures, of the order of several tens of kilobars. Such pressures have industrial applications, such as in rock fragmentation. We report, for the first time, the use of such discharges to accelerate thin metallic liners to high velocities. The liners turn into high-velocity jets which can perforate metal sheets. This experiment make use of a l5 kV, 60 kJ capacitor bank. The bank delivers energy to the load through a coaxial cable. The load is a fluid filled cavity consisting of a right circular cylinder, one end of which is heavily tamped. The other end is bounded by a conical copper liner. The cavity is filled with a viscous fluid. Discharge of the capacitor bank dumps energy in a small region of the fluid, producing a high pressure "hot zone". The resulting shock/pressure waves produce liner collapse and acceleration, leading to a high-velocity jet. Approximate measurements indicate that the velocity lies in the range of 1.4-1.6 km/s. We have studied the performance of these jets for metal sheet perforation. Jets produced by a copper liner has perforated up to 5 mm of aluminium sheet. The design and performance of this system will be discussed in the paper.