Efficient target acceleration using underwater electrical explosion of wire array

The results of experimental studies together with numerical and analytical modeling showed that the acceleration of a target by employing the shock compression and water flow generated by the underwater electrical explosion of a wire array can be considered an efficient (up to ∼20%) approach. In experiments, a pulse generator with stored energy of ∼6.5 kJ, current amplitude of ∼380 kA, and rise time of ∼1.2 μs was used for underwater electrical explosion of a copper wire planar array. Streak shadow imaging and photonic Doppler velocimetry were applied to study the time-resolved velocity of the shock in water and an aluminum target in air, respectively. The targets, having different thicknesses and designs, were positioned at variable distances from the array. Experimental results showed that the target velocity evolution is characterized by an ns-timescale rise time peak with a subsequent decrease, which transfers to a μs-timescale increase up to its saturated value. Target velocities of up to 1360 m / s were measured. The experimental, numerical, and analytical modeling results showed that a temporally unmovable barrier, located between the exploding array and the target, allows one to increase the pressure in that location, which leads to higher shock velocity in the target.