Addressing the symmetry of a converging cylindrical shock wave in water close to implosion

We report experimental and numerical results relevant to the dynamics in the vicinity of the implosion axis of a strong shock wave generated by an underwater electrical explosion of a cylindrical array. Experiments were conducted using both sub-microsecond and microsecond timescale pulsed generators with stored energy up to similar to 5kJ, delivering similar to 420/350kA with a 320/1000ns rise time pulses to the array, respectively. The backlighted images of the converging shock wave and the light emission around the cylindrical axis indicate strongly that the shock wave front keeps its azimuthal uniformity as far as r approximate to 30 mu m. Also, images obtained almost simultaneously with the implosion suggest symmetric convergence <2ns prior to the shockwave's arrival to the axis. In addition, the light emission obtained by a photo-multiplying tube suggests the existence of a 200ns long, almost constant, strong afterglow immediately following the light emission peak related to the implosion.

Automated summary

The study investigates the dynamics of a strong shock wave generated by an underwater electrical explosion near the implosion axis. Experimental results show that the shock wave front maintains azimuthal uniformity up to approximately 30 micrometers, with a strong afterglow lasting for about 200 nanoseconds following the implosion-related light emission peak.