The results of experimental and numerical research of shockwaves generated by the underwater electrical explosion of a single wire and a planar wire array are reported. Experiments were conducted using a microsecond time scale pulse power generator delivering a <210 kA current with a <1 μs rise time. Streak and fast framing cameras were used to study the time- and space-resolved evolution of the shocks. The results show that (a) an aperiodic discharge constitutes the most efficient method of generating a shockwave; (b) in the case of a planar wire array, an almost simultaneous explosion can be obtained when the individual wire diameter is 2 × 10⁷ A/cm²); (c) the planar shock velocity can be accelerated using the combustion properties of the Al wires efficiently, and (d) the shock velocity can be enhanced using a metal reflector placed below the 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 $1360\mathrm{m}/\mathrm{s}$ 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.

We report the results of experiments investigating the implosion of a shock generated by the electrical explosion of a cylindrical aluminum wire array immersed in a >80% hydrogen peroxide/water solution. This solution was chosen as an additional energy source to the supplied electrical energy to generate the imploding flow with higher velocity. The experiments were conducted using a generator with the stored energy of ∼4.8 kJ, delivering to the array a ≤280 kA current rising during ∼1 μs. The backlighted images of the imploding shocks were recorded using a streak camera. Using different diameter wires, the explosion of arrays, characterized by critically damped and under-damped discharges, was studied. The experiments revealed that an array explosion in a 92% H₂O₂/H₂O solution results in the second strong shock generated after the peak of the deposited electrical power, a solid indication of H₂O₂ detonation. This second shock converges ∼40% faster than the first strong shock generated by the wire explosion. One-dimensional hydrodynamic simulations of the shock convergence in H₂O₂/H₂O solutions support this proposition.

We present a new technique for the investigation of shock-driven hydrodynamic phenomena in gases, liquids, and solids in arbitrary geometries. The technique consists of a pulsed power-driven resistive wire array explosion in combination with multi-MHz synchrotron radiography. Compared to commonly used techniques, it offers multiple advantages: (1) the shockwave geometry can be shaped to the requirements of the experiment, (2) the pressure (P > 300 MPa) generated by the exploding wires enables the use of liquid and solid hydrodynamic targets with well-characterized initial conditions (ICs), (3) the multi-MHz radiography enables data acquisition to occur within a single experiment, eliminating uncertainties regarding repeatability of the ICs and subsequent dynamics, and (4) the radiographic measurements enable estimation of compression ratios from the x-ray attenuation. In addition, the use of a synchrotron x-ray source allows the hydrodynamic samples to be volumetrically characterized at a high spatial resolution with synchrotron-based microtomography. This experimental technique is demonstrated by performing a planar Richtmyer–Meshkov instability (RMI) experiment on an aerogel–water interface characterized by Atwood number $A_0\sim -0.8$ and Mach number $M\sim 1.5$ . The qualitative and quantitative features of the experiment are discussed, including the energy deposition into the exploding wires, shockwave generation, compression of the interface, startup phase of the instability, and asymptotic growth consistent with Richtmyer's impulsive theory. Additional effects unique to liquids and solids—such as cavitation bubbles caused by rarefaction flows or initial jetting due to small perturbations—are observed. It is also demonstrated that the technique is not shape dependent by driving a cylindrically convergent RMI experiment.

We present the results of the research on underwater electrical explosion of planar copper wire arrays, accompanied by the generation of a planar shock, using the synchrotron-based phase-contrast radiography imaging capabilities of the ID19 beamline at the European Synchrotron Radiation Facility. It is shown that the interaction of a strong shock with an air–water interface leads to additional acceleration of the wire expansion due to a rarefaction wave along with the emergence of micro-jets. In the case of a target placed above the array, we observed the formation of a cavity between the array and the target due to the interaction of two rarefaction waves. The results of two-dimensional hydrodynamic simulations of the wire explosion and the interaction of the generated shock with the water–air and water-target interfaces showed good agreement with experimental results.

We present results on underwater electrical explosions of thin aluminum and copper foils using a generator delivering ∼200 kA current amplitude, ∼0.9 μs rise time pulses. Time-resolved shadow imaging displays the generation of a strong planar shock wave in water in the vicinity of the exploding foil. Using time-resolved spectroscopy, aluminum oxide (AlO) absorption bands were observed in a Planckian-like spectrum, indicating that aluminum combustion starts when aluminum vaporizes. It is also shown that the strongest shock wave is obtained for the largest linear energy deposition rate to the foil.