Underwater Electrical Explosion of Wires and Wire Arrays and Generation of Converging Shock Waves

Electrical and Acoustic Parameters of Wire-Guided Discharges in Water: Experimental Determination and Phenomenological Scaling

“…This is in agreement with [25], where an analytical equation for the total acoustic energy in the pressure impulse generated by an underwater discharge was shown to be directly proportional to the integral of the squared pressure signal and the length of the wire, . Using (6) and (9), the link between the peak acoustic magnitude, P ac , and the total energy deposited into the plasma channel, W(T), can be derived: Equation (11) follows the form of the empirical relationship between the peak acoustic magnitude produced by a spark discharge in water and the corresponding energy available in the spark discharge used in [26], where it was shown that (11). Fig.7 shows experimental values of the peak acoustic magnitude plotted against the total energy available in the wire-guided discharge for all three wire lengths, all capacitances and all charging voltages.…”

“…Fig.7 shows experimental values of the peak acoustic magnitude plotted against the total energy available in the wire-guided discharge for all three wire lengths, all capacitances and all charging voltages. The dashed lines represent the fitting obtained by (11), c 2 was a variable parameter, c 2 = 0.22  0.02, which confirms the value of c 2 = 0.238 obtained using combination of (6) and (9). The good fit between the experimental data and the behavior predicted by (11) confirms that the phenomenological scaling relationships proposed in the present work can satisfactorily describe the functional dependency of the acoustic magnitude on the energy delivered to the discharge and the plasma resistance.…”

“…The dashed lines represent the fitting obtained by (11), c 2 was a variable parameter, c 2 = 0.22  0.02, which confirms the value of c 2 = 0.238 obtained using combination of (6) and (9). The good fit between the experimental data and the behavior predicted by (11) confirms that the phenomenological scaling relationships proposed in the present work can satisfactorily describe the functional dependency of the acoustic magnitude on the energy delivered to the discharge and the plasma resistance. These relationships provide a mechanism for the optimization of practical acoustic wire-guided discharge sources.…”

“…Water has low compressibility, which results in slow radial expansion of the plasma developed in the initial stage of the underwater wire discharge, 10 5 cm/s. This expansion velocity is almost two orders of magnitude lower than the plasma expansion velocity in the case of a wire explosion in vacuum [11]. Therefore, due to the high current magnitude and high plasma density U developed in an underwater plasma channel, the equation of state of the warm dense matter formed in the breakdown channel, and the electrical conductivity of this matter, can be obtained and investigated [12].…”

“…For example, fast electrical disintegration of metallic conductors in water can be used for fabrication of nanomaterials (metallic and metal oxide nanoparticles) [9], and for generation of high residual stresses in metallic parts [10]. Underwater wire-guided discharges are used in investigation of the conductivity and equations of state of warm dense matter [11,12]. Water has low compressibility, which results in slow radial expansion of the plasma developed in the initial stage of the underwater wire discharge, 10 5 cm/s.…”