Hydrodynamic effects in liquids subjected to pulsed low current arc discharges

Hydrodynamic phenomena in liquids associated with low current electrical discharges were analysed theoretically and the radial plasma column expansion was considered as an arbitrary discontinuity propagation. For assumed initial discharge channel radii of R₀ = 10^-6 and 10^-5 m, the initial temperatures in the discharge channel was found to be T ₀ = 1.4 × 10⁶ and 6.5 × 10⁴ K for a discharge current of I = 1 A, and T₀ = 6.5 × 10⁶ and 3 × 10⁵ K for I = 10 A. The temperature decreases during the initial ∼10^-8 s, due to radial plasma column expansion. During the initial 10^-8 s the velocity of the plasma column expansion exceeds the speed of sound in the undisturbed water (by 5-15 times), creating a shock wave in the water with a pressure discontinuity of ≈10⁵ atm, and a relaxation length of 10^-4 m.