Bubble growth in viscous and non-viscous liquids following a localized electrical discharge

Localized electrical discharges have been used to generate vapor bubbles in dielectric liquids, and the growth and collapse of these bubbles has been recorded photographically. The optical studies are based on a flash-illuminated shadowgraph apparatus. The expansion and collapse of a cavity in the low viscosity limit follows a simple hydrodynamic model and the predictions of the model are experimentally confirmed. The effects of discharge energy on bubble growth have been investigated. and we find that only about 1% of the circuit energy is transferred to kinetic energy of the expanding cavity. Analysis of bubble expansion in the viscous case is more complicated, but a particular case of nonuniform viscosity leads to a solution that is in reasonable agreement with the experimental results.