Efficiency of energy conversion in underwater spark discharges and associated bubble oscillations: experimental results

In this paper low-voltage high-energy spark discharges in water and associated bubble oscillations are studied experimentally. Pressure waves emitted during spark discharges and during following bubble oscillations have been recorded and analyzed to determine the radiated acoustic energy and potential energy of the bubbles. These energies are then used to determine the efficiency of energy conversion. For example, it has been found out that only 2% to 8% of electrical energy stored in the capacitor bank is converted into the potential energy of the bubble at its first maximum volume and only about 30% of this potential energy is radiated as acoustic energy in the first bubble pulse ...