Modeling of the Electroacoustic Process of Incomplete Spark Discharge in Saline Water-Sparker Source

Incomplete spark discharge is known to generate oscillating bubbles and intense shockwaves in saline water, but the electroacoustic process is still not well understood. We develop a phenomenological model and describe the electroacoustic process, with a revised plasma resistance equation and a simple water resistance model. The simulation results agree well with experimental results under different charging voltages and capacitances, including the load electrical waveforms, bubble dynamics, and acoustic waves. Furthermore, the model can successfully calculate the electrical energy consumed in the plasma channel. The simulation results indicate that the energy efficiency decreases with increasing charging voltage, but increases with the increase of the charging capacitance. We also found that the shockwave peak and width increase as power-law functions of the discharge energy. In addition, the shockwave peak is more sensitive to the charging voltage, whereas the shockwave width is influenced by the charging capacitance more obviously. Finally, the proposed model confirms again that hydraulic efficiency and electroacoustic efficiency decrease when the charging voltage increases, but they increase with increasing capacitance. Overall, the phenomenological model is practical and this work helps in developing incomplete-discharge sparker sources applied in oceanic seismic explorations.