The Influence of Water Characteristics on Plasma-Containing Bubble Dynamics

Pulsed discharge in conductive water can produce a plasma-containing bubble and radiate intensive acoustic pulses. The bubble dynamics, which determines the characteristics of the acoustic wave, is sensitive to the water temperature and ambient pressure. This paper presents the high-speed records of plasma-containing bubble behavior under different water temperatures in the range 18 °C-80 °C and ambient pressure in the range 0.1-1 MPa. The results show that a higher water temperature generates a larger bubble, larger oscillation period, and higher efficiency of the conversion of electric energy into bubble energy. The bubble energy and energy efficiency increase fast with water temperature since the rise in the initial water temperature decreases the energy consumption during the predischarge period. The ambient pressure also has an obvious effect on the maximum bubble radius and oscillation period. Both of them decrease fast when the ambient pressure increases. But, the bubble energy and energy efficiency are not so sensitive to ambient pressure, which indicates that the ambient pressure has little influence on the parameters of pulsed discharge.