Theoretical estimation of sonochemical characteristics in a single cavitation bubble under various static pressure conditions

Abstract

Cavitation bubbles can be generated by introducing ultrasonic waves into the liquid. The growth and collapse of the bubbles transfer energy from ultrasonic waves to the gas mixture, resulting in the formation of an extreme environment with local high pressure and temperature, and then, multiple products (H2, ·OH, H·, O, H2O2, and so on) are produced. In the present study, the sonochemical characteristics inside an oxygen bubble have been investigated by using single bubble dynamics equations taking mass transfer, heat exchange, and chemical reactions into account. The effects of the equilibrium radius and static pressure on the temperature and the yields of H2, ·OH, and total oxidants inside the bubble are analyzed. There are optimal equilibrium radii that maximize gas temperature and the amounts of H2, ·OH, and total oxidants under different static pressures. The results of this paper are in good agreement with the previous results and can be used to explain sonochemical phenomena observed in experiments.