Intensity of oscillation of spark-generated bubbles

In this paper, a new measure of bubble oscillation intensity is introduced, defined as a non-dimensional peak pressure in the first bubble pulse. An iterative method for determining the bubble size and bubble oscillation intensity from a record of the acoustic pressure wave emitted by an oscillating bubble is proposed. Using this procedure the sizes and intensities are determined for a set of pressure records obtained in recent experiments with spark-generated bubbles. It can be seen that in these experiments the bubble sizes, as defined by the first maximum bubble radius, R_M1, ranged from 12.8 to 56.4 mm, and the bubble oscillation intensities, as defined by the non-dimensional peak pressure in the first bubble pulse, p_zp1, ranged from 14.3 to 174. Data obtained in the experiments are compared with data computed in a theoretical model and it is shown that there are differences between the theory and experiment. These differences are attributed to energy losses from the real bubbles not taken into account in the theoretical model.