Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
Single bubble sonoluminescence (SBSL) and ultrasound agent contrast (UAC), each one levitating in a standing wave field (30~70 kHz) inside of a spherical resonator filled with sterile water, are compared in order to understand their radial dynamics. Light scattering technique is employed to measure the radial pulsations of individual/cloud microbubbles. Waves emitted by bubble (shock wave) and the intensity of the acoustic field applied are measured through a needle hydrophone. UAC is highly diluted Polyson® microbubbles. Waveforms are processed by means of Fourier and time-frequency analysis. The experimental data and the main parameters involved (T, , Pa, Re and De) are analyzed as a function of short and long regimen. Linear and nonlinear oscillations were observed and associated with time-frequency spectra. Parametric instabilities are inferred from the light-scattered signal. The resting diameter and temperature are shown as principal parameters in the prediction of microbubble behavior.
