Analytical study of the acoustic field in a spherical resonator for single bubble sonoluminescence

DAMIÁN H. DELLAVALE; RAÚL URTEAGA; FABIÁN J. BONETTO

JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA

ACOUSTICAL SOC AMER AMER INST PHYSICS

Año: 2009 vol. 127 p. 186 - 197

0001-4966

The acoustic field in the liquid within a spherical solid shell is calculated. The proposed model takesinto account Stoke’s wave equation in the viscous fluid, the membrane theory to describe the solidshell motion and the energy loss through the external couplings of the system. A point source at theresonator center is included to reproduce the acoustic emission of a sonoluminescence bubble.Particular calculations of the resulting acoustic field are performed for viscous liquids of interest insingle bubble sonoluminescence. The model reveals that in case of radially symmetric modes of lowfrequency, the quality factor is mainly determined by the acoustic energy flowing through themechanical coupling of the resonator. Alternatively, for high frequency modes the quality factor ismainly determined by the viscous dissipation in the liquid. Furthermore, the interaction between thebubble acoustic emission and the resonator modes is analyzed. It was found that the bubble acousticemission produces local maxima in the resonator response. The calculated amplitudes and relativephases of the harmonics constituting the bubble acoustic environment can be used to improvemulti-frequency driving in sonoluminescence.