Acoustic waves in violently collapsing bubbles

Among Miguel Junger’s many contributions to acoustical science and engineering were his papers and presentations on bubble acoustics. Among his many contributions to the well being of his colleagues at Cambridge Acoustical Associates was the mentoring of this presenter during the latter years of graduate study at MIT. Hence, this presentation in this session. In an evaluation of five reduced models for spherically symmetric bubble collapse and rebound [J. Appl. Phys. 112, 054910 (2012)], it was found that some recent models, which incorporate wave propagation in both the external fluid and internal gas, did not perform as well as the long-established model by Keller and Kolodner, which incorporates wave propagation in the fluid but not in the gas [J. Appl. Phys. 27, 1152–1161 (1956)]. Performance was assessed through comparisons against response histories produced by finite-difference solution of the Euler equations under adiabatic conditions. Further investigation revealed that neither acoustic-wave nor shock-wave propagation in the gas was apparent, but that a standing wave in the gas was. This prompted an enhancement of the Keller and Kolodner model that accounts for the standing wave. The formulation and evaluation of the enhanced model is the subject of this presentation.