M. Watanabe
A. Prosperetti
Dept. of Mech. Eng., Johns Hopkins Univ., Baltimore, MD 21218
The description of a bubble assembly, or cloud, by means of an ``effective medium'' approximation has found widespread application in the underwater acoustics community. In this approach the bubbly liquid is regarded as a continuum endowed with properties different from those of the pure liquid. In this study the effective medium results are compared with those of a direct numerical simulation in which the effects of the mutual interaction of the bubbles are simulated. A spherical assembly of bubbles immersed in an incompressible liquid is studied. The potential problem is solved numerically with a singularity expansion method including both volume pulsations and translational oscillations of the bubbles. Numerical results for both single realizations and ensemble averages are presented and discussed. [Work supported by the Office of Naval Research.]