ACOUSTIC DISPERSION AND ATTENUATION RELATIONS IN BUBBLY MIXTURE

Multiple scattering in bubbly mixture can be studied using a many-body theory, which in principle is able to include any order interactions in a many-body system. In this paper, the theory is first described in an illustrative manner, and then applied to the case of a bubbly mixture. As an initial step, consideration is given to up to second-order interactions of bubbles, and the effective wave number of the average scattered field is derived. The result provides a higher-order correction to previous results that have generally neglected mutual interactions of bubbles. The phase speed and amplitude attenuation of acoustic waves in the mixture are calculated from the effective wave number. Numerical results show that the higher-order correction can be rather significant under certain circumstances. The primary purpose of this paper is to present a relatively simple and systematic approach to such problems as described here. The work can also be extended to include higher-than-second-order interactions, which remains to be the subject of future research. (C) 1995 Acoustical Society of America.