COUPLED PHASE THEORY FOR SOUND-PROPAGATION IN EMULSIONS

The coupled phase approach is extended to model sound propagation in a n emulsion of two compressible, thermoviscous liquids. This provides a n alternative to scattering theory for modeling sound propagation in e mulsions in the low-acoustic radius regime. Predictions of the new the ory are compared with predictions of multiple-scattering theory and ex perimental results fur ultrasonic velocity and attenuation in an emuls ion. For the particular set of experimental data used here, the couple d phase theory gives predictions close to the scattering theory predic tions, and a better prediction of the dependence of the attenuation on volume fraction. A similar difference between the two theoretical app roaches has been found in earlier work on coupled phase models for sou nd propagation in suspensions. (C) 1997 Acoustical Society of America.