Incorporation of thermal overlap effects into multiple scattering theory

Existing multiple scattering theories do not give accurate predictions of t he ultrasonic properties of concentrated emulsions because overlap of therm al waves generated by the droplets in the presence of an ultrasonic field i s not taken into account [McClements, J. Acoust. Sec. Am. 91, 849-853 (1992 )]. Recently, a core-shell model was developed which accounts for the effec ts of thermal overlap, but ignores multiple scattering, intrinsic absorptio n and visco-inertial effects [Hemar et al., J. Phys. TI 7, 637-647 (1997)]. A multiple scattering theory is combined with the core-shell model to obta in a new theory that overcomes the limitations of each of the individual th eories. The new theory gives excellent agreement with experimental measurem ents of the attenuation spectra of concentrated monodisperse emulsions. (C) 1999 Acoustical Society of America. [S0001-4966(99)02902-1].