Long-wave sound absorption in suspensions

The study of the phenomenon of absorption and scattering of sound waves in inhomogeneous systems is of great fundamental and practical importance. A suspension consisting of solid particles in a liquid is one of such inhomogeneous systems. In many suspensions, the particles are spherical (or can be considered as such). The present study deals with spherical particles in the long-wave range (particle size is much smaller than wavelength). It determines main characteristics of this phenomenon depending on the particle size, concentration and length of acoustic waves. Two approaches to the absorption and scattering of waves are considered: the Urick model and the ECAH theory. It is shown that in suspensions with small particle sizes the main mechanism of attenuation of ultrasonic waves is viscous-inertial losses. In suspensions with large particle sizes scattering losses prevail.