The Absorption of Sound in Suspensions of Irregular Particles

The greater part of the absorption of sound in aqueous suspensions of small spherical particles can be attributed to the viscous drag between the fluid and the particles in the sound field. The absorption resulting from this process is found to agree with that obtained by Lamb in another manner. The applicability of the theoretical result to suspensions of irregular particles is examined by means of measurements on sand and kaolin suspensions, using a pulse-reflection method at megacycle frequencies. Approximate agreement with the idealized theory is found as the particle size, viscosity, and frequency are varied.