Abstract (Invited)

Acoustics of Aqueous Foams Contain Solid Particles

I.Shreiber (Department of Mecanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel); I.Goldfarb (Department of Mathematics, Ben-Gurion University of the Negev, Beer-Sheva, Israel); V.Feklistov (Institute for the Earth Cryosphere, Siberian Branch RA of Sciences, Tyumen, Russia)

e-mail: isaak@bgumail.bgu.ac.il

Results of theoretical and experimental study of acoustics of three-phase foams (gas-liquid foam, a liquid phase of which contains solid particles)are presented in the paper. The research focuses on the peculiarities of the acoustic waves propagation through the three-phase foams. It is shown that a small concentration of the solid particles leads to the growth of the sound wave velocity and increasing of attenuation coefficient. It is found that when the concentration of the solid particles becomes large enough, the attenuation coefficient decreases sharply. In accordance with the suggestion made the hydrodynamic resistance erupting due to liquid flow throw a system of the Plateu-Gibbs channels mainly governs the phenomenon of attenuation. A small addition of the particles increases the hydrodynamic resistance and causes the growth of the attenuation coefficient. When the concentration of the particles overcomes some critical value, they "cork up" the Plateu-Gibbs channels and liquid flow throw them becomes impossible. In turn the impact of the hydrodynamics into the attenuation coefficient becomes close to zero and its total value falls down. A dependence of theoretical value of solid particles concentration on the problem parameters is investigated. The results of the theoretical study are verified by the experimental measurements and numerical simulations. The comparison demonstrates a good accuracy of the suggested model.

Section : 4