Resonant acoustic propagation and negative density in liquid foams.
We measured the dispersion relation for acoustic longitudinal waves in liquid foams, over a broad frequency range (60-600 kHz). Strong dispersion was found, with two nondispersive behaviors, separated by a negative density regime. A new model, based on the coupled displacements of films, liquid channels, and gas in the foam, rationalizes all the experimental findings.
Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 75205 Paris cedex 13, France.
Juliette
J
Pierre
Institut de Physique de Rennes, Université Rennes 1, CNRS (UMR 6251), Rennes 35042, France.
Benjamin
B
Dollet
Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 75205 Paris cedex 13, France.
Valentin
V
Leroy
D000162:Acoustics; D008956:Models, Chemical; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D055682:Viscoelastic Substances / Q000737:chemistry*; D014966:Xanthenes / Q000737:chemistry
D055682:Viscoelastic Substances; D014966:Xanthenes; D012967:Sodium Dodecyl Sulfate