000014929 001__ 14929 000014929 005__ 20161115100206.0 000014929 04107 $$aeng 000014929 046__ $$k2016-08-21 000014929 100__ $$aLeroy, Valentin 000014929 24500 $$aAcoustical properties of liquid foams (INVITED) 000014929 24630 $$n24.$$p24th International Congress of Theoretical and Applied Mechanics - Book of Papers 000014929 260__ $$bInternational Union of Theoretical and Applied Mechanics, 2016 000014929 506__ $$arestricted 000014929 520__ $$2eng$$aSound velocity and attenuation measurements in well-characterized liquid foams were performed over a wide frequency range (1-600 kHz). The study was limited to the long wavelength case: even for the highest frequencies explored, the wavelength was larger than the typical size of the micro-structure of the foams. Typical results are shown, for a foam with a liquid volume fraction of 10%. A strongly dispersive behavior was found, with three regimes of propagation: at low frequencies, the effective velocity was 33 m/s, as predicted by Wood’s law; at high frequencies, the velocity was of the order of 220 m/s; in the intermediate regime, velocity and attenuation varied strongly with frequency, presenting the typical features of a low frequency resonance. A new model is proposed, based on the coupled displacements of films, liquid channels and gas in the foam. 000014929 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb. 000014929 653__ $$a 000014929 7112_ $$a24th International Congress of Theoretical and Applied Mechanics$$cMontreal (CA)$$d2016-08-21 / 2016-08-26$$gICTAM2016 000014929 720__ $$aLeroy, Valentin 000014929 8560_ $$ffischerc@itam.cas.cz 000014929 8564_ $$s56076$$uhttps://invenio.itam.cas.cz/record/14929/files/TS.FS09-2.01.pdf$$yOriginal version of the author's contribution as presented on CD, page 3430, code TS.FS09-2.01 . 000014929 962__ $$r13812 000014929 980__ $$aPAPER