Skip to Main content Skip to Navigation
Theses

Réponse mécanique d'une mousse liquide à une injection d'air ou à une onde acoustique.

Abstract : This thesis presents experimental and theoretical results on the rheological behavior and the acoustic properties of liquid foams. The foams used in these studies are two-dimensional (2D) foams for the rheological studies and three-dimensional (3D) foams for the acoustic experiments. In the first part of this thesis, which considers the rheology of foams, we studied how a 2D foam subjected to localized air injection behaves, focussing on the effect of different overpressures of injected air. At low overpressure, a central bubble forms that swells by separating the neighboring bubbles of the foam by successive rearrangements (T1s), without breaking any films : this behavior is similiar to the ductile fracture of materials. At intermediate overpressures, there is a short axisymmetric transition, then the central bubble takes a fingered shape. At high overpressure, successive ruptures of films occur along a narrow crack and the foam is broken as a brittle material. In the ductile regime, we studied the elastoplastic response to a slow expansion of the central bubble ; with a higher rate of expansion, we showed that the response of the foam is mainly related to the wall friction. This allowed us to predict the relationship between the overpressure and the expansion ratio, and the fingering. We finally studied the criteria for transition between the ductile and brittle regimes. The second part of this thesis focusses on the field of acoustics of liquid foams. We have studied the propagation of an acoustic signal in a 3D foam and measured the sound velocity and attenuation during the foam's coarsening. We have demonstrated resonant behavior of the foam, with a minimum sound transmission corresponding to a well-defined bubble size. We compared our results to the acoustic resonance of a single bubble.
Complete list of metadatas

Cited literature [76 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00765661
Contributor : Imen Ben Salem <>
Submitted on : Saturday, December 15, 2012 - 9:11:29 PM
Last modification on : Tuesday, January 12, 2021 - 4:42:16 PM

Identifiers

  • HAL Id : tel-00765661, version 1

Citation

Imen Ben Salem. Réponse mécanique d'une mousse liquide à une injection d'air ou à une onde acoustique.. Mécanique des fluides [physics.class-ph]. Université Rennes 1, 2012. Français. ⟨NNT : 0fg9gi006t9⟩. ⟨tel-00765661⟩

Share

Metrics

Record views

889

Files downloads

8483