Rheology of a 2D granular film
Résumé
We study experimentally the rheology of a macroscopic particle-laden soap film, designated as a “Granular Film”, in the simple shear configuration. The macroscopic particles are dispersed in a soapfilm, while being large enough that they bridge both fluid interfaces. We simultaneously performmacroscopic rheological measurements with a classical rheometer and investigate interactions at theparticle scale with a camera underneath the film. The determination of the velocity field of thegrains reveals the presence of an inhomogeneous shear within the granular film. Trying to correlateboth measurements unveil the non-locality of the rheology of the granular film: similarly to whathave been observed in dry granular material, we find an highly-sheared zone close to the moving wallcontrasting with a large quasistatic area. This behavior can be accounted for through an extendedkinetic theory and correlated with a transition in the dominant component of the stress.
Domaines
Matière Molle [cond-mat.soft]
Origine : Publication financée par une institution