Periodic order induced by horizontal vibrations in a two-dimensional assembly of heavy beads in water

Régis Wunenburger (1) , V. Carrier (2) , Yves Garrabos (3)

1 LPS - Laboratoire de Physique Statistique de l'ENS
2 CRPP - Centre de recherches Paul Pascal
3 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

We report on the observation of the periodic pattern occuring in a two-dimensional (2D) assembly of heavy beads (of diameter D = 280-630 μm) immersed in water when the vessel containing the fluid and the beads is submitted to horizontal vibrations (of frequency f and oscillation amplitude A). Under vibrations, regularly spaced, one bead thick lines perpendicular to the direction of vibrations are formed at small surface fraction. In the ranges f = 10-20 Hz and A = 0.7-3.5 mm, the amplitude of the oscillatory motion of the beads relative to the fluid B is found to vary linearly with A. A simple phenomenological model based on dynamic solid friction and viscous drag gives qualitatively account for this linear dependence. The period of the pattern λ is found to vary with viscosity v, ω = 2πf, D, and B according to the law λ/D ∼ (B/D)0.5(BωD/v)−0.21. The dynamics of pattern formation exhibits several scenarii, depending on the initial bead distribution, as well as several characteristic time scales. We review and discuss possible mechanisms of pattern formation reported in literature and proposed for similar phenomena observed in the frame of rheology of suspensions and acoustic streaming flows.

Mots clés: Vibrations; Fluid oscillations; Two-phase flow; Viscosity; Rheology

Domaines: Matériaux

Régis Wunenburger, V. Carrier, Yves Garrabos. Periodic order induced by horizontal vibrations in a two-dimensional assembly of heavy beads in water. Physics of Fluids, 2002, 14 (7), 2350 (10 p.). ⟨10.1063/1.1483842⟩. ⟨hal-00719656⟩