Dilute Wet Granulates: Nonequilibrium Dynamics and Structure Formation

Abstract

We investigate a gas of wet granular particles, covered by a thin liquid film. The dynamic evolution is governed by two-particle interactions, which are mainly due to interfacial forces in contrast to dry granular gases. When two wet grains collide, a capillary bridge is formed and stays intact up to a certain distance of withdrawal when the bridge ruptures, dissipating a fixed amount of energy. A freely cooling system is shown to undergo a nonequillibrium dynamic phase transition from a state with mainly single particles and fast cooling to a state with growing aggregates, such that bridge rupture becomes a rare event and cooling is slow. In the early stage of cluster growth, aggregation is a self-similar process with a fractal dimension of the aggregates approximately equal to D_f ~ 2. At later times, a percolating cluster is observed which ultimately absorbs all the particles. The final cluster is compact on large length scales, but fractal with D_f ~ 2 on small length scales.

14 pages, 20 figures

References in corpus (3)

• Dynamics of Freely Cooling Granular Gases
• Cooling and aggregation in wet granulates
• Equation of State of Wet Granular Matter

Cited by in corpus (7)

• Coefficient of restitution for wet particles
• Influence of the liquid film thickness on the coefficient of restitution for wet particles
• Fluid depletion in shear bands
• Kinetic theory for dilute cohesive granular gases with a square well potential
• Stability of freely falling granular streams
• Hydrodynamic instabilities in shear flows of cohesive granular particles
• Arrest of three-dimensional gravity-confined shear flow of wet granular matter