Vertical Oscillation of a Bed of Granular Material

Brennen, Christopher E.; Ghosh, Sudeshna; Wassgren, Carl

doi:10.1115/1.2787191

Cited by 37 publications

(22 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As already found experimentally in 1-D [13] and 3-D [19,20] and numerically [13,21], we observe that, at N fixed, the granular medium exhibits (not shown here) a sudden expansion at a critical frequency corresponding to a bifurcation similar to that exhibited by a single ball bouncing on a vibrating plate [13,19]. Moreover, we find that this critical frequency depends on the number of layers, n. When n increases above 0.4, a transition from the 1-D-like behavior to a 3-D one is observed: the expansion at the critical frequency becomes less abrupt and tends to increase regularly with f .…”

supporting

confidence: 70%

Cluster formation, pressure and density measurements in a granular medium fluidized by vibrations

Falcon¹,

Fauve²,

Laroche

1999

Eur. Phys. J. B

View full text Add to dashboard Cite

We report experimental results on the behavior of an ensemble of inelastically colliding particles, excited by a vibrated piston in a vertical cylinder. When the particle number is increased, we observe a transition from a regime where the particles have erratic motions ("granular gas") to a collective behavior where all the particles bounce like a nearly solid body. In the gas-like regime, we measure the density of particles as a function of the altitude and the pressure as a function of the number N of particles. The atmosphere is found to be exponential far enough from the piston, and the "granular temperature", T , dependence on the piston velocity, V , is of the form T ∝ V θ , where θ is a decreasing function of N. This may explain previous conflicting numerical results. PACS. 45.70.-n Granular systems -83.70.Fn Granular solids -05.20.Dd Kinetic theory -83.10.Pp Particle dynamics Granular matter is an interdisciplinary subject, involving soil mechanics (rheology), powder technology [1,2], geophysics (dunes [3], ice floes [4]), astrophysics (planetary rings [5]) and statistical physics of dissipative media [6,7].Recently, considerable attention has been devoted to the role of the inelasticity of the collisions in vibrated granular media, the so-called driven "granular gas" for which the stationary state results from the balance between dissipation by inelastic collisions and power input by external vibrations. While over the years many attempts based on kinetic theory [8][9][10][11] have been made to describe such dissipative granular gases, no agreement has been found so far both with experiments [12,13] and numerical simulations [13][14][15], for the dependence of the "granular temperature" with the parameters of vibration [16][17][18]. The aim of this study was to guess possible gas-like state equations for such dissipative granular gas and to observe new kinetic behaviors which trace back to the inelasticity of collisions.We report an experimental study of a "gas" of inelastically colliding particles, excited by vertical vibrations. When the vibration is strong enough and the number of particles is low enough, the particles display ballistic motion between successive collisions like molecules in a gas (see Fig. 1a). At constant external driving, we show that the pressure passes through a maximum for a critical a e-mail: falcon@lps.ens.fr b a Fig. 1. Transition from a dissipative granular gas to a dense cluster: (a) N = 480; (b) N = 1920, respectively corresponding to roughly 1 and 4 particle layers at rest. The parameters of vibration are f = 20 Hz and A = 40 mm. The driving piston is at the bottom (not visible), the inner diameter of the tube being 52 mm.number of particles before decreasing for large N . We also measure density profiles and extract granular temperature from them. When the density of the medium is increased, the gas-like state is no longer stable but displays the formation of a dense cluster bouncing like a nearly solid body (see Fig. 1b).

show abstract

supporting

confidence: 70%

Cluster formation, pressure and density measurements in a granular medium fluidized by vibrations

Falcon¹,

Fauve²,

Laroche

1999

Eur. Phys. J. B

View full text Add to dashboard Cite

show abstract

“…As already found experimentally in 1-D [3] and 3-D [16,17] and numerically [3,18], we observe that, at N fixed, the granular medium exhibits (see Fig. 4a) a sudden expansion at a critical frequency corresponding to a bifurcation similar to that exhibited by a single ball bouncing on a vibrating plate [3,16].…”

Section: Volume Measurementssupporting

confidence: 61%

“…4a) a sudden expansion at a critical frequency corresponding to a bifurcation similar to that exhibited by a single ball bouncing on a vibrating plate [3,16]. Moreover, Fig.…”

Section: Volume Measurementsmentioning

confidence: 94%

Experimental Study of a Granular Gas Fluidized by Vibrations

Falcon¹,

Fauve²,

Laroche

2001

Granular Gases

View full text Add to dashboard Cite

Abstract. We report experimental results on the behavior of an ensemble of inelastically colliding particles, excited by a vibrated piston in a vertical cylinder. When the particle number is increased, we observe a transition from a regime where the particles have erratic motions (granular "gas") to a collective behavior where all the particles bounce like a nearly solid body. In the gaslike regime, we measure the pressure at constant volume, and the bed expansion at constant external pressure, as a function of the number N of particles. We also measure the density of particles as a function of the altitude, and find that the "atmosphere" is exponential far enough from the piston. From these three independent measurements, we determine a "state equation" between pressure, volume, particle number and the vibration amplitude and frequency.

show abstract

“…In the full fluidization regime, there are no permanent contacts between particles and the system behaves as a dissipative gas [8]. Particle bed reactors are sometimes fluidized by this method instead of upward gas flow ( [9]). When particle accelerations remain below the gravitational acceleration, the system keeps its static nature and the vibrational energy propagates through a rather compact network of interparticle contacts.…”

Section: Introductionmentioning

confidence: 99%

Vibrational dynamics of confined granular materials

et al. 2006

View full text Add to dashboard Cite

By means of two-dimensional contact dynamics simulations, we analyze the vibrational dynamics of a confined granular layer in response to harmonic forcing. We use irregular polygonal grains allowing for strong variability of solid fraction. The system involves a jammed state separating passive (loading) and active (unloading) states. We show that an approximate expression of the packing resistance force as a function of the displacement of the free retaining wall from the jamming position provides a good description of the dynamics. We study in detail the scaling of displacements and velocities with loading parameters. In particular, we find that, for a wide range of frequencies, the data collapse by scaling the displacements with the inverse square of frequency, the inverse of the force amplitude and the square of gravity. Interestingly, compaction occurs during the extension of the packing, followed by decompaction in the contraction phase. We show that the mean compaction rate increases linearly with frequency up to a characteristic frequency and then it declines in inverse proportion to frequency. The characteristic frequency is interpreted in terms of the time required for the relaxation of the packing through collective grain rearrangements between two equilibrium states.

show abstract

Vertical Oscillation of a Bed of Granular Material

Cited by 37 publications

References 9 publications

Cluster formation, pressure and density measurements in a granular medium fluidized by vibrations

Cluster formation, pressure and density measurements in a granular medium fluidized by vibrations

Experimental Study of a Granular Gas Fluidized by Vibrations

Vibrational dynamics of confined granular materials

Contact Info

Product

Resources

About