1/f noise on the brink of wet granular melting

Kai Huang

doi:10.1088/1367-2630/17/8/083055

Abstract

The collective behavior of a two-dimensional wet granular cluster under horizontal swirling motions is investigated experimentally. Depending on the balance between the energy injection and dissipation, the cluster evolves into various nonequilibrium stationary states with strong internal structure fluctuations with time. Quantitative characterizations of the fluctuations with the bond orientational order parameter reveal power spectra of the form with the exponent α closely related to the stationary states of the system. In particular, type of noise with emerges as melting starts from the free surface of the cluster, suggesting the possibility of using noise as an indicator for phase transitions in systems driven far from thermodynamic equilibrium.

Highlights

27 August 2015Depending on the balance between the energy injection and licence
1 f noise is a class of signal exhibiting power spectrum f a with exponent a ~ -1, typically in the range -1.4 < a < -0.8 [1]
I investigate the self-organization of a two-dimensional wet granular cluster under horizontal swirling motion, and use the percentage of particles in a local hexagonal packing to characterize the internal structure fluctuations with time

Summary

27 August 2015

Depending on the balance between the energy injection and licence. Dissipation, the cluster evolves into various nonequilibrium stationary states with strong internal. Any further distribution of this work must maintain structure fluctuations with time. Quantitative characterizations of the fluctuations with the bond attribution to the author(s) and the title of orientational order parameter q6 reveal power spectra of the form f a with the exponent α closely the work, journal citation related to the stationary states of the system. 1 f type of noise with a » -1 emerges as and DOI. Melting starts from the free surface of the cluster, suggesting the possibility of using 1 f noise as an indicator for phase transitions in systems driven far from thermodynamic equilibrium

Introduction

Methods

Nonequilibrium stationary states

Power spectrum of internal structure fluctuations

Conclusions