Dynamic Packing Density Of Granular Mixture Under Vertical Vibration

Particulate material accumulation system has been the focus of the studyin particle physics. For static pile system, Edwards et al proposed a bulkas crucial extensive quantity to describe the system, And the spatialconfiguration and the volume fraction has been studied in detail. However,when the particle system in the external conditions, the evolution of whichthe volume fraction of the few people involved in research. In this paper,the static bulk density on the basis of the findings, the dynamic bulk densityparticle binary mixtures under vibration conditions.We first experimental studied of the evolution of particles in the watersystem and its dynamic volume fraction in a variety of vertical vibration.When the system reached a steady state dynamic, using high-speed camera torecord the volume of the particle system changes over time. We found that:(1) Under-induced vibration conditions by the particle system in, The volumefraction of the dynamic cyclical changes;(2) at a fixed acceleration andchanging the frequency of conditions, Dynamic volume fraction was presentedwith monotonous frequency attenuation;(3) at a fixed frequency while changingthe acceleration condition, Dynamic volume fraction with a monotonicallyincreased relationship between vibration acceleration presented. Stillfurther, Fourier transform analysis we found that: Linear relationship betweenthe driving frequency of the dynamic volume of the power spectrum with theoutside world.We next studied experimentally in different viscosity medium volumefraction of particles in the system dynamic power spectrum. We found that:in different viscosities medium frequency power spectrum of the drive has adifferent response. In aqueous media, the power spectrum and frequency showeda linear relationship; viscosity larger or smaller medium frequency powerspectrum and exhibit non-linear relationship, there have been a half-frequencyexternal vibration frequencies (high viscosity) and two multiplier (air). Themechanism was such that the system produces a high viscosity closer coalescence,and low viscosity so that the system becomes more loose.