We present a micro-gravity experimental study of intermediate number density vibro-fluidized inelastic spheres in a rectangular container.Local velocity distributions are investigated,and are found to deviate measurab...We present a micro-gravity experimental study of intermediate number density vibro-fluidized inelastic spheres in a rectangular container.Local velocity distributions are investigated,and are found to deviate measurably from a symmetric distribution for the velocity component of the vibrating direction when dividing particles along the vibration direction into several bins.This feature does not exist in the molecular gas.We further study the hydrodynamic profiles of pressures p and temperatures T in positive and negative components,such as p+y and p-y and T+y and T-y,in accordance with the sign of velocity components of the vibrating direction.Along vibration direction,granular media are found to be not only inhomogeneous and anisotropic,but also different greatly in positive and negative components.Energy equipartition breaks down in this case.展开更多
A 3-D molecular dynamics simulation of a bi-disperse vibro-fluidized granular gas in a cyclic three-compartment cell is performed.A cluster of particles is randomly found in one of the compartments.Lohse's flux mo...A 3-D molecular dynamics simulation of a bi-disperse vibro-fluidized granular gas in a cyclic three-compartment cell is performed.A cluster of particles is randomly found in one of the compartments.Lohse's flux model is modified to incorporate inelastic particle-boundary colBsions.This model predicts that periodically there is clustering in each compartment.It is then found that if the model is further modified to incorporate Gaussian white noise,it correctly predicts the non-sequential clustering behavior confirming that there is no chaotic behavior.展开更多
The clustering behavior of a mono-disperse granular gas is experimentally studied in an asymmetric two-compartment setup. Unlike the random clustering in either compartment in the case of symmetric configuration when ...The clustering behavior of a mono-disperse granular gas is experimentally studied in an asymmetric two-compartment setup. Unlike the random clustering in either compartment in the case of symmetric configuration when lowering the shaking strength to below a critical value, the directed clustering is observed, which corresponds to an imperfect pitchfork bifurcation. Numerical solutions of the flux equation using a modified simple flux function show qualitative agreements with the experimental results. The potential application of this asymmetric structure is discussed.展开更多
基金Supported by the Knowledge Innovation Project of the Chinese Academy of Sciences under Grant No KJCX2-YW-L08the National Natural Science Foundation of China under Grant No 10720101074 and 11034010the Special Fund for Earthquake Research of China under Grant No 201208011,and CNRS,CNES Special Funds.
文摘We present a micro-gravity experimental study of intermediate number density vibro-fluidized inelastic spheres in a rectangular container.Local velocity distributions are investigated,and are found to deviate measurably from a symmetric distribution for the velocity component of the vibrating direction when dividing particles along the vibration direction into several bins.This feature does not exist in the molecular gas.We further study the hydrodynamic profiles of pressures p and temperatures T in positive and negative components,such as p+y and p-y and T+y and T-y,in accordance with the sign of velocity components of the vibrating direction.Along vibration direction,granular media are found to be not only inhomogeneous and anisotropic,but also different greatly in positive and negative components.Energy equipartition breaks down in this case.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10720101074 and 10874209the Knowledge Innovation Program of Chinese Academy of Sciences under Grant No KJCX2-YW-L08,CSSAR and CNES.
文摘A 3-D molecular dynamics simulation of a bi-disperse vibro-fluidized granular gas in a cyclic three-compartment cell is performed.A cluster of particles is randomly found in one of the compartments.Lohse's flux model is modified to incorporate inelastic particle-boundary colBsions.This model predicts that periodically there is clustering in each compartment.It is then found that if the model is further modified to incorporate Gaussian white noise,it correctly predicts the non-sequential clustering behavior confirming that there is no chaotic behavior.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11034010 and 11274354)the Chinese Academy of Sciences "Strategic Priority Research Program - SJ-10" (Grant No. XDA04020200)the Special Fund for Earthquake Research of China (Grant No. 201208011)
文摘The clustering behavior of a mono-disperse granular gas is experimentally studied in an asymmetric two-compartment setup. Unlike the random clustering in either compartment in the case of symmetric configuration when lowering the shaking strength to below a critical value, the directed clustering is observed, which corresponds to an imperfect pitchfork bifurcation. Numerical solutions of the flux equation using a modified simple flux function show qualitative agreements with the experimental results. The potential application of this asymmetric structure is discussed.
