1 State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2 Key Laboratory of Soft Matter Physics, Beijing National Laboratory for Condense Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China

The free path of a vibro-fluidized two-dimensional (2D) inelastic granular gas confined in a rectangular box is investigated by 2D event-driven molecular simulation. By tracking particles in the simulation, we analyze the local free path. The probability distribution of the free path shows a high tail deviating from the exponential prediction. The anisotropy of the free path is found when we separate the free path to x and y components. The probability distribution of y component is exponential, while x component has a high tail. The probability distribution of angle between the relative velocity and the unit vector joined two particle centers deviates from the distribution of two random vectors, indicating the existence of the dynamic heterogeneities in our system. We explain these results by resorting to the kinetic theory with two-peak velocity distribution. The kinetic theory agrees well with the simulation result.

(Granular flow: mixing, segregation and stratification)

Fund:

Project supported by the National Basic Research Program of China (Grant No. 2012CB215003), the National Natural Science Foundation of China (Grant No. 91334204), the Fund from the Chinese Academy of Sciences (Grant No. XDA07080100), and China Postdoctoral Science Foundation (Grant No. 2014M561071).

Yifeng Mei(梅一枫), Yanpei Chen(陈延佩), Wei Wang(王维), Meiying Hou(厚美瑛) The anisotropy of free path in a vibro-fluidized granular gas 2016 Chin. Phys. B 25 084501

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