准二维二元混合颗粒动态循环反转分层的体积效应

Volume effect in the cyclic segregation of quasi two-dimensional binary granular mixture

对垂直振动作用下准二维二元混合颗粒系统的动态循环反转分层现象进行了系统研究,得到了频率与加速度的关系相图,并观测到分层的动态循环反转区域.发现动态循环的反转周期与颗粒总体积的变化有单调递增关系.利用Hong的竞争机制理论对动态循环反转的现象及其体积效应的机理给出了解释.

A systematic study about the cyclic segregation observed experimentally in a vertically vibrated quasi two-dimensional binary granular mixture is reported. The frequency-amplitude phase diagram was obtained,in which the region of cyclic segregation was found. We also measured the period of the cyclic segregation and showed the relationship between the period and total volume of granular mixture. Finally,the competition mechanism of percolation and condensation from Hong’s theory is used to explain the cyclic segregation and volume effect qualitatively.