Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory, Pune 411008, India and Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
Pfizer Inc., Groton, Connecticut 06340, USA.
Phys Rev E. 2019 Jul;100(1-1):012901. doi: 10.1103/PhysRevE.100.012901.
We show that the interparticle friction coefficient significantly influences the flow and jamming behavior of granular materials exiting through the orifice of a two-dimensional silo in the presence of another orifice located in its vicinity. The fluctuations emanating from a continuous flow through a larger orifice results in an intermittent flow through the smaller orifice consisting of sequential jamming and flowing events. The mean time duration of jammed and flow events, respectively, increase and decrease monotonically with increasing interparticle friction coefficient. The frequency of unjamming instances (n_{u}), however, shows a nonmonotonic behavior comprising an increase followed by a decrease with increasing friction coefficient. The decrease on either side of the maximum, then, represents a system moving progressively towards a permanently jammed or a permanently flowing state. The overall behavior shows a systematic dependence on the interorifice distance, which determines the strength of the fluctuations reaching the smaller orifice leading to unjamming instances. The probability distributions of jamming and flowing times are nearly similar for different combinations of friction coefficients and interorifice distances studied and, respectively, exhibit exponential and power-law tails.
我们表明，颗粒物质在二维筒仓的一个孔附近存在另一个孔的情况下，颗粒间摩擦系数会显著影响其通过孔的流动和堵塞行为。从较大孔连续流动产生的波动会导致较小孔间歇性流动，其中包括连续堵塞和流动事件。堵塞和流动事件的平均持续时间分别随颗粒间摩擦系数的增加而单调增加和减少。然而，解堵塞实例的频率（n_{u}）表现出非单调行为，包括随摩擦系数增加而先增加后减少。最大系数两侧的减少，则表示系统逐渐向永久堵塞或永久流动状态移动。整体行为表现出与中孔距离的系统依赖性，这决定了到达较小孔的波动强度，从而导致解堵塞实例。对于研究的不同摩擦系数和中孔距离组合，堵塞和流动时间的概率分布几乎相似，分别表现出指数和幂律尾部。
