The dynamics of granular flow from a silo with two symmetric openings
The dynamics of granular flow from a silo with two symmetric openings
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DOI：
10.1098/rspa.2018.0462
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发表时间：
2019-01
期刊：
影响因子：
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通讯作者：
L. Fullard;E. Breard;C. Davies;A. Godfrey;M. Fukuoka;A. Wade;J. Dufek;G. Lube
中科院分区：
文献类型：
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作者：
L. Fullard;E. Breard;C. Davies;A. Godfrey;M. Fukuoka;A. Wade;J. Dufek;G. Lube
使用粒子图像测速 (PIV)、流量测量和离散元建模 (DEM) 研究具有两个对称放置的出口的矩形筒仓中颗粒流的动力学。使用高速摄像机记录芥菜籽在有机玻璃筒仓中的流动，并使用 PIV 分析生成的图像帧，以获得速度、速度散度和剪切率图。当两个开口之间的距离 L 变化时，可以观察到流动结构的变化。质量流量在零开度分离时达到最大值，随着 L 的增加而减小；然后它达到最小值，然后上升到接近孤立（非相互作用）开口的两倍的均衡率。使用苋菜和筛过的沙重复流速实验，观察到类似的行为。尽管这一结果与最近的一些 DEM 和筒仓系统中的物理实验形成对比，但这种效应已在类似系统中报告：通过两扇门从房间疏散行人。我们的实验结果使用 DEM 进行了重复，我们表明颗粒间摩擦控制着流速行为，并解释了文献结果中的差异。
The dynamics of granular flow in a rectangular silo with two symmetrically placed exit openings is investigated using particle image velocimetry (PIV), flow rate measurements and discrete element modelling (DEM). The flow of mustard seeds in a Perspex silo is recorded using a high-speed camera and the resulting image frames are analysed using PIV to obtain velocity, velocity divergence and shear rate plots. A change in flow structure is observed as the distance L between the two openings is varied. The mass flow rate is shown to be at a maximum at zero opening separation, decreasing as L is increased; it then reaches a minimum before rising to an equilibrium rate close to two times that of an isolated (non-interacting) opening. The flow rate experiment is repeated using amaranth and screened sand and similar behaviour is observed. Although this result is in contrast with some recent DEM and physical experiments in silo systems, this effect has been reported in an analogous system: the evacuation of pedestrians from a room through two doors. Our experimental results are replicated using DEM and we show that inter-particle friction controls the flow rate behaviour and explains the discrepancies in the literature results.