Collapses of two-dimensional granular columns.
Collapses of two-dimensional granular columns.
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DOI：
10.1103/physreve.72.041301
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发表时间：
2005-10
期刊：
影响因子：
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通讯作者：
G. Lube;H. Huppert;R. Sparks;A. Freundt
中科院分区：
文献类型：
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作者：
G. Lube;H. Huppert;R. Sparks;A. Freundt
第一个详细的定量观察二维崩溃的颗粒柱沿着水平通道的各种材料。连同补充研究的轴对称的情况下，我们得出结论，颗粒崩溃的普遍接受的方法，这是高度依赖于摩擦参数，不描述的主要流动现象。该运动在大约1.8处分为两个主流态，其中纵横比a = hi/di，hi和di是柱的初始高度和宽度。我们描述的崩溃的细节，强调的顺序发生的主要蔓延，然后是最终的雪崩阶段。对于低a制度，a 1.8，我们确定几乎所有的崩溃细节，包括作为时间函数的流动前沿的位置，定位时间，自相似的最终轮廓，特别是它们的最大垂直和水平延伸，在扩展阶段建立，可以用初始几何参数表示，但与基底摩擦和内摩擦无关参数
The first detailed quantitative observations of the two-dimensional collapse of a granular column along a horizontal channel are presented for a variety of materials. Together with the complementary study for the axisymmetric situation, we conclude that for granular collapses the generally accepted approaches, that are highly dependent on frictional parameters, do not describe the main flow phenomena. The motion divides in two main flow regimes at a approximately 1.8, where the aspect ratio a = hi/di and hi and di are the initial height and width of the column. We describe the details of collapse by emphasizing the sequential occurrence of a main spreading followed by a final avalanching phase. For the low a regime, a 1.8, we determine that nearly all details of the collapse, including the position of the flow front as a function of time, the emplacement time, the self-similar final profiles, and especially their maximum vertical and horizontal extension, are established during the spreading phase and can be expressed in terms of the initial geometrical parameters but are independent of basal and internal friction parameters.