Erosive granular avalanches: a cross confrontation between theory and experiment
Erosive granular avalanches: a cross confrontation between theory and experiment
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侵蚀性粒状雪崩：理论与实验的交叉对抗
DOI：
10.1007/s10035-007-0053-3
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发表时间：
2007
期刊：
影响因子：
2.4
通讯作者：
I. Aranson
中科院分区：
文献类型：
--
作者：
É. Clément;F. Malloggi;B. Andreotti;I. Aranson
介绍了在空气和水下进行的两次实验室规模雪崩实验的结果。在这两种情况下，都观察到一系列孤立的侵蚀/沉积波。在较高的倾角下，我们发现存在长波长横向不稳定性，随后出现粗化和指法模式的出现。虽然实验在空间和时间尺度上存在很大差异，但稳定性图、波长选择和雪崩形态之间的一致性表明了常见的侵蚀/沉积情况。这些实验是在致密颗粒流的“部分流化”模型的框架下进行的理论研究。该模型识别了一系列传播的孤立波，其行为与实验观察相似。横向不稳定的主要原因与雪崩速度对被流捕获的颗粒质量的依赖性有关。
Results on two laboratory scale avalanches experiments taking place both in the air and under-water, are presented. In both cases a family of solitary erosion/deposition waves are observed. At higher inclination angles, we show the existence of a long wavelength transverse instability followed by a coarsening and the onset of a fingering pattern. While the experiments strongly differ by the spatial and time scales, the agreement between the stability diagram, the wavelengths selection and the avalanche morphology suggest a common erosion/deposition scenario. These experiments are studied theoretically in the framework of the “partial fluidization” model of dense granular flows. This model identifies a family of propagating solitary waves displaying a behavior similar to the experimental observation. A primary cause for the transverse instability is related to the dependence of avalanche velocity on the granular mass trapped by the flow.