Experimental study of particle shape dependence of avalanches inside a rotating drum
Experimental study of particle shape dependence of avalanches inside a rotating drum
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DOI：
10.1051/epjconf/202124906001
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发表时间：
2021
影响因子：
--
通讯作者：
Jian Chen;D. Krengel;H. Matuttis
中科院分区：
文献类型：
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作者：
Jian Chen;D. Krengel;H. Matuttis
研究了半满转鼓内球形和非球形颗粒的雪崩现象。通过图像分析获得了粒子集合体重心的时间序列，并分析了它们的单边振幅（SSA）谱。这个新的指标的频谱特征原来是特征的雪崩，在低频范围内的峰值和高频分量的衰减率的存在。SSA谱在非球形颗粒的堆积中有一个峰，而在球形颗粒中没有峰。高频部分的特征在于幂律衰减1/fa（a > 0）。1/ f -衰变仅见于球形粒子。对于有角颗粒的堆积，指数显著偏离a = 1。由于1/ f谱通常与自组织临界性相关，因此动力学具有标度不变性，因此我们可以得出结论，颗粒雪崩不存在标度不变结构。考虑到颗粒数量少和凸颗粒形状的规则性，本研究中揭示的光谱特征可用于验证颗粒模拟。
We investigate the avalanches of spherical and non-spherical granular particles inside half-filled rotating drums. The time series of the center of gravity of the particle assemblies are obtained via image analysis and their single-sided amplitude (SSA) spectra are analyzed. The spectra features of this new indicator turn out to be characteristic for the avalanches, in terms of the existence of peaks in the low-frequency range and the decay rate of high frequency components. The SSA spectrum has a peak for the packings of non-spherical particles but not for the spherical particles. The high frequency part is characterized by a power law decay 1/ f a (a > 0) . A 1/ f -decay is found only for the spherical particles. For the packings of cornered particles, the exponents significantly deviate from a = 1. As 1/ f spectra are often associated with self-organized criticality and therefore a scale invariance of the dynamics, we may conclude that there is no scale-invariant structure for granular avalanches. Considering the small number of particles and the regularity of convex particle shapes being used, the spectral features revealed in this study could be utilized for validating particle simulations.