Origin of non-Gaussian velocity distributions in steady-state sedimentation
Origin of non-Gaussian velocity distributions in steady-state sedimentation
复制标题
稳态沉积中非高斯速度分布的起源
DOI：
10.1209/epl/i2003-10045-y
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发表时间：
2004
期刊：
影响因子：
1.8
通讯作者：
T. Ala‐Nissila
中科院分区：
文献类型：
--
作者：
E. Kuusela;J. Lahtinen;T. Ala‐Nissila
我们研究了非布朗粒子在稳态沉降过程中的沉降动力学在现实条件下通过计算机模拟。结果表明，平行于重力方向的速度涨落随颗粒体积分数Φ的变化而系统地变化。对于稀体系，它们的分布函数具有非高斯形式，在向下速度的方向上具有延伸的尾部，而对于稠密体系，情况相反。在Φ = 0.05的中间区域，涨落是高斯型的。我们表明，这些分布可以理解的沉降速度和它的波动的依赖性上的局部密度周围的每个粒子。
We study the settling dynamics of non-Brownian particles during steady-state sedimentation under realistic conditions by computer simulations. We show that the velocity fluctuations parallel to gravity change systematically with the particle volume fraction Φ. For dilute systems, their distribution function has a non-Gaussian form, with an extended tail in the direction of the downward velocity, while for dense systems the situation is the opposite. In the intermediate regime at Φ ≈ 0.05 the fluctuations are Gaussian. We show that these distributions can be understood from the dependence of the settling velocity and its fluctuations on the local density around each particle.