Homogeneous cooling state of a low-density granular flow
Homogeneous cooling state of a low-density granular flow
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DOI：
10.1103/physreve.54.3664
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发表时间：
1996-10-01
影响因子：
2.4
通讯作者：
Cubero, D
中科院分区：
文献类型：
--
作者：
Brey, JJ;RuizMontero, MJ;Cubero, D
用直接模拟蒙特卡罗方法研究了由玻尔兹曼方程描述的光滑球形颗粒流的均匀冷却状态。得到了速度矩和速度分布函数，并与最近得到的近似解析结果进行了比较。讨论了温度随时间变化的麦克斯韦-玻尔兹曼近似的精度。此外，模拟结果表明，均匀密度状态在足够长的波长扰动下是不稳定的，使得整个系统自发形成团簇和空洞。这种不稳定性具有致密流体分子动力学模拟中观察到的聚类不稳定性特征，并通过颗粒流流体动力学模型进行了预测。
The homogeneous cooling state of a granular flow of smooth spherical particles described by the Boltzmann equation is investigated by means of the direct simulation Monte Carlo method. The velocity moments and also the velocity distribution function an obtained and compared with approximate analytical results derived recently. The accuracy of a Maxwell-Boltzmann approximation with a time-dependent temperature is discussed. Besides, the simulations show that the state of uniform density is unstable to long enough wavelength perturbations so that clusters and voids spontaneously form throughout the system. The instability has the characteristic features of the clustering instability which has been observed in molecular dynamics simulations of dense fluids and predicted by hydrodynamic models of granular flows.