Clustering of charged inertial particles in turbulence.
Clustering of charged inertial particles in turbulence.
复制标题
湍流中带电惯性粒子的聚集。
DOI：
10.1103/physrevlett.104.184505
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发表时间：
2010
影响因子：
8.6
通讯作者：
R. Shaw
中科院分区：
文献类型：
--
作者：
Jiang Lu;H. Nordsiek;E. Saw;R. Shaw
对均匀各向同性湍流中带电惯性粒子聚集的全息测量揭示了新的粒子动力学。当粒子带电相同时，库仑排斥引入了一个长度标度，低于该长度标度时，惯性聚集被抑制，使得径向分布函数(RDF)模拟非理想气体的分布函数。结果用Fokker-Planck框架描述，该框架将惯性团簇模拟为包括库仑相互作用的修正扩散-漂移过程。粒子在库仑斥力作用下的末端速度与由有限的粒子惯性引起的流体应变和旋转的不均匀采样所得到的时间平均“漂移”速度之间的平衡很好地预测了RDF中的峰值。得到的RDF的泛函形式与测量结果非常匹配，为粒子聚集的漂移扩散描述提供了支持。
Holographic measurements of the clustering of electrically charged, inertial particles in homogenous and isotropic turbulent flow reveal novel particle dynamics. When particles are identically charged, Coulomb repulsion introduces a length scale below which inertial clustering is suppressed such that the radial distribution function (RDF) mimics that of a nonideal gas. The result is described with a Fokker-Planck framework modeling inertial clustering as a diffusion-drift process modified to include Coulomb interaction. The peak in the RDF is well predicted by the balance between the particle terminal velocity under Coulomb repulsion and a time-averaged "drift" velocity obtained from the nonuniform sampling of fluid strain and rotation due to finite particle inertia. The resulting functional form of the RDF matches the measurements closely, providing support for the drift-diffusion description of particle clustering.