Preferential concentration and settling of heavy particles in homogeneous turbulence
Preferential concentration and settling of heavy particles in homogeneous turbulence
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DOI：
10.1063/1.4774339
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发表时间：
2013-01
影响因子：
4.6
通讯作者：
A. Dejoan;R. Monchaux
中科院分区：
文献类型：
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作者：
A. Dejoan;R. Monchaux
Voronoi 图用于分析均匀湍流中重颗粒沉降的单向耦合直接数值模拟数据。分析了惯性粒子的优先集中和聚集，以获得更大范围的粒子斯托克斯和劳斯数。优先浓度对沉降速度增强的影响通过以局部浓度为条件的颗粒和流场量的统计来解决。虽然发现重力对优先集中的全局特征几乎没有影响，但条件统计结果对重力效应产生的流场进行了精细的优先采样。这种优先采样表明，除了下降流体速度的贡献之外，下降流体加速度进一步增加了沉降速度。这种效应无法从粒子浓度场的全局估计中检测到。还提供了 Voronoi 单元的 2D 分析......
Voronoi diagrams are used to analyze one-way coupling direct numerical simulation data of heavy particles settling in homogeneous turbulence. Preferential concentration and clustering of the inertial particles are analyzed for an extended range of particle Stokes and Rouse numbers. Influence of preferential concentration on the settling velocity enhancement is addressed from statistics of particle and flow field quantities conditioned on the local concentration. While gravity is found to have almost no influence on the global characteristics of preferential concentration, the conditional statistics bring out a refined preferential sampling of the flow field resulting from the gravitational effects. This preferential sampling shows that beside the descending fluid velocity contribution, the settling velocity is further increased by the descending fluid acceleration. This effect cannot be detected from global estimations of the particle concentration field. A 2D analysis of the Voronoi cells is also present...