Modeling of the Collision Kernel of Monodisperse Particles in Turbulent Flows
Modeling of the Collision Kernel of Monodisperse Particles in Turbulent Flows
复制标题
湍流中单分散粒子碰撞核的建模
DOI：
10.1299/kikaib.73.1307
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
S. Komori
中科院分区：
文献类型：
--
作者：
R. Onishi;S. Komori
湍流中单分散惯性颗粒的碰撞频率受很宽尺度的流体运动控制。最近的研究表明，大尺度的能量涡流主导两个碰撞粒子之间的相对速度（湍流输运效应），而小尺度的耗散涡流可以通过诱导局部不均匀的粒子分布（累积效应），显着提高碰撞频率。在这项研究中，这两种效果分别研究通过直接数值模拟（DNS）的单分散颗粒悬浮在不断发展的湍流。结果表明，现有的模式可以预测湍流输送效应，但不能预测累积效应。利用DNS数据建立了一个新的累积效应模型。最后，一个集成的碰撞核模型，它包括一个现有的模型的湍流传输效应和我们的模型的积累效应，已被开发来预测碰撞频率在任意雷诺数和颗粒惯性。
The collision frequency of monodisperse inertia particles in a turbulent flow is governed by a wide range of scales of flow motion. Recent studies have shown that large-scale energetic eddies dominate the relative velocity between two colliding particles (the turbulent transport effect), whereas small-scale dissipative eddies can enhance the collision frequency significantly by inducing local non-uniform particle distribution (the accumulation effect). In this study, these two effects are separately investigated through direct numerical simulations (DNS) of monodisperse particles suspended in evolving turbulent flows. The data show that the turbulent transport effect can be predicted by existing models but the accumulation effect cannot. A new model for the accumulation effect has been developed by using the DNS data. Finally, an integrated collision kernel model, which consists of an existing model for the turbulent transport effect and our model for the accumulation effect, has been developed to predict the collision frequency at arbitrary Reynolds numbers and particle inertia.