Refinement of the probability density function model for preferential concentration of aerosol particles in isotropic turbulence
Refinement of the probability density function model for preferential concentration of aerosol particles in isotropic turbulence
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DOI：
10.1063/1.2813044
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发表时间：
2007-11
影响因子：
4.6
通讯作者：
L. I. Zaichik;V. M. Alipchenkov
中科院分区：
文献类型：
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作者：
L. I. Zaichik;V. M. Alipchenkov
本文件的目的有三：（i）改进Zaichik和Alipchenkov [Phys.Fluids 15，1776（2003）]提出的各向同性湍流中优先颗粒浓度的统计模型，（ii）使用改进的模型研究低惯性颗粒的聚集效应，（iii）提出一个预测气溶胶粒子碰撞率的简单模型。该模型是基于一个动力学方程的两点概率密度函数的相对速度分布的颗粒对。由于通过包括应变和旋转速率相关性的时间尺度之间的差异来细化载流流体的湍流速度场的描述，在预测低惯性颗粒的优先浓度方面得到改进。改进后的模型与气溶胶粒子的直接数值模拟结果有更好的一致性。
The purposes of the paper are threefold: (i) to refine the statistical model of preferential particle concentration in isotropic turbulence that was previously proposed by Zaichik and Alipchenkov [Phys. Fluids 15, 1776 (2003)], (ii) to investigate the effect of clustering of low-inertia particles using the refined model, and (iii) to advance a simple model for predicting the collision rate of aerosol particles. The model developed is based on a kinetic equation for the two-point probability density function of the relative velocity distribution of particle pairs. Improvements in predicting the preferential concentration of low-inertia particles are attained due to refining the description of the turbulent velocity field of the carrier fluid by including a difference between the time scales of the of strain and rotation rate correlations. The refined model results in a better agreement with direct numerical simulations for aerosol particles.