Particle concentration in homogeneous shear turbulence simulated via Lagrangian and equilibrium Eulerian approaches
Particle concentration in homogeneous shear turbulence simulated via Lagrangian and equilibrium Eulerian approaches
复制标题
通过拉格朗日和平衡欧拉方法模拟均匀剪切湍流中的颗粒浓度
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
S. Balachandar
中科院分区：
文献类型：
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作者：
B. Shotorban;S. Balachandar
采用直接数值模拟的方法研究了含颗粒均匀剪切湍流中的颗粒浓度。通过分析不同颗粒时间常数的径向分布函数(RDF)、颗粒数密度的概率密度函数(PDF)、颗粒拉格朗日速度的自相关以及颗粒的湍流扩散系数，对颗粒速度用流体的速度和加速度近似的平衡假设进行了评估。当无量纲粒子时间常数τp*<；0.6时，精确拉格朗日粒子与平衡拉格朗日粒子之间有很好的一致性。在这项工作中，我们还介绍了一种通过计算二维RDF来测量拉格朗日粒子浓度各向异性的新方法。结果表明，沿流向和横流方向的颗粒堆积最多，最少。此外，本文还介绍了一种新的研究方法。
Direct numerical simulation is conducted to study particle concentration in particle-laden homogeneous shear turbulence. The equilibrium assumption in which the velocity of particles is approximated in terms of the velocity and acceleration of the fluid phase is assessed for this flow by analyzing the radial distribution function (RDF), the probability density function (PDF) of the number density of particles, the autocorrelation of particle Lagrangian velocity, and the particle turbulent diffusivity for various particle time constants. A good agreement between exact and equilibrium Lagrangian particles is observed for these statistics when nondimensional particle time constant τp*<0.6. In this work, we also introduce a new methodology for measuring the anisotropy of the Lagrangian particle concentration through calculating two-dimensional RDFs. It is shown that particles are the most and least accumulated in the streamwise and cross-stream directions, respectively. Also, a methodology is introduced to ex...