This study aimed to investigate the dispersion pattern of aluminum dust with different particle sizes in 20 L vessels by numerical simulations. Using coupled Eulerian and Lagrangian methods, the system of Navier–Stokes equations and DPM momentum balance equations were solved to obtain the dispersion process of aluminum dust with different particle sizes (25, 38, 45, 60, and 75 μm). A standard deviation of particle concentration (S) was proposed to characterize dispersity of dust; the smaller S is, the better the dispersity of dust is. On the basis of S, after the sample reached uniform distribution, the dust with large particle size could maintain uniform dispersion for a certain time period. By contrast, the dust with small particle size, which was more affected by the central turbulence than large dust particles, had difficulty in maintaining uniform dispersion. In addition, the use of rebound nozzles for dust dispersion led to a large turbulence intensity gradient, which significantly influenced the dust dispersion process, especially on the small particle sizes. A large amount of dust was concentrated in the near-wall region, resulting in the concentration of dust in the center of the chamber being lower than expected.

中文翻译：

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基于数值模拟的粒径对铝粉分散的影响

本研究旨在通过数值模拟研究不同粒径的铝尘在20 L容器中的分散模式。采用欧拉和拉格朗日耦合方法，求解Navier-Stokes方程组和DPM动量平衡方程组，得到不同粒径（25、38、45、60和75μm）铝粉的分散过程。提出用颗粒浓度（S）的标准差来表征粉尘的分散性； S越小，粉尘的分散性越好。以S为基础，样品达到均匀分布后，大粒径粉尘能在一定时间内保持均匀分散。相比之下，小粒径粉尘比大粉尘颗粒更容易受到中心湍流的影响，难以保持均匀分散。此外，使用回弹喷嘴进行粉尘分散会导致较大的湍流强度梯度，这对粉尘分散过程产生显着影响，尤其是对于小粒径的粉尘分散过程。大量粉尘集中在近壁区域，导致试验室中心粉尘浓度低于预期。