粒子形状如何影响工业和地球物理流中的颗粒分离
Fernando David Cúñez1, Div Patel1,2, Rachel C Glade1,2
1Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627.
概括
颗粒形状在干燥和湿流中显著影响颗粒分离,根据流量条件和颗粒成分不同,改变颗粒分离动态. 这项研究揭示了相互竞争的分离模式,不仅仅由颗粒大小控制.
科学领域:
- 颗粒状材料的物理学 颗粒状材料的物理学
- 流体动力学 流体动力学
- 地质物理的流动.
背景情况:
- 颗粒分离,即根据物理特征分离颗粒,是工业和地质物理流程中常见的现象.
- 虽然大小诱导的分离是众所周知的,但颗粒形状对分离的影响在很大程度上仍未被探索.
- 了解隔离对于在水泥混合,制药,食品生产和地质物理过程 (如山体滑坡和碎片流) 中的应用至关重要.
研究的目的:
- 在干燥和潮湿的流量条件下,以数值方式研究粒度形状对颗粒分离的影响.
- 为了比较含有球体和立方体的混合物中的分离模式与含有球体和立方体的混合物.
- 为了确定流体-颗粒相互作用如何影响剪切驱动流程中的形状诱导分离.
主要方法:
- 使用旋转鼓进行了数值实验,以模拟干燥,双分散的颗粒流.
- 模拟剪切驱动的合流体颗粒流,模仿河床动力学,进行了分析潮湿条件.
- 分析了球体和球体与立方体的混合物,以分离粒状形状的影响.
主要成果:
- 在干流中,立方颗粒的存在降低了与只有球体的混合物相比的分离水平,这与基于尺寸比率的预期相反.
- 小粒的移动性 (球形与立方形) 影响了分离水平,表明了形状依赖的动态.
- 在湿流中,立方颗粒增加了分离,而流体阻力效应与干流相比,显著改变了分离趋势.
结论:
- 颗粒形状对颗粒分离具有显著的,独立的控制作用,与颗粒大小的影响不同.
- 在干燥与湿的颗粒流中出现相互竞争的分离模式,突出显示了间隙流体的关键作用.
- 这些发现对管理工业颗粒过程和理解地质物理流动行为有广泛的影响.
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