Nonhomogeneous Sedimentation in Viscoelastic Fluids
Nonhomogeneous Sedimentation in Viscoelastic Fluids
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DOI：
10.1122/1.550030
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发表时间：
1989-05
影响因子：
3.3
通讯作者：
E. Allen;P. Uhlherr
中科院分区：
文献类型：
--
作者：
E. Allen;P. Uhlherr
草图和图表展示了一种新的现象，即在具有小密度差的液固系统中的非均匀沉降。在适度剪切变稀的粘弹性流体中的低雷诺数沉降导致显著的上升液体袋图案，其类似于在逐渐压实的床内的鼓泡（聚集）流化。颗粒浓度的不均匀性随着剪切变稀的增加而变得越来越明显，直到最终颗粒完全不能分散在某些流体中。描述的不均匀性的性质和条件下，它们变得明显的定性讨论。
Sketches and diagrams are presented to demonstrate a new phenomenon of nonhomogeneous sedimentation in liquid‐solid systems with a small density difference. Low Reynolds number sedimentation in moderately shear‐thinning viscoelastic fluids results in a striking pattern of rising liquid pockets, which resemble bubbling (aggregative) fluidization within a progressively compacting bed. Inhomogeneities in particle concentration become increasingly apparent with increasing shear‐thinning, until ultimately particles could not be dispersed at all in some fluids. The nature of the inhomogeneities is described and the conditions under which they become apparent are qualitatively discussed.