How do neighbors affect incipient particle motion in laminar shear flow
How do neighbors affect incipient particle motion in laminar shear flow
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DOI：
10.1063/1.4874604
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发表时间：
2014-05
影响因子：
4.6
通讯作者：
J. R. Agudo;S. Dasilva;A. Wierschem
中科院分区：
文献类型：
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作者：
J. R. Agudo;S. Dasilva;A. Wierschem
我们的实验研究如何相邻的颗粒影响的初始运动的颗粒上定期基板和暴露于层流剪切流。为此，我们确定临界希尔兹数，并确定粒子滚动或滑动。该基板由单层的固定球均匀的大小，有规律地安排在三角形和二次配置。邻近的颗粒通过屏蔽剪切流来影响初始运动，并且一旦它们与颗粒直接接触就可能抑制连续运动。在研究的低颗粒雷诺数，单层上的相邻球体只影响初始颗粒运动，如果他们是接近约3个颗粒直径。直接接触会抑制连续运动，并导致临界护盾数大幅增加。对于相同的珠子，我们发现两个不同的制度的连续运动的发病。取决于基板的几何形状，上游颗粒可能会开始滚动像…
We experimentally study how neighboring particles affect the incipient motion of particles on regular substrates and exposed to a laminar shear flow. To this end, we determine the critical Shields number and determine whether the particle rolls or slides. The substrates consist of a monolayer of fixed spheres of uniform size that are regularly arranged in triangular and quadratic configurations. Neighboring particles influence the incipient motion by shielding to the shear flow and may inhibit continuous motion once they are in direct contact with the particle. At the low particle Reynolds numbers studied, neighboring spheres on the monolayer only affect the incipient particle motion if they are closer than about 3 particle diameters. Direct contact inhibits continuous motion and results in a strong increase of the critical Shields number. For identical beads, we found two different regimes for the onset of continuous motion. Depending on the substrate geometry, the upstream particle may start to roll lik...