Collision dynamics of wet solids: Rebound and rotation
Collision dynamics of wet solids: Rebound and rotation
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DOI：
10.1016/j.powtec.2016.12.088
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发表时间：
2017-07
影响因子：
5.2
通讯作者：
B. Buck;Y. Tang;S. Heinrich;Ng Niels Deen;J. Kuipers
中科院分区：
文献类型：
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作者：
B. Buck;Y. Tang;S. Heinrich;Ng Niels Deen;J. Kuipers
粒子碰撞过程中的碰撞动力学和能量耗散是描述粒子过程的基础。然而，对于涉及液体的颗粒过程，仍然缺少这样的知识。因此，本文通过测量颗粒的恢复系数，对颗粒垂直或倾斜撞击湿靶板的回弹行为进行了实验研究。在真实的过程中，碰撞大多与粒子（初始）旋转有关，这使得碰撞动力学比平移能量耗散更复杂。因此，这项工作的重点是分析颗粒旋转及其对法向和切向恢复系数的影响，发现法向恢复系数与颗粒的初始旋转无关，但随着液体层的施加而强烈减小。相反，切向恢复系数强烈依赖于初始旋转。在滚动方向上的初始旋转导致平移切向速度的增加，这是由于旋转能量转换为切向动能的结果。因此，碰撞后初始旋转速度降低。相反，在没有初始旋转的碰撞期间，切向方向上的动能由于摩擦而转化为旋转能。
Knowledge about collision dynamics and energy dissipation during particle collision is fundamental for the description of particulate processes. However, such knowledge is still missing for particulate processes that involve liquids. Therefore, in this work rebound behavior of particles impacting normally or obliquely on a wet target plate is investigated experimentally via measuring the coefficient of restitution. In real processes, collisions are mostly associated with particle (initial) rotation, which makes the collision dynamics more complex than just translational energy dissipation. Thus, a focus of this work is on analysis of particle rotation and its influence on normal and tangential coefficient of restitution.The normal coefficient of restitution was found to be independent of particle initial rotation, but decreases strongly with application of a liquid layer. The tangential coefficient of restitution, on the contrary, is strongly dependent on initial rotation. Initial rotation in direction of rolling leads to an increase of translational tangential velocity, resulting from the conversion of rotational energy to kinetic energy in tangential direction. Accordingly, initial rotational velocity decreases after collision. During collisions without initial rotation, on the contrary, kinetic energy in tangential direction is converted to rotational energy due to friction.