Sessile liquid drops damp vibrating structures
Sessile liquid drops damp vibrating structures
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DOI：
10.1063/5.0055382
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发表时间：
2021-06-01
影响因子：
4.6
通讯作者：
Dickerson, Andrew K.
中科院分区：
文献类型：
--
作者：
Alam, Md Erfanul;Dickerson, Andrew K.
在这项研究中，我们探索了位于毫米悬臂梁上的不同粘度和表面张力的单一液滴的振动阻尼特性。悬臂在其自由端位移 0.6 毫米，即其长度的 6%，并允许自由振动。这种振铃振动会导致液滴变形或晃动，从而通过液滴内的粘性耗散和接触线摩擦来耗散动能。液滴晃动的阻尼取决于粘度、表面张力、液滴尺寸和液滴位置。使用与实验液滴质量相同的固体重量来与液体施加的阻尼进行比较，从而考虑其他阻尼源。研究的最粘性和最不粘性的液滴都没有对悬臂运动产生最大的阻尼。相反，中等粘度的下降可以实现晃动和内部耗散能力的最有效平衡。带有晃动液滴的非常薄的悬臂梁表现出多个主频率并且振动不规律，经常发生相位变化，这对阻尼的量化提出了挑战。最后，我们引入了一个新的无量纲组，旨在合并悬臂下降系统的所有显着变量。
In this study, we explore the vibration damping characteristics of singular liquid drops of varying viscosity and surface tension resting on a millimetric cantilever. Cantilevers are displaced 0.6mm at their free end, 6% their length, and allowed to vibrate freely. Such ringdown vibration causes drops to deform, or slosh, which dissipates kinetic energy via viscous dissipation within the drop and through contact line friction. Damping by drop sloshing is dependent on viscosity, surface tension, drop size, and drop location. A solid weight with the same mass as experimental drops is used to compare against the damping imposed by liquids, thereby accounting for other damping sources. Neither the most viscous nor least viscous drops studied imposed the greatest damping on cantilever motion. Instead, drops of intermediate viscosity strike the most effective balance of sloshing and internal dissipative capacity. Very thin cantilevers with sloshing drops express more than one dominant frequency and vibrate erratically, often shifting phase, presenting a challenge for quantification of damping. Finally, we introduce a new dimensionless group aimed at incorporating all salient variables of our cantilever-drop system.