On the wake-induced vibration of tandem circular cylinders: the vortex interaction excitation mechanism
On the wake-induced vibration of tandem circular cylinders: the vortex interaction excitation mechanism
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DOI：
10.1017/s0022112010003095
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发表时间：
2010-10-25
影响因子：
3.7
通讯作者：
Meneghini, J. R.
中科院分区：
文献类型：
--
作者：
Assi, G. R. S.;Bearman, P. W.;Meneghini, J. R.
通过实验研究了串列双圆柱的尾流激振机理。典型的涡激振动响应的特征是振幅的积累持续到高折合速度;这与典型的涡激振动（VIV）响应不同，后者发生在有限的共振范围内。我们认为，下游圆柱的WIV是由物体与上游尾迹之间的非定常涡-结构相互作用激发的。相干涡流干扰下游圆柱体引起与运动不同步的流体力波动。位移和流体力之间的有利相位滞后保证了从流到结构的正能量传递维持振荡。如果从上游物体的尾流中去除非定常涡流，则不会激发WIV。在定常剪切流中进行的一个实验被证明是理解作用在下游圆柱体上的流体力的起源的核心。
The mechanism of wake-induced vibrations (WIV) of a pair of cylinders in a tandem arrangement is investigated by experiments. A typical WIV response is characterized by a build-up of amplitude persisting to high reduced velocities; this is different from a typical vortex-induced vibration (VIV) response, which occurs in a limited resonance range. We suggest that WIV of the downstream cylinder is excited by the unsteady vortex-structure interactions between the body and the upstream wake. Coherent vortices interfering with the downstream cylinder induce fluctuations in the fluid force that are not synchronized with the motion. A favourable phase lag between the displacement and the fluid force guarantees that a positive energy transfer from the flow to the structure sustains the oscillations. If the unsteady vortices are removed from the wake of the upstream body then WIV will not be excited. An experiment performed in a steady shear flow turned out to be central to the understanding of the origin of the fluid forces acting on the downstream cylinder.