Viscoelastic fluid-structure interactions between a flexible cylinder and wormlike micelle solution
Viscoelastic fluid-structure interactions between a flexible cylinder and wormlike micelle solution
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DOI：
10.1103/physrevfluids.3.063301
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发表时间：
2018-06-11
影响因子：
2.7
通讯作者：
Rothstein, Jonathan P.
中科院分区：
文献类型：
--
作者：
Dey, Anita A.;Modarres-Sadeghi, Yahya;Rothstein, Jonathan P.
众所周知，当柔性或柔性安装的结构垂直于牛顿流体的流动放置时，由于在高雷诺数下分离的涡流的脱落，它可以振荡。与牛顿流体不同，粘弹性流体的流动即使在无穷小的雷诺数下也会变得不稳定，这是由于在大的魏森伯格数下可能发生的纯弹性流动不稳定性。最近的工作表明，这些弹性流动不稳定性可以驱动柔性片材的运动。由弹性流动不稳定性施加在结构上的波动流体力可以导致振荡结构运动与流体流动中的应力状态之间的耦合。本文研究了粘弹性蠕虫状胶束溶液绕柔性圆柱的流动。流场的时间变化和流体中的应力状态显示使用粒子图像跟踪和流致双折射图像的组合。给出了在一定流速范围内柔性圆柱的静态和动态响应。研究结构运动的非线性动力学，以更好地理解所观察到的从对称到非对称的结构变形和振动行为的转变。
It is well known that when a flexible or flexibly mounted structure is placed perpendicular to the flow of a Newtonian fluid, it can oscillate due to the shedding of separated vortices at high Reynolds numbers. Unlike Newtonian fluids, the flow of viscoelastic fluids can become unstable even at infinitesimal Reynolds numbers due to a purely elastic flow instability that can occur at large Weissenberg numbers. Recent work has shown that these elastic flow instabilities can drive the motion of flexible sheets. The fluctuating fluid forces exerted on the structure from the elastic flow instabilities can lead to a coupling between an oscillatory structural motion and the state of stress in the fluid flow. In this paper, we present the results of an investigation into the flow of a viscoelastic wormlike micelle solution past a flexible circular cylinder. The time variation of the flow field and the state of stress in the fluid are shown using a combination of particle image tracking and flow-induced birefringence images. The static and dynamic responses of the flexible cylinder are presented for a range of flow velocities. The nonlinear dynamics of the structural motion is studied to better understand an observed transition from a symmetric to an asymmetric structural deformation and oscillation behavior.