Purpose

This study aims to explore an active control strategy for attenuation of in-line and transverse flow-induced vibration (FIV) of two tandem-arranged circular cylinders.

Design/methodology/approach

The control system is based on the rotary oscillation of cylinders around their axis, which acts according to the lift coefficient feedback signal. The fluid-solid interaction simulations are performed for two velocity ratios (V_r = 5.5 and 7.5), three spacing ratios (L/D = 3.5, 5.5 and 7.5) and three different control cases. Cases 1 and 2, respectively, deal with the effect of rotary oscillation of front and rear cylinders, while Case 3 considers the effect of applied rotary oscillation to both cylinders.

Findings

The results show that in Case 3, the FIV of both cylinders is perfectly reduced, while in Case 2, only the vibration of rear cylinder is mitigated and no change is observed in the vortex-induced vibration of front cylinder. In Case 1, by rotary oscillation of the front cylinder, depending on the reduced velocity and the spacing ratio values, the transverse oscillation amplitude of the rear cylinder suppresses, remains unchanged and even increases under certain conditions. Hence, at every spacing ratio and reduced velocity, an independent controller system for each cylinder is necessary to guarantee a perfect vibration reduction of front and rear cylinders.

Originality/value

The current manuscript seeks to deploy a type of active rotary oscillating (ARO) controller to attenuate the FIV of two tandem-arranged cylinders placed on elastic supports. Three different cases are considered so as to understand the interaction of these cylinders regarding the rotary oscillation.

中文翻译：

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外加旋转振荡对不同间距比的串联圆柱体 FIV 特性的影响

目的

本研究旨在探索一种主动控制策略，用于衰减两个串联排列的圆柱体的在线和横向流动引起的振动 (FIV)。

设计/方法/方法

控制系统基于气缸围绕其轴线的旋转振荡，根据升力系数反馈信号起作用。流体-固体相互作用仿真两个速度比进行（V_ - [R = 5.5和7.5），三个间距比（L / d = 3.5，5.5和7.5）和三个不同的控制例。案例 1 和案例 2 分别处理前后气缸旋转振荡的影响，而案例 3 考虑了对两个气缸施加旋转振荡的影响。

发现

结果表明，在案例 3 中，两个气缸的 FIV 都得到了完美的降低，而在案例 2 中，只有后气缸的振动得到了缓解，而前气缸的涡激振动没有观察到变化。在案例1中，通过前缸的旋转振荡，根据降低的速度和间距比值，后缸的横向振荡幅度被抑制，在一定条件下保持不变甚至增加。因此，在每个间距比和降低的速度下，每个气缸都需要一个独立的控制器系统，以保证前后气缸的完美减振。

原创性/价值

目前的手稿试图部署一种主动旋转振荡 (ARO) 控制器来衰减放置在弹性支撑上的两个串联排列的圆柱体的 FIV。考虑了三种不同的情况，以便了解这些圆柱体在旋转振荡方面的相互作用。