Abstract A study is performed numerically to understand the effect of incident turbulence intensity T u (0%–10%) on flow-induced vibration of an isolated elastic cylinder subjected to an axial tubular flow. The cylinder fix-supported at both ends is free to vibrate laterally. Large eddy simulation and the two-way coupled CFD-CSM calculation are employed to capture the characteristics of turbulent flow and fluid–structure interaction, respectively. The calculated root-mean-square (rms) vibration amplitude of the cylinder agrees reasonably well with experimental data at T u = 0 .3%, thus providing a validation for the present numerical code. The dimensionless velocity u ∗ ≡ U ∞ L( ρ f A c /EI) 1∕2 is in the range of 1.52 – 9.67, where U ∞ , ρ f , L, A c and EI are the free-stream velocity, fluid density, length and cross-sectional area of the cylinder and the corresponding flexural rigidity, respectively. The T u is found to produce a pronounced effect on dynamics of the cylinder at u ∗ ≤ 9.67. At u ∗ = 3 . 30 , the vibration amplitude of the cylinder significantly increases with increasing T u from 0 to 10%. Under the same T u range, the onset of cylinder buckling does not depend on T u , though the onset of flutter does. The cylinder buckles at u ∗ = 7 . 92 and T u = 0% and further undergoes flutter instability as T u increases to 1.0%. It is proposed that interactions between the buckled cylinder and the higher-intensity turbulence amplifies the shear layer instability around the cylinder, forming uniform-low-pressure and nonuniform-high-pressure regions around the cylinder. These regions quasi-periodically reposition, thus generating unsteady lateral forces that are responsible for the flutter instability at T u = 1 .0%. It is found that dimensionless rms vibration amplitude A r m s ∗ (= [( A x r m s /D)2 + ( A y r m s /D)2] 1∕2 , where D and the first letter of the subscript denote cylinder diameter and vibration direction, respectively) in flutter scales linearly with the effective velocity u e f f ∗ = u ∗ TF, where turbulence factor TF is introduced to account for the effect of T u .

中文翻译：

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湍流强度对弹性圆柱轴流振动的影响

摘要 进行数值研究以了解入射湍流强度 T u (0%–10%) 对受轴向管状流作用的孤立弹性圆柱体的流致振动的影响。两端固定支撑的气缸可自由横向振动。大涡模拟和双向耦合 CFD-CSM 计算分别用于捕捉湍流和流固耦合的特征。计算出的圆柱体的均方根 (rms) 振动幅度与 T u = 0 .3% 时的实验数据相当吻合，从而为当前数值代码提供了验证。无量纲速度 u ∗ ≡ U ∞ L( ρ f A c /EI) 1∕2 在 1.52 – 9.67 的范围内，其中 U ∞ 、ρ f 、L、A c 和 EI 是自由流速度，流体密度，分别为圆柱体的长度和截面积以及相应的抗弯刚度。发现 T u 在 u ∗ ≤ 9.67 时对气缸的动力学产生显着影响。在 u ∗ = 3 。如图30所示，随着T u 从0％增加到10％，气缸的振动幅度显着增加。在相同的 T u 范围下，虽然颤振的开始取决于 T u ，但圆柱体屈曲的开始不依赖于 T u 。圆柱体在 u ∗ = 7 处弯曲。92 和 T u = 0% 并且随着 T u 增加到 1.0% 进一步经历颤振不稳定。提出了屈曲圆柱体和更高强度湍流之间的相互作用放大了圆柱体周围的剪切层不稳定性，在圆柱体周围形成了均匀低压和非均匀高压区域。这些区域准周期性地重新定位，从而产生不稳定的横向力，导致 T u = 1 .0% 处的颤振不稳定。发现无量纲均方根振幅A rms ∗ (= [( A xrms /D)2 + ( A yrms /D)2 ] 1∕2 ，其中D和下标的第一个字母表示圆柱直径和振动方向，分别）在颤振尺度上与有效速度 ueff ∗ = u ∗ TF 呈线性关系，其中引入湍流因子 TF 来解释 T u 的影响。