Empirical model for Wake Induced Vibrations frequency response of cylinder with low mass ratio
Empirical model for Wake Induced Vibrations frequency response of cylinder with low mass ratio
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DOI：
10.1016/j.oceaneng.2019.106746
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发表时间：
2020
影响因子：
5
通讯作者：
S. Hong;Huang Weiping-;Chang Shuang
中科院分区：
文献类型：
--
作者：
S. Hong;Huang Weiping-;Chang Shuang
采用数值模拟和实验相结合的方法研究了串列柔性圆柱的涡激振动。在质量比为1.08、间距为6D ~ 18 D、折合速度为2.35 ~ 6.71的条件下进行了模拟。结果表明，数值计算结果与响应幅值和频率的实验数据吻合较好。分析了圆柱体的振动幅值、主频率、涡结构和流体作用力的特征。结果表明，上游圆柱体的响应与下游圆柱体的响应有很大的差别。当折合速度超过临界折合速度Vr * 时，上游圆柱和下游圆柱的主频率不再相同。圆柱的折合速度和间距对下游圆柱的尾流激振响应有很大的影响。考虑到这些影响，提出了一种低质量比下游圆柱体WIV频率响应的经验模型，并进行了验证。
The vortex-induced vibrations (VIV) of two flexible circular cylinders in tandem arrangements were studied using numerical simulations and verified by experimental data. Simulations were conducted for a constant mass ratio of 1.08, the spacing ranges of 6Dto 18D, and the reduced velocities of 2.35–6.71. It is shown that the numerical results are in a good agreement with the experimental data of the amplitude and frequency of response. The features of the vibration amplitude, the dominant frequencies, the vortex structures and the fluid force acting on the cylinders are discussed. The results indicate that there is a great difference between the response of the upstream cylinder and that of the downstream cylinder. When the reduced velocity is beyond the critical reduced velocityVr*, the dominant frequencies of the upstream cylinder and the downstream cylinder are no longer the same. And both the reduced velocity and the spacing of the cylinders have a great influence on the wake-induced vibrations (WIV) responses of the downstream cylinder. Considering these influences, an empirical model for WIV frequency response of the downstream cylinder with a low mass ratio was proposed and verified.