Numerical calculation of vortex-induced vibration of a cylinder structure
CHEN Dongyang1, XIAO Qing2, GU Chaojie1, WANG Guoping3, RUI Xiaoting3
1.College of Electrical, Energy and Power Engineering, Yangzhou University, Yangzhou 225100, China;
2.China Ship Development and Design Center, Wuhan 430064, China;
3.Institue of Launch Dynamics, Nanjing University of Science and Technology, Nanjing 210094, China
摘要为了研究柱体结构的涡激振动特性预测方法，首先基于Van der Pol尾流振子模型建立了弹性支撑单自由度柱体的涡激振动模型。然后基于计算流体力学（CFD）方法、结构动力学理论以及嵌套网格技术，同时考虑弹性支撑柱体来流向和横向振动，建立了柱体结构的涡激振动高保真仿真模型。通过与国外文献实验数据对比，验证了两种模型的准确性。计算结果表明，在低质量比情况下，Van der Pol尾流振子模型在约化速度较小区域计算误差很大，在柱体振幅最大值附近误差较小，基本上可以捕捉到柱体的涡激振动特性，可以用于工程上快速预测柱体结构的涡激振动特性；在低质量比、高质量比以及指定的约化速度范围内，采用CFD方法和嵌套网格技术，可以避免由于柱体振幅较大引起的网格畸变和负网格问题，且可以获得较好的计算精度和详细的流场信息，但计算效率相比Van der Pol尾流振子模型较低。
Abstract：In order to study a prediction method for vortex-induced vibration (VIV) characteristics of a cylinder structure, the VIV model of a single-DOF elastically supported cylinder was established based on Van der Pol wake oscillator model firstly. Then, based on the computational fluid dynamics (CFD) method and the overset mesh technique, considering simultaneously incoming flow direction vibration and transverse one of the elastically supported cylinder, the hi-fi simulation model for VIV of the cylinder structure was established. The simulation results were compared with the test data published in abroad reference to verify the correctness of the two models. The simulation results showed that in cases of low mass ratio, the calculation error of Van der Pol wake oscillator model is very large in fields with a smaller reduction velocity, while this error is smaller in fields near the maximum amplitude of the cylinder to basically capture VIV characteristics of the cylinder, and Van der Pol wake oscillator model can be used to rapidly predict VIV characteristics of cylinder structures in engineering; within ranges of low mass ratio, high mass ratio and specified reduction speed, using CFD method and overset mesh technique can avoid mesh distortion and negative mesh problems caused by larger vibration amplitude of the cylinder, and obtain better calculation accuracy and detailed flow field information, but the calculation efficiency is lower than that of Van der Pol wake oscillator model.
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