弹性支撑圆柱绕流稳定性分析

李新涛; 张伟伟; 蒋跃文; 叶正寅

doi:10.6052/0459-1879-14-307

弹性支撑圆柱绕流稳定性分析

西北工业大学翼型叶栅空气动力学国家级重点实验室, 西安710072

基金项目: 国家自然科学基金(11072199,11172237),教育部“新世纪优秀人才支持计划”(NCET-13-0478)和陕西省“青年科技新星”计划等资助项目.

详细信息

通讯作者:
张伟伟,教授,主要研究方向:非定常空气动力学、气动弹性力学及流动控制.E-mail:aeroelastic@nwpu.edu.cn

中图分类号: V211.3
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出版历程
- 收稿日期: 2014-10-09
- 修回日期: 2015-06-05
- 刊出日期: 2015-09-17

STABILITY ANALYSIS OF FLOW PAST AN ELASTICALLY-SUSPENDED CIRCULAR CYLINDER

National Key Laboratory of Aerodynamic Design and Research, Northwestern Polytechnical University, Xi'an 710072, China

Funds: The project was supported by the National Natural Science Foundation of China (11072199, 11172237), Program for New Century Excellent Talents in University (NCET-13-0478) and the Youth Nova of Science and Technology of Shanxi Province.

摘要

摘要: 基于CFD 技术,采用系统辨识方法,建立了亚临界雷诺数(Re < 47) 下绕圆柱流动的非定常气动力模型(reduced order model, ROM). 耦合结构运动方程和降阶气动力模型,建立了弹性支撑圆柱绕流的稳定性分析模型. 算例分析了亚临界雷诺数下,结构固有频率、质量比等参数以及支撑方式对弹性系统稳定性的影响. 对于单自由度横向支撑圆柱,当结构固有频率趋近流动最不稳定模态频率时,弹性系统会在一定频率范围内失稳,这种现象最低可在Re~20 时出现. 旋转自由度的释放能够进一步降低系统的稳定性,可将临界雷诺数进一步降低至18 左右. ROM 方法不仅具有很高的效率,而且清晰地指出了弹性系统失稳的根本原因:流动模态和结构模态耦合作用导致结构模态失稳所致. 因此,失稳状态下系统振荡频率锁定于结构固有频率. 基于ROM 技术预测的失稳边界与直接CFD/CSD 仿真结果吻合,证明了该方法的正确性和精度.
- 圆柱绕流 /
- 系统辨识 /
- 降阶模型 /
- 涡致振动 /
- 稳定性分析
Abstract: An identification technique is used to construct reduced order models (ROMs) for the cylinder wake flow at subcritical Reynolds numbers (Re <47) using CFD simulation data. ROM-based aeroelastic models are then found by coupling the structural motion equations and ROMs. The impacts of structural frequency, mass ratio and mount style on the instability boundaries are investigated. It is found that self-excited oscillations, accompanied by vortex shedding are possible at Re as low as 20 for one freedom transversely suspended cylinder, as the structural frequency gets close to that of the most unstable mode of flow. The release of rotational freedom could further increase the instability of the coupled system and the critical Re can be reduced to 18. ROM-based method not only has high efficiency but also profoundly shows that the inherent instability of the coupled system is induced by the unstable of the structure mode. Therefore, in the unstable region, the vibration frequency of the coupled system is synchronized with the natural frequency of the cylinder.
- cylinder /
- system identification /
- ROM /
- vortex induced vibration /
- stability analysis

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参考文献(12)

Williamson CHK. Vortex dynamics in the cylinder wake. Annual Review of Fluid Mechanics, 1996, 28(1): 477-539

陈文曲, 任安禄, 李广望. 串列双圆柱绕流下游圆柱两自由度涡致振动研究. 力学学报, 2004, 36(6): 732-738 (Chen Wenqu, Ren Anlu, Li Guangwang. The numerical study of two-degree of freedom vortex-induced vibrations of the downstream cylinder in tandem arrangement. Chinese Journal of Theoretical and Applied Mechanics, 2004, 36(6): 732-738 (in Chinese))

宋芳, 林黎明, 凌国灿. 圆柱涡激振动的结构-尾流振子耦合模型研究. 力学学报, 2010, 42(3): 357-365 (Song Fang, Lin Liming, Lin Guocan. The study of vortex-induced vibrations by computation using coupling model of structure and wake oscillator. Chinese Journal of Theoretical and Applied Mechanics, 2010, 42(3): 357-365 (in Chinese))

王俊高, 付世晓, 许玉旺等. 正弦振荡来流下柔性立管涡激振动发展过程. 力学学报, 2014, 46(2): 173-182 (Wang Jungao, Fu shixiao, Xu yuwang, et al. VIV development process of a flexible cylinder under oscillatory flow. Chinese Journal of Theoretical and Applied Mechanics, 2014, 46(2): 173-182 (in Chinese))

Bearman PW. Circular cylinder wakes and vortex-induced vibrations. Journal of Fluids and Structures, 2011, 27(5): 648-658

Williamson CHK, Govardhan R. Vortex-induced vibrations. Annual Review of Fluid Mechanics, 2004, 36: 413-455

Cossu C, Morino L. On the instability of a spring-mounted circular cylinder in a viscous flow at low Reynolds numbers. Journal of Fluids and Structures, 2000, 14(2): 183-196

Mittal S, Singh S. Vortex-induced vibrations at subcritical Re. Journal of Fluid Mechanics, 2005, 534: 185-194

张伟伟, 叶正寅. 基于非定常气动力辨识技术的气动弹性数值模拟. 航空学报, 2006, 27(4): 579-583 (Zhang Weiwei, Ye Zhengyin. Numerical simulation of aeroelasticity basing on identification technology of unsteady aerodynamic loads. Acta Aeronautica et Astronautica Sinica, 2006, 27(4): 579-583 (in Chinese))

张伟伟, 叶正寅, 杨青. 基于 ROM 技术的阵风响应分析方法. 力学学报, 2008, 40(5): 593-598 (Zhang Weiwei, Ye Zhengyin, Yang Qing. Gust response analysis using CFD-based reduced order models. Chinese Journal of Theoretical and Applied Mechanics, 2008, 40(5): 593-598 (in Chinese))

Cowan TJ, Arena AS, Gupta KK. Accelerating computational fluid dynamics based aeroelastic predictions using system identification. Journal of Aircraft, 2001, 38(1): 81-87

蒋跃文. 基于广义网格的CFD方法及其应用. [博士论文]. 西安:西北工业大学, 2013 (Jiang Yuewen. Numerical solution of Navier-Stokers equations on generalized mesh and its applications. [PhD Thesis]. Xi'an: Northwestern Polytechnical University, 2013 (in Chinese))