Investigation of Vortex Induced Excitation Employing Nonlinear Dynamics and Chaos Theory

利用非线性动力学和混沌理论研究涡激激励

• 批准号: 11650247
• 负责人: MUREITHI W.njuki
• 金额: $ 2.11万
• 依托单位: Kobe University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650247/
• 关键词: Inline vortex shedding; Lock-in; Bifurcation; limit cycle oscillator; vortex merging; secondary instability; vortex row; 渦結合; アベレージング解析; ホップ分岐; ロックイン; 非線形ダイナミクス; ファレイ組成; サドルノード分岐

This project involved an in depth investigation of the dynamics of vortex-structure interaction. The lift oscillator model concept was reviewed and expanded. In the new approach proposed in this work the parameter space in the neighborhood of the Hartlen＆Currie (HC) model was searched. Continuation analysis, equivalent to numerical unfolding, showed that the neighborhood of the HC models, contains models revealing unexpected physically meaningful dynamics. A connection between vortex excitation of rigid structures and their flexible counterparts was found. Bifurcation and continuation analysis was found to be an effective tool in the search for feasible dynamical models. Peturbation analysis of the lift oscillator in the second part of this work showed that lock-in behavior was prevalent. The 2/1 lock-in was dominant. Furthermore, an analysis of a truncated form of the Navier-Stokes equations confirmed that a planar 2D inviscid flow can exhibit 3D secondary instabilities dominated by the 2/1 component, in qualitative agreement with the perturbation analysis. Finally, the foregoing findings were tested experimentally. Flow visualization coupled with hot-film anemometry showed convincing evidence that the dominant instabilities are actually physically manifested by the fluid-structure system.

该项目对涡旋-结构相互作用的动力学进行了深入的研究。回顾和扩展了升力振子模型的概念。在本文提出的新方法中，搜索了Hartlen&Currie(HC)模型邻域内的参数空间。延拓分析，相当于数值展开，表明HC模型的邻域包含揭示意外的物理意义的动力学的模型。发现了刚性结构的涡激与柔性结构的涡激之间的联系。分支和连续分析被发现是寻找可行的动力学模型的有效工具。本文第二部分对升降机振荡器的脉动分析表明，锁定行为是普遍存在的。2/1锁定占主导地位。此外，对截断形式的Navier-Stokes方程的分析证实，平面二维无粘流动可以表现出由2/1分量主导的三维二次不稳定，这与摄动分析定性地一致。最后，对上述研究结果进行了实验验证。流动显示与热膜风速测量相结合显示了令人信服的证据，表明主要的不稳定性实际上是由流体-结构系统物理表现出来的。

项目成果

Mureithi N.: "Vortex Wake Secondary Instabilities and Mode Lock-in"Journal of Sound and Vibration. (準備中). (2001)

Mureithi N.：“涡流二次不稳定性和模式锁定”声音与振动杂志（2001 年）。

Mureithi N.: "Flow Induced Vibration, eds.S.Ziada & T.Staubi,"Bifurcations and perturbation analysis of some vortex shedding models""A.A.Balkema/Rotterdam/Holland. 61-68 (2000)

Mureithi N.：“流动引起的振动，eds.S.Ziada

Mureithi N.: "A Nonlinear Dynamics Analysis of Vortex-Structure Interaction Models"Proc.Symp.FIV ASME/PVP Conf.2001. (印刷中). (2001)

Mureithi N.：“涡-结构相互作用模型的非线性动力学分析”Proc.Symp.FIV ASME/PVP Conf.2001（印刷中）。

Mureithi N.: "Bifurcation Analysis of Some Basic Vortex Shedding Models"Proc.Asia Pacific Vibration Conference. Vol.1. 559-564 (1999)

Mureithi N.：“一些基本涡旋脱落模型的分岔分析”Proc.亚太振动会议。

Mureithi, N.W., Goda, S., Kanki, H., Nakamura, T.: "A nonlinear dynamics analysis of vortex-structure interaction models"In Flow-Induced Vibration, ASME-PVP. (in print). (2001)

Mureithi, N.W.、Goda, S.、Kanki, H.、Nakamura, T.：“涡结构相互作用模型的非线性动力学分析”，载于流致振动，ASME-PVP。