基于协同仿真方法的U型橡胶结构涡致振动研究

Research on the vortex induced vibration of a U-shaped rubber structure based on co-simulation method

  • 摘要: 利用软件STAR-CCM+和Abaqus对气动载荷作用下U型橡胶结构涡致振动现象进行流固耦合协同仿真分析,并设计风洞试验对数值计算方法进行验证。流体场采用三维非定常粘性不可压缩k-ω湍流模型,固体场采用动隐式线弹性模型,研究了不同空气流速对U型橡胶结构变形及振动的影响规律,分析了U型橡胶结构振动频率与旋涡脱离频率的相互关系。结果表明,U型橡胶结构受到气动载荷作用由静止产生弯曲变形,风速越大其结构产生的弯曲变形量越大,并且弯曲变形振动频率接近一阶固有频率。当结构受到的气动力、弹性力、惯性力趋于平衡,结构上空气旋涡脱离导致结构持续振动,风速较低时,旋涡脱离的能量不足以强迫U型橡胶结构的振动与涡脱频率相一致。随着风速的增大,U型橡胶结构的振动是由旋涡脱离导致的受迫振动。

     

    Abstract: The fluid-structure interaction (FSI) analysis of the vortex induced vibration (VIV) of a U-shaped rubber structure under aerodynamic load is carried out by a co-simulation using STAR-CCM+ and Abaqus. Numerical results are verified by the wind tunnel tests. The three-dimensional unsteady viscous incompressible k-ω turbulence model is used in the flow field simulation. And the dynamic implicit elastic linear model is used to study the influence of different air velocities on the deformation and vibration of the U-shaped rubber structure. The vibration frequency of the U-shaped rubber structure, and its relationship with the frequency of the vortex are analyzed. Results show that the U-shaped rubber structure is subjected to aerodynamic load that produces bending deformations proportional to the wind speed. The vibration frequency of the bending deformation is close to the first-order natural frequency. When the aerodynamic force, the elastic force, and the inertial force of the structure tend to balance, the air vortex over the structure makes the structure vibrate continuously. But the vibration of the U-shaped rubber structure is only forced by the vortex detachment, i.e., the vibration frequency coincides with the vortex frequency, above a wind speed threshold.

     

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