Abstract A novel three-dimensional model is proposed to study vortex-induced vibration (VIV) problems of top-tensioned risers. The model is based on the vector form intrinsic finite element (VFIFE) method and applicable to the fully-coupled cross-flow and in-line riser VIV scenarios. The axial time-varying dynamics and movement at the top end boundary of risers are also considered in the model. By using the VFIFE method, the structure is reduced to a set of particles whose motion satisfies Newton's second law and its response is described by the position change of particles in space. The fluctuating fluid force acting on the structure induced by vortex shedding is simulated using the classical van der Pol wake oscillator equation. In order to intuitively describe the time-varying top tension of the real structure, the real-time changes in top tension caused by the array of tensioners simulated by spring is also considered. The results of numerical simulation on top tension, dominant mode numbers, frequencies, and amplitudes are compared with the experiment to prove that the VFIFE method is feasible and effective in predicting the three-dimensional vortex-induced vibration response.

中文翻译：

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基于矢量形式固有有限元法的顶张立管全三维涡激振动预测模型

摘要 提出了一种新的三维模型来研究顶张立管的涡激振动（VIV）问题。该模型基于矢量形式固有有限元 (VFIFE) 方法，适用于全耦合错流和直列立管 VIV 场景。模型中还考虑了立管顶端边界处的轴向时变动力学和运动。通过使用VFIFE方法，该结构被简化为一组运动满足牛顿第二定律的粒子，其响应由粒子在空间中的位置变化来描述。使用经典 van der Pol 尾流振荡方程模拟由涡旋脱落引起的作用在结构上的波动流体力。为了直观地描述真实结构随时间变化的顶张力，还考虑了由弹簧模拟的张紧器阵列引起的顶部张力的实时变化。将顶部张力、主模态数、频率和振幅的数值模拟结果与实验进行比较，证明VFIFE方法在预测三维涡激振动响应方面是可行和有效的。