Analytical solution of mean top tension of long flexible riser in modeling vortex-induced vibrations

作者：Gu, Jijun^*; Wang, Yi; Zhang, Yu; Duan, Menglan; Levi, Carlos

来源：Applied Ocean Research, 2013, 41: 1-8.

DOI：10.1016/j.apor.2013.01.004

• Wake oscillator model
• Riser
• VIV prediction
• Top tension
• Multi-mode

The vortex-induced vibration (VIV) of flexible long riser with combined in-line and cross-flow motion has been studied using a wake oscillator in this paper. The analytical solution of mean top tension of long flexible riser is evaluated and compared with experimental results, and good agreement is observed to verify its validity. Then the nonlinear coupled dynamics of the in-line and cross-flow VIV of a long tension-dominated riser were analyzed through wake oscillator model with the consideration of variation of the mean top tension. The in-line and cross-flow resonant frequencies, lift and drag coefficients, dominant mode numbers, amplitudes and instantaneous deflections are reported and compared with experimental results, and excellent agreements are observed. The comparison of mode numbers between the calculation with and without consideration of variation of mean top tension shows that the proposed analytical solution of the mean top tension can produce a better prediction of multi-mode VIV.

• 出版日期2013-6
• 单位中国石油大学（北京）