稳定流作用下海底悬跨管线涡激振动研究

讨论了目前用于海底悬跨管线涡激振动预报的主要数值模型,针对海底管线悬跨段涡激振动问题编制了有限元分析程序,程序采用梁单元模拟管跨结构,动力响应计算方法采用VIVANA模型,模型控制方程采用Newton-Raphson迭代算法求解。采用Larsen,Koushan等人(2002)和Larsen,Baarholm等人(2004)给出的两组不同的用于确定升力曲线的参数曲线进行计算,将计算结果与Tsahalis(1984,1987)的模型实验结果进行了比较。结果表明本文的涡激振动模型能够预报间隙比e/D=∞时海底悬跨管线的涡激振动响应;采用Larsen,Koushan等人(2002)参数曲线得到的计算结果与间隙比e/D=∞时的实验结果符合较好,Larsen,Koushan等人(2002)参数曲线较Larsen,Baarholm等人(2004)参数曲线更适合于海底悬跨管线的涡激振动预报。

Vortex-Induced Vibrations of free span pipelines exposed to steady currents

The various models for vortex-induced vibrations (VIV) of submarine free span pipelines are discussed.Combining the VIVANA model with a flexible beam model,a computer analysis program is developed for cross-flow VIV.The Newton-Raphson method is used to solve the dynamic equilibrium equation.Calculations are carried out using two different groups of parameter curves from Larsen et al (2002,2004),respectively.The calculated results are compared with Tsahalis’ (1984,1987) experimental results from laboratory model tests of a flexible cylinder near a plane boundary exposed to steady currents.It is shown that the calculated results using Curve1 where the maximum response amplitude for zero lift (i.e.CL=0) is from free vibration tests are good agreement with test results for a gap ratio of e/D=∞,and Curve1 is more suitable for the VIV analysis of submarine free span pipelines.