海洋环境荷载下输液立管的静、动力特性研究

Study on Static and Dynamical Analysis of a Marine Riser Conveying Flowing Fluid Subjected to Environmental Loads

考虑管内流动流体和管外海洋环境荷载共同作用 ,建立海洋立管侧向运动微分方程。用Hermite插值函数离散 ,在微机上编写海洋立管静、动力分析程序 ,通过计算分析研究管内流体对立管侧向变形和应力的作用 ;另外 ,探讨管内流体的流动速度和立管顶端的预张力对立管动力特性的影响。结果表明 ,立管变形和应力均随管内流体流动速度增加而增大 ,同时内流速度的增大会降低立管的固有频率 ,但适当增大立管顶端预张力会抵消内流流速增加引起的固有频率下降。

Considering the internal flowing fluid and the external environmental loads, the lateral vibration differential equation of a marine riser is derived. Discretization is made with Hermite interpolation function and codes of computing the deflection and the dynamics of a marine riser has been written. The effect of internal flow velocity on the lateral deflection and stress is studied. A preliminary relationship between the natural frequency and the internal flow speed and the top tension of the riser is obtained. Results indicate that the deflection and stress increase with the increase of the internal flow velocity. Increasing internal flow velocity can make the natural frequency of the riser lower while the increase of the top tension can counteract this effect.