内孤立波作用下Spar平台的运动响应
The motion responses of a Spar platform under internal solitary wave
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摘要: 建立了内孤立波作用下Spar平台运动响应的时域数值模型,并利用这一模型计算了内孤立波作用下Spar平台的运动响应。其中根据K-dv方程解出内孤立波的波面及水质点速度表达式,应用Morison公式求出内孤立波对Spar平台的水平作用力;由伯努力方程求解压强,通过在平台底面积分求出内孤立波对Spar平台的垂向作用力;在悬链线理论的基础上,分析锚链对平台的作用力,采用四阶Runge-Kutta方法求解运动方程。数值结果表明,当内孤立波不断接近海洋平台时,Spar平台受到的作用力随之增大,海洋平台会产生远大于表面波作用下的水平位移,从而证实了内孤立波是影响海洋平台稳定的重要因素,在海洋平台的设计和评估中内孤立波的作用是不可忽略的。Abstract: In this paper, a time-domain numerical model is established to consider the motion responses of a Spar platform induced by internal solitary wave which satisfies the K-dv equation. The horizontal force on the Spar is computed by Morison equation and the vertical force is computed by integration of the fluid pressure on the Spar bottom based on Bernoulli equation. The catenary theory is used to analyze the mooring force. The motion equation is solved by using fourth-order Runge-Kutta method. The numerical results show that when the internal solitary approaches to the Spar platform, the platform produces a much greater displacement comparing with the displacement induced by the surface waves. It is approved that internal solitary wave is one of the important effecting factors for the stability of offshore platform. Therefore the influence of internal solitary wave on the deep-sea platforms can not be neglected in design and estimation.
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Key words:
- internal solitary wave /
- Spar platform /
- Morison equation /
- catenary theory /
- motion response
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