Development of rational design methodology of deep sea riser

深海立管合理设计方法的发展

• 批准号: 07555319
• 负责人: OHKUSU Makoto
• 金额: $ 5.7万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555319/
• 关键词: deep sea; riser

We completed a computer code to numerically simulate the behaviors of deep sea riser.Both finite difference and finite element modeling have been studied for the code ; the latter was employed. Riser body is divided into numerous segments. Local bending and torsion are represented by the relative displacement of neighboring segments which are assumed rigid. Nevertheless each segment is assumed to extend and compress responding to tension and compression.We derive the equation of motion of a system of the segments from Lagrangean function of a system written in the Euler angle of each segment. Hydrodynamic forces on the segments, added mass and drag force, are computed assuming that the relative flow occurs in the plane normal to the axis of the segment cylinder and has no component into the axis.Our computer code was validated by comparing the simulated motion, tension and bending moment, with the measured ones obtained in the experiments. The experiment are with the hang-off condition of a riser and the forced motion given by the supporting platform floating in waves.We designed a deep sea riser by using the computer code we developed.

本文编制了一套深海立管的数值模拟程序，该程序采用了有限差分法和有限元法两种建模方法，并采用了有限元法。隔水管主体分为多个段。局部弯曲和扭转由假定为刚性的相邻段的相对位移来表示。然而，我们假设每一段都响应于拉伸和压缩而伸展和压缩，我们从写在每一段的欧拉角上的系统的拉格朗日函数导出了段系统的运动方程。假设相对流发生在垂直于圆柱轴线的平面内，并且没有进入轴线的分量，计算了作用在圆柱段上的附加质量和阻力，并通过将模拟的运动、张力和弯矩与实验测量值进行比较，验证了计算程序的有效性。实验是以立管的悬挂条件和支撑平台在波浪中的受迫运动为条件，利用开发的计算机程序设计了一个深海立管。