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.

我们完成了对深海立管行为进行数值模拟的计算机代码。该代码对有限差分和有限元建模进行了研究；后者被雇用了。立管主体分为许多段。局部弯曲和扭转由假定为刚性的相邻段的相对位移表示。然而，假设每个段都响应拉伸和压缩而延伸和压缩。我们从以每个段的欧拉角写出的系统的拉格朗日函数推导了段系统的运动方程。假设相对流动发生在垂直于分段圆柱体轴线的平面上并且没有进入轴线的分量，则计算分段上的流体动力、附加质量和阻力。我们的计算机代码通过比较模拟运动进行了验证，拉力和弯矩，采用实验中测得的值。实验是针对立管的悬挂条件和支撑平台在波浪中漂浮所给予的强迫运动。我们利用我们开发的计算机代码设计了深海立管。