海底管线柔性导流板的变形方程研究

海底输油管线是海洋油气田开发的生命线工程,在复杂的海洋环境中易发生破坏.为使管线实现自埋防护,提出用柔性材料代替刚性导流板安装在管线顶部,不仅可以增加阻水面积,加大冲刷深度和范围,而且可以减缓刚性导流板对管线上部水流的扰动强度和尾流涡旋的扰动强度,减小管线的振动.利用力学关系由变形方程推导出海底管线与海底间距离为零以及不为零情况下柔性导流板变形的二次曲面方程和自由端最大挠度.在单向流条件下将不同材料不同长度的柔性导流板安装在管线中轴上方开展试验研究,测量柔性导流板在水流作用下的变形曲面.对比分析利用公式计算柔性导流板的自由端最大挠度和曲面变形数据与试验结果,发现两者吻合较好.

Study on the Deformation Equation of Flexible Spoiler Attached on Top of the Submarine Pipeline

Submarine pipeline is one of most important parts of the ocean oil field exploitation system,which can be damaged by the very complex ocean environment. To make the pipeline self-burying, thispaper proposes to use flexible spoiler instead of rigid spoiler attached on the top of the pipeline, which cannot only increase the scour depth and range, but also abate both turbulence intensity the rigid spoiler actson the flow above the pipe and wake flow vortex so as to decrease vibration of the pipe. The quadraticcurved surface equation of deformed flexible spoiler and deflection of free end formula are deduced on thebasis of dynamical relation under the conditions of both interstice ratio is zero and is not zero. A series ofexperiments has been conducted under unidirectional current in which different material and length of flex-ible spoilers were installed on the top of the pipeline and the deformation of flexible spoilers is measured.By comparing the maximum deflection of free end and deformation of curved surface calculated by formu-las with the data measured from experiments, find the two values are very close to each other. Thereforethe formulas can be used to calculate the deformation of flexible spoiler attached on top of the pipeline ap-proximately.