海流作用下坠物沉降及撞击海底管道数值模拟研究
Numerical simulation of falling objects settling and impacting submarine pipelines under the action of ocean currents
杨明 1刘巨保 1丁宇奇 1黄茜 1靳翔1
作者信息
- 1. 东北石油大学机械科学与工程学院,黑龙江大庆 163318
- 折叠
摘要
采用基于浸入边界-有限元法的流固耦合数值模拟方法,对海流作用下坠物撞击海底管道完整过程进行了数值模拟研究.数值结果表明:在自由沉降时,坠物的流向速度与海流速度基本一致,不同海流速度下相同质量的坠物垂向速度基本一致,但在较低的坠物质量和海流速度下会出现冲跃现象,球形坠物的垂向阻力系数比立方形坠物小,并且阻力系数随坠物质量的变化而变化,坠物沉降角度随海流速度的增加而增大;在坠物接近海底管道时,流向速度逐渐减小,垂向速度均为先增大后减小,立方形坠物减小程度要比球形坠物大,质量大的坠物垂向速度减小的程度也要比质量小的大;在坠物撞击管道时,球形坠物撞击速度比立方形大,撞击速度比自由沉降速度大,撞击角度比自由沉降角度小,最大应力和凹痕均比无海流作用时小,球形坠物应力减小幅度为4.44％～16.71％,立方形坠物应力减小幅度为9.29％～12.14％,球形坠物凹痕减小幅度为4.17％～30.58％,立方形坠物凹痕减小幅度为10.41％～14.44％.
Abstract
The dynamic boundary problem of falling objects in ocean currents is simulated by the sharp interface immersed boundary method.The settling motion of a falling object and its collision with a pipeline are solved by the finite element method based on the penalty function.The coupling solution of the falling object and ocean current is obtained by the partitioned coupling approach.The complete process of the falling object impacting the submarine pipeline under the action of ocean current is numerically simulated.The numerical results show that the flow velocity of the falling object is almost the same as that of the ocean current in free settling.The vertical velocity of falling objects with the same mass is almost the same under different current velocities.However,thrust occurs at lower mass and current velocity.The vertical drag coefficient of spherical objects is smaller than that of cubic objects,and the drag coefficient changes with the mass of objects.When the falling object approaches the submarine pipeline,the flow velocity decreases gradually,and the vertical velocity increases first and then decreases.The vertical velocity of heavy objects decreases more than that of low-mass objects.When the falling object hits the pipe,the impact velocity of the spherical falling object is larger than that of the cube.The impact velocity is larger than the free sedimentation velocity and the impact angle is smaller than the free sedimentation angle.The maximum stress and indentation are smaller than that without current action.The stress reduction range of spherical falling objects is 4.44％-16.71％,and the stress reduction range of cubic falling objects is 9.29％-12.14％.The dent reduction range of spherical falling objects is 4.17％-30.58％,and the dent reduction range of cubic falling objects is 10.41％-14.44％.Compared with past research,the method in this paper is more realistic,and the research results can provide a certain reference for the design of submarine pipeline engineering.
关键词
安全工程/海底管道/撞击/流固耦合/浸入边界-有限元法/数值模拟Key words
safety engineering/submarine pipeline/impact/fluid-structure interaction/immersed boundary-finite element method/numerical simulation引用本文复制引用
基金项目
国家自然科学基金项目(11972114)
黑龙江省自然科学基金项目(LH2022A003)
出版年
2024
NETL
NSTL
维普
万方数据