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%。
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.
作者
杨明
刘巨保
丁宇奇
黄茜
靳翔
YANG Ming;LIU Jubao;DING Yuqi;HUANG Qian;JIN Xiang(College of Mechanical Science and Engineering,Northeast Petroleum University,Daqing 163318,Heilongjiang,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2024年第4期1371-1380,共10页
Journal of Safety and Environment
基金
国家自然科学基金项目(11972114)
黑龙江省自然科学基金项目(LH2022A003)。
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
safety engineering
submarine pipeline
impact
fluid-structure interaction
immersed boundary-finite element method
numerical simulation
