内流对两端铰支水下输油管线管壁应力影响的数值分析

Numerical Analysis on Influence of Internal Flow on the Pipe Wall Stress of Submarine Pipeline with Hinged Support

针对两端铰支水下输油管道，分别采用三维弹性动力学方程和N-S方程模拟管道与内部流体；借助ADINA有限元计算软件，管线采用壳模型四边形9节点单元离散，内部流体采用四面体4节点单元离散，通过在流固边界上反复迭代，实现管线及内部流体系统的三维流固耦合计算。管线外部环境条件考虑了管线外壁水压力的分布。依据数值计算得到的管线耦合系统的固有频率与HOUSNER方程的理论解的比较，探讨了不同内流流速对不同跨长管线管壁应力的影响，以及考虑管线外壁水压力作用的计算结果与通常假定管线在空气中的计算结果的差别。

The 3-D fluid-structure interaction of submarine oil pipeline with hinged support and internal flow is numerically simulated by applying the iterative computation to the fluid-structure interfaces. The pipeline and internal flow are governed by the 3-D elasto-dynamic equation and N-S equation of laminar model respectively. The 9 node quadrilateral elements of shell model are used to the pipe wall and the 4 node tetrahedral elements are used to the internal flow in ADINA programmer. The effect of hydrostatic pressure is considered by distributing the pressure on the pipeline wall. The natural frequency of the system is calculated and compared with the theoretical solution of Housner＇ equation. The method can concern with the fluid features such as fluid velocity and fluid pressure distribution. The impact of internal flow on stress of submarine pipeline with hinged support is discussed by changing span-length and internal flow velocity.