流体激励下弯管流固耦合振动特性分析

Finite Element Analysis of Fluid-Structure Interaction Vibration for Curved Pipe of the Surface Manifold in Oil Testing

流体流经弯管时,由于管道结构改变,流体冲击弯曲管壁形成激励,使弯管发生振动。振动的弯管反过来又会影响流体流态,形成流固耦合振动。利用ANSYS Workbench软件,建立弯管和流体有限元模型,进行流体激励下弯管流固耦合振动特性分析,考察流体波动频率对弯管流固耦合振动幅值的影响。分析结果表明:考虑流固耦合作用,弯管的固有频率降低;与考虑双向流固耦合作用相比,单向流固耦合作用时弯管振动变形与应力较小;当流体流经弯管时,最大等效应力出现在管道入口端和出口端,最大变形出现在弯管弯曲段;流动流体激励下弯管流固耦合振动的主要形式为横向振动。

The surface pipeline or manifold of well testing and acid fracturing contains the curved pipe,and fluid structure interaction vibration is formed when fluid flowing through pipeline,which will affect the mechanical properties and reduce the reliability of the pipeline,therefore,to study the coupling vibration between fluid and pipe has great of significance to the safety of the pipeline system. Based on the fluid-structure interaction theory and finite element theory,the finite element model of fluid conveying curved pipe is established,and using ANSYS Workbench,stress and deformation under the fluid force of pipe is calculated,and the influence of the pipe by different fluid pulsation frequency amplitude has been analyzed. The results show that when the fluid flows through the pipe,the maximum equivalent stress appears at the top inlet and at the left outlet of pipe,the maximum deformation appears in the pipe bending section; the results when considering the effect of single FSI are smaller than the results when the two way FSI is considered; The main vibration mode of the pipe is lateral vibration,and the amplitude of the pipe increases with the increase of fluid pulsation frequency,when the velocity is constant,the fluid pulsation frequency closer to the natural frequency of the pipe,the amplitude of the pipeline is larger.