Numerical analysis of vibration of suspended pipelines in internal and external flow fields

摘要

In this paper, firstly, the suspended oil pipelines were numerically simulated under the impact of water flow based on the fluid-structure interaction and vibration theory of acoustic body after taking full account of the influence of internal and external fluid on the natural vibration frequency of the pipeline. In the flow field part, the finite element volume method was used to solve the arbitrary Lagrange Euler N-S equation, and in the structural domain, the finite element method discrete equation was used to transfer the data of the interaction surface. Then, the vibration of suspended pipelines in dry and wet mode was calculated and compared on this basis, and finally, the factors affecting the natural frequency of submarine pipelines and the response frequency of vortex-induced vibration were analyzed. The results showed that the natural frequency was greatly affected by the radius and the length of suspension; the natural frequency in the dry mode was about twice of that in the wet mode; the natural frequency in the wet mode was closer to the frequency of pipeline falling off, so the influence of internal and external fluid on the natural frequency of pipeline must be considered to avoid the resonance effect.