Fluid-structure interaction analysis of the return pipeline in the high-pressure and large-flow-rate hydraulic power system

This paper aims to investigate the dynamic characteristic of the return pipeline in the high-pressure and large-flow-rate hydraulic power system. First, the geometry model of the pipeline is established, and a one-way coupling fluid structure method is introduced. The modal analyses with empty and filled pipelines are performed and compared. Then, the pipeline resonance phenomenon is investigated, and the response frequency is achieved by the fast Fourier transformation (FFT) analysis, the results are inconsistent with the experiments. Besides, the dynamic response of the pipeline is simulated. Dynamic mesh and user define function (UDF) are adopted, and the pipeline vibration and water hammer phenomenon are observed. Finally, the dynamic characteristics of the pipeline under different fluid velocities and wall thickness are investigated. The results show that the pipeline valve-induced vibration cannot be lightened by reducing the fluid inlet velocity but can be significantly mitigated by increasing the wall thickness.