Theoretical analysis of the attenuation characteristics of high-frequency pressure vibration in pumped storage power station

High-frequency vibration is a common hydraulic phenomenon in pumped storage power station. In this study, a theoretical model for analyzing the high-frequency vibration in fluid-pipe-surrounding support coupling system is established. The discontinuity characteristics between the pipe wall and surrounding medium are modeled by the linear spring model, where axial and radial spring constants represent the bounding degree of the pipe and surrounding support. The relation between the wave speed and attenuation characteristics of the high-frequency vibration could be derived from the established theoretical model. And a strategy for estimating the attenuation rate of the high-frequency vibration is proposed. According to the theoretical analysis results, the connection and transition of the vibration energy through the pipe and surrounding support mainly rely on radial bounding. With decreasing in the compressibility of the pipe wall and the surrounding medium, the attenuation rate of high-frequency decreases. One of the reasons why the high-frequency pressure vibration could propagate over long distances in the pumped storage power station may be attributed to the little compressibility of the solid structures in the headrace tunnel.