Journal Article

Dynamic Response of Fluid-Solid Coupled Penstock-Mountain System Under Geostress Effects

Yan, Yuhao, Zhang, Zhengping, Zhao, Xiaodong, Wu, Huanyu, Lin, Xiaobin, Wang, Zhengwei

2025

Overview

Pumped storage power plants (PPSPs) have attracted significant attention for their contribution to grid stability. An increasing number of power plants choose to be buried deep underground and designed with long penstocks. However, in high-head power plants, water hammer waves are prone to accumulation and diffusion, triggering vibrations in the pipeline and mountain. Therefore, the aim of the present study is to clarify the fluctuation characteristics in the fluid and further investigate the dynamic response of the penstock-mountain system under oscillation. This study adopts a 3D Fluid-Solid Coupled method to calculate and analyze the fluctuations and stresses across the studied area under the condition of load rejection without closing the spherical valve of the units. The results show that during the load rejection process, there is a violent fluctuation period, with the maximum peak-to-peak amplitude reaching 0.937 MPa. Based on this period, further analysis reveals that there are stress-concentrated areas near the T-joint. The maximum principal stress (MPS) at T-joint can reach more than 4.55 MPa, with a large oscillation intensity. In violent period, as depth increases, the contribution of Norm Z stress in mountainous areas grows, accompanied by changes in frequency characteristics and amplitude. The simulation method proposed in this paper can be extended to other penstock-mountain systems, providing references for the safe operation of PPSPs.

• Publisher: IOP Publishing
• Subject: Amplitudes / Dynamic response / Mountainous areas / Mountains / Penstocks / Power plants / Pumped storage / Rejection / Tee joints / Water hammer