Severe pressure pulsations caused by complex flow fields in pumped-storage power stations significantly threaten operational safety. This analysis demonstrates why a fully three-dimensional simulation coupling the pipeline and the pump-turbine unit is essential.

1. The Critical Flaw of 1D Modeling

Current simulation practices often use 1D models. Our comprehensive 3D analysis reveals a fundamental flaw in this approach:

The study reveals a strong bidirectional coupling between the flow in the long outlet pipe and the internal flow within the pump-turbine unit.

2. Results and the Propagation of Pulsations

The detailed analysis of pressure pulsations reveals how instability spreads throughout the system:

• Near Impeller: Pressure pulsations are most intense here, dominated by high-frequency components.
• Downstream Attenuation: Amplitude decreases downstream.