Pressure pulsation characteristics of the generating pump-turbine in hydraulic short-circuit mode of a two-unit one-tunnel pumped storage system

Key Points

• This research investigates how hydraulic short-circuit mode affects pressure pulsation in a pump-turbine system.
• Utilized a validated three-dimensional computational fluid dynamics model
• Conducted coupled simulations for a prototype pumped storage system
• Compared results with conventional dual-unit generation mode
• Hydraulic short-circuit mode significantly amplifies pressure pulsations
• The effect is pronounced for low-frequency pulsations near the bifurcation
• Strong flow impacts and flow separation occur at the bifurcation, leading to increased vortex structures
• Increased vortex structures lead to greater local energy dissipation and enhanced pressure pulsation