新型低水头抽水蓄能机组中涡旋演化机制与压力脉动耦合的前瞻性评估

Abstract Low-head pumped hydro energy storage (PHES) units, as a new type of regulation equipment under China’s policy of local renewable energy consumption, exhibit significant stability challenges influenced by turbulent vortex evolution within the runner. However, the underlying mechanism linking key vortex structures to unit instability remains unclear. This study systematically investigates the evolution of three-dimensional corner vortices in the runner and their cross-scale effects on hydraulic efficiency and pressure fluctuations through combined experimental and numerical approaches. The main findings are as follows: (1) A quantitative correlation between vortex intensity and efficiency loss is established, revealing that a 10 s −1 increase in vortex strength reduces hydraulic efficiency by 1.33 percentage points. (2) The rigid vorticity transport equation decouples shear and rotation effects, revealing the inherent coupling limitation of conventional vorticity transport equations in separating shear strain from rigid rotation. Results confirm that the rigid vorticity curl term (RCT) dominates vortex generation via tube stretching (contributing 85.91 %–87.41 %), thereby driving multi-scale flow dynamics. (3) This study reveals an anti-phase coupling mechanism among rigid vorticity ( ω R ), shear vorticity ( ω S ), and pressure fluctuations, showing amplitude decays of 49.5 %, 44.2 %, and 40.7 % along the vortex evolution path, with about 75 % energy dissipation. The RCT term drives a shear flow → ω S → ω R → pressure energy cascade, providing a new theoretical paradigm for vortex control and stability optimization in low-head PHES units.