Hydraulic and heat transfer characteristics in corridor-shaped air-cushion surge chambers in hydropower systems.

This article focuses on the hydraulic and heat transfer characteristics of corridor-shaped air-cushion surge chambers used in hydropower systems, employing three-dimensional numerical simulations based on the shear stress transfer (SST) k–ω turbulence model combined with the volume of fluid (VOF) method. It analyzes the effects of parameters such as throttle orifice size, chamber aspect ratio, initial water depth, and unit shutdown time on pressure fluctuations, jet formation, vortex behavior, and heat transfer during load variations. Key findings include that larger orifice sizes reduce jet height and surge amplitude while increasing heat transfer rates, and that vortex-induced air entrainment into the pipeline is influenced by orifice size, chamber geometry, and load conditions. The study also develops a novel heat transfer calculation method for corridor-shaped chambers and highlights the importance of understanding fluid–air interactions to improve the safety and efficiency of hydropower surge chambers.