Hydraulic characteristics of a large rotation-angle baffle-drop shaft through synergetic discharge from dry and wet sides

Abstract

To enhance the operational capacity and space utilization of baffle-drop shafts, this study improved the traditional baffle-drop shaft by expanding the wet-side space, incorporating large rotation-angle baffles, and installing overflow holes in the dividing wall. A three-dimensional turbulent model was developed using ANSYS Fluent to simulate the hydraulic characteristics of both traditional and new baffle-drop shafts across various flow rates. The simulation results demonstrated that the new shaft design allowed for discharge from both the wet and dry sides, significantly improving operational capacity, with the dry side capable of handling 40% of the inlet flow. Compared to the traditional shaft, the new design reduced shaft wall pressures and decreased the mean and standard deviation of pressure on typical baffles by 21% and 63%, respectively, therefore enhancing structural safety. Additionally, the new shaft achieved a 2%–12% higher energy dissipation rate than the traditional shaft across different flow rates. This study offers valuable insights for the design and optimization of drop shafts in deep tunnel drainage systems.