Numerical simulation and model test study on hydraulic characteristics of baffle-drop shaft

In this paper, the numerical simulation and model test are conducted to study hydraulic characteristics of baffle-drop shaft based on waste landfill project. First, a three-dimensional model is built using ANSYS Fluent to simulate pressure distribution, flow velocity and gas-liquid phase distribution in the baffle-drop shaft. Second, the flow pattern of the baffle-drop shaft under different working conditions is further analyzed based on a model test. Third, a structural optimization design for baffle-drop shaft is proposed. The simulation and test results showed that the pressure distribution remains relatively uniform, with localized pressure maxima observed at each baffle terminus and the shaft base. The flow velocity undergoes progressive attenuation through successive baffle interactions. The water tongue descends maximally to the confluence of the baffle and shaft wall, with no detrimental wall-attached flow pattern regimes observed. To reduce water flow oscillation at baffle and overflow phenomena at vent, this study improved the structure design of baffle-drop shaft by installing of rectifier plate above each baffle and adjusting the position of vent from the edges to the central region of the baffle. It is found that the energy dissipation of improved baffle-drop shaft is well, and the intense lateral oscillation of the water flow can be effectively suppressed. The vent can maintain unimpeded ventilation functionality.