During the operation of a curved stepped spillway, a significant bias flow phenomenon may occur due to centrifugal force, potentially leading to an exposed bed of the inner bank and excessive water depth on the outer bank in severe cases. In order to address the uneven lateral water flow distribution, the transverse slope, where the bottom bed elevation of steps along the outer bank is higher than that along the inner bank, was designed to optimize the hydraulic characteristics of the curved step spillway. Through physical model experiments and three-dimensional numerical simulations, the hydraulic characteristics, including the water surface profiles, flow velocity, pressure on the spillway bed and energy dissipation, were obtained under different discharges and transverse slope angles. The results show that the transverse slope can reduce the bias flow and enhance the uniformity of flow velocity and pressure distribution by balancing centrifugal force. The rational matching of transverse slope angle and discharge is critical for optimizing the hydraulic characteristics of the curved stepped spillway. An appropriate transverse slope angle can effectively alleviate the excessive bias flow phenomenon and ensure uniform distribution of flow velocity, thereby improving the operational stability of the spillway.
Chen et al. (Thu,) studied this question.