A numerical study on the effect of gate configuration on the hydraulic parameters of dam spillways

• Novel insights on flow depth and velocity variations in single vs. double-gate spillways. • Double-gate configuration leads to more uniform water height across the channel width. • Single-gate setup shows higher flow depth fluctuations, especially in mid-channel. Understanding the importance of hydraulic parameters affecting erosion is crucial for designing hydraulic structures, particularly in open channel spillways. While previous research has studied the impact of hydraulic parameters on the erosion of spillways, limited attention has been given to the specific influence of flow parameters in different gate configurations. To address this issue, our study provides a valuable understanding of the effects of flow depth, average, and maximum velocity variations in both single and double-gate scenarios using numerical modeling. The study utilized the computational fluid dynamics (CFD) software to conduct numerical simulations of the Romaine IV reduced scale spillway. Results show that the gate configuration has a great impact on flow depth and velocity variations. The division of a flow in the double-gate scenario, significantly influences the flow distribution, representing a more uniform water height across the channel width. However, flow depth fluctuations are higher in the single-gate setup, especially in the middle-width section. Furthermore, velocity variations show an important difference in the middle of the channel at the upstream, where the central pier functioning as a gate separator causes a local reduction in velocity, dropping to zero; after this point, the velocity values converge again demonstrating nearly similar values for the two scenarios.