Investigating pressure changes at the bottom of the stilling basin after the stepped spillway using a numerical model

Stepped spillways are hydraulic components of dams used to dissipate energy downstream of the dams. Numerous studies have been conducted to understand the hydraulics of flow on stepped spillways, primarily in laboratory settings. The flow passing over stepped spillways can be categorized into two types of flow regimes: Nappe Flow and non-Nappe Flow. In this research, the FLOW-3D software was utilized to model the Cardan configuration of the downstream basin of the stepped overflow based on laboratory data. In this investigation, we compared the distribution profile of maximum, minimum, and average pressures in three areas: the center, right, and left, with the laboratory data in the numerical model using graphical methods and statistical indicators. The results revealed that 08% of the pressures obtained from the model closely matched the laboratory data with an error rate of only 5.1%.