Flow over Ogee Spillway: Physical and Numerical Model Case Study

A study was completed to compare flow parameters over a standard ogee-crested spillway using a physical model, numerical model, and existing literature. The physical model was constructed of Plexiglas and placed in a test flume. Pressure taps were installed along the entire length of the spillway. Discharge and pressure data were recorded for 10 different flow conditions. A commercially available computational fluid dynamics (CFD) program, which solves the Reynolds-averaged Navier-Stokes equations, was used to model the physical model setup. Data interpolated from U.S. Bureau of Reclamation and U.S. Army Corps of Engineers design nomographs provided discharge and pressure data from the literature. Nondimensional discharge curves are used to compare the results from the different methods. Pressures are compared at low, mid, and high flow conditions. It is shown that there is reasonably good agreement between the physical and numerical models for both pressures and discharges. The availability and power of existing numerical methods provides engineers with another tool in the design and analysis of ogee spillways.