Numerical Investigation of Flow Characteristics of Broad-Crested Weirs with Different Geometry

Broad-crested weirs are important hydraulic structures used for water level control and flow regulation. In the literature, novel designs with upstream and downstream slope angles have been made to increase the discharge capacity of these structures, which are generally designed with vertical upstream and downstream faces. This study numerically investigates the effect on the flow characteristics of broad-crested weirs whose crest is inclined and whose upstream and downstream faces are stepped. The open-source software OpenFOAM and the k-ε turbulence model are used for the numerical analysis. The numerical results are validated with the literature study of a classical broad-crested weir (Imanian et al., 2021). According to the results, it is seen that the discharge capacity of the newly designed models is about 4% higher than the classical broad-crested weir, and the discharge capacity of the models with negative crest slope is higher. In addition, the discharge capacity is higher, and the flow separation zone is lower in the models designed with stepped upstream and downstream surfaces.