Hydraulic characteristics of flow over stepped and chute spillways (case study: Zirdan Dam)

Abstract Stepped spillways are suitable and economical options for high-storage dams that require significant energy dissipation, structural adaptation to roller-compacted concrete dams, spontaneous flow aeration. In this study, a numerical analysis of the hydraulic characteristics skimming regime stepped spillway Zirdan Dam is carried out. A comparison between smooth provided. By preparing models using k-ε RNG turbulence model multiphase mixture method, was completed. To verify performance model, field data were collected used validation. The results show presence steps along cause reduction in length boundary layer faster aeration occurs. spillway, cavitation index higher than critical limit entire spillway. Thus, risk destruction negligible. On other hand, with possibility may occur. This negative effect (negative pressures) occurs 56 m from crest on downstream side.