Enhancing Dam Infrastructure Safety through CFD-Based Spillway Assessment

Abstract

Spillways play a crucial role in dam safety by controlling the release of excess floodwater. However, high discharge rates through these structures may lead to adverse hydraulic effects, such as cavitation and slug flow. This study examines these risks in the side spillway of the Krueng Kluet Dam, South Aceh, using a Computational Fluid Dynamics (CFD) approach. The model evaluates the flow conditions under operational discharges through velocity and pressure field simulations. The results indicate cavitation risk levels of 1 and 2—corresponding to no cavitation and potential cavitation—across most of the spillway. However, localized cavitation damage was detected near the downstream end of the chute at approximately 553 m and 580 m. These areas exhibited cavitation index values of 0.24 and 0.20, respectively. No signs of slug flow were observed in any section of the flow path. As a preventive measure, installing aerators or redesigning the chute with a stilling basin is proposed to reduce downstream flow velocity. This research provides design recommendations to improve spillway systems' hydraulic performance and safety and demonstrates the utility of CFD modelling for early identification of failure-prone zones.