Author(s): Prajakta P. Gadge; Kunal Kapur

Linked Author(s): Prajakta Gadge

Keywords: Overflow spillway; spillway gates; physical model; numerical model; discharging capacity

Abstract: The spillway is among the most important structures of a dam project. The operation of spillway gates during the flood and fulfilling the downstream requirement is one of the main problems in reservoir management. Generally, the equal opening of all the gates during spillway operation is mostly preferred for maintaining an equal distribution of discharge in the energy dissipator and at the downstream side. A systematic study is required to determine the ability of the spillway to pass the discharge at various reservoir water levels through a specific opening of gates and assess the performance for the safety of the structure. The design of each project is unique and site-specific. A physical model is an indispensable tool to optimise the hydraulically efficient and economical design of spillways. However, the evaluation of spillway performance especially for the partial operation of gates is a time-consuming task on the physical model. Nowadays, the computational fluid dynamics technique is becoming popular in modelling spillway flows. This paper discusses the studies carried out for overflow spillway for gated and ungated operations. The Computational fluid dynamics software FLOW-3D was used for numerical simulation. The numerical model was validated by comparing the results with the physical model for ungated operations. The results in terms of design discharge passed over the spillway and corresponding pressures over the spillway surface computed using a numerical model were found closer to the results obtained from the physical model. Numerical model studies were extended further for the gated operation. Large data was generated which was used to create discharging capacity plots and evaluate the performance of the spillway for operating the spillway with different openings of gates at various reservoir water levels.

DOI: https://doi.org/10.26077/442f-a552

Year: 2022