Author(s): Fatna Oukaili; Yvan Bercovitz; Cedric Geoury; Fabrice Zaoui; Thomas Fonty; Francois Jouve

Linked Author(s): Fatna Oukaili, Yvan BERCOVITZ, Fabrice Zaoui, Thomas Fonty

Keywords: Overflow spillways; Volume Of Fluid; Multi-fidelity shape optimization; Surrogate model

Abstract: Spillways are hydraulic structures that ensure safety and prevent failure of dams. They are designed to regulate flow and evacuate water during floods. Spillways are qualified by their capacity to evacuate water, which is quantified by flow discharge coefficient measurements. Crest weir shape is one of the main parameters that influence spillway efficiency. Currently, their geometry has only been studied empirically due to the complexity of flow. Despite being well studied experimentally, they have not yet undergone a thorough optimization study to enhance their efficiency. The present study aims to increase weir hydraulic performances. To carry out this purpose, a shape optimization methodology based on the Volume Of Fluid (VOF) model of Code_Saturne was developed to maximize flow discharge coefficients while at the same time taking into account damage risk by cavitation of the weir concrete. Conducted first on a 2D model, for a given flow rate, head discharge was minimized while limiting negative pressure appearance along weir crest. The multi-objective shape optimization study was based on a surrogate model by Kriging. In order to alleviate the computational cost, an efficient approach deploying different grid resolutions is proposed. A comparison between the optimal shape hydraulic performances and the standard weir shape highlights a significant improvement in weir efficiency.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022427

Year: 2022