Numerical Evaluation of Self-Aeration in the Gelas Tunnel Intake: A Comparative Study Using VOF and Mixture Methods

This present work explores the self-aeration within the Gelas tunnel intake to accurately predict air demand and to analyze flow dynamics through advanced numerical methods. Volume of fluid (VOF) and mixture methods were used to model air-water interactions to ensure the safe and effective operation of hydraulic structures because traditional empirical models frequently fail to capture the complexity of these interactions, especially in large-scale systems like the Gelas tunnel. Our results demonstrate that, with a relative error of only 22% when compared to empirical standards, the VOF technique performs much better in air demand predictions than the mixed method. The combination method overestimated the demand in this case by more than 153%. Furthermore, the VOF method accurately simulated not only flow depth but also air concentration and hydraulic jump dynamics which makes it a more reliable tool for modeling such complex phenomena. These results underscore the importance of integrating advanced numerical simulations into the design of essential hydraulic systems to enhance their safety and operational efficiency and offer valuable insights for the future design and optimization of water conveyance infrastructure.