Sürdürülebilir Kalkınma Amaçları
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- MakaleAçık Erişim2025Hydrodynamic optimization of full-scale aeration tanks using field measurements and computational fluid dynamics modeling
Yılmaz Çelik, Damla; Yılmaz, Naz; Şibil, Rahim; Aras, Egemen; Vaheddoost, Babak
Improving energy efficiency and operational performance in wastewater treatment plants largely relies on precise hydrodynamic analysis. In this context, field-based studies are essential for understanding system behavior under real operational conditions. This study was conducted at a full-scale wastewater treatment plant, where flow dynamics in the aeration tank were evaluated through extensive field measurements and computational fluid dynamics modeling. Data were collected from 98 locations across 15 different depth levels using an Acoustic Doppler Current Profiler and a Hach FH950 velocity meter. The numerical model was initially validated with the help of experimental field data, enabling an accurate assessment of flow characteristics at varying depths. Results revealed that the low-velocity zones and non-uniform velocity distributions negatively affect system performance. It is also concluded that the inlet and outlet positions disturb the favorable circulation patterns and flow uniformity. Geometric optimization strategies were implemented to develop solutions, which led to a more uniform velocity distribution and improved hydraulic efficiency. By integrating detailed field measurements with numerical modeling, this study provides a comprehensive understanding of aeration tank hydrodynamics and offers practical design recommendations for improving overall system performance.
- MakaleAçık Erişim2024Evaluation of turbulence models for the prediction of flow properties in vegetated channels
Sibil (Şibil), Rahim
The performance of turbulence models was investigated to predict the flow and turbulence features of the vegetated channel using computational fluid dynamics (CFD). The Ansys Fluent, CFD software was implemented for the numerical studies. The flow was three-dimensional, incompressible, steady, and turbulent. Ten turbulence models, provided by Ansys Fluent, were implemented for the comparative study. The numerical model was validated against an experimental study conducted in the literature. The numerical studies show that the Renormalization group k-ϵ model is the most successful model for predicting the flow characteristics of the vegetated channel with a Root Mean Square Error (RMSE) value of 0.2752. At the same time, the Reynolds Stress Model gives the least successful predictive performance, indicated by an RMSE value of 0.4302. Moreover, the Spalart-Allmaras (S-A) model offers the shortest computation time with a value of 6652.393 s, whereas the Shear Stress Transport k-ω model proves to be the most time-consuming with a value of 11 952.219 s. The velocity of water flow in a channel is not uniform as it is slower at the surface of leaves and faster in the free zones. The maximum velocity is observed in the middle section of the channel, below the leaf, and between the roots with the value of u = 0.1158 m/s. Furthermore, the characteristics of turbulence in a channel are influenced by several factors such as channel geometry, flow velocity, and vegetation distribution. As a result, the presence of vegetation in a channel affects the flow and turbulence characteristics of the water significantly.
- DergiPhysics of Fluids