Comparison of Three Turbulence Models in Predicting the Particle Removal Efficiency of a Sedimentation Tank

Settling mechanisms in sedimentation tanks can be simulated and analyzed using Computational Fluid Dynamics (CFD) techniques. The simulation's accuracy is highly dependent on the type of turbulence model used. The performances of three distinct models, RNG k-ε, Realizable k-ε, and SST k-ω, are evaluated in the current research. A full-scale three-dimensional CFD model of a sedimentation tank is being utilized for the current investigation. Before injecting the particles into the flow field, the clean water is first simulated in the tank without them. Then, the particles are supplied and tracked along their trajectories by the method of the discrete phase model. Comparisons are made between the settling efficiency acquired experimentally from a published work and the settling efficiencies obtained from simulations using the three models. The predicted settling efficiencies are 45.48% for RNG k-ε, 40.10% for Realizable k-ε, and 40.16% for SST k-ω, while the experimental settling efficiency is 42.67%. It is observed that all the findings obtained from the simulations are close to the experimental value. When compared to the other two turbulence models, the settling efficiency determined by the SST k-ω yields the most accurate and consistent results.