Turkish Journal of Hydraulic, vol.9, no.2, pp.49-58, 2025 (Peer-Reviewed Journal)
The research aims to identify the
optimal turbulence model and mesh size for achieving close agreement between
numerical and experimental results, contributing to the improvement of CFD
applications for stilling basin design. This
study simulates the velocity distribution of hydraulic jumps in a stilling
basin with a smooth bed, under flow rates of 33–60 L/s and Froude numbers of 7–10.
Four turbulence models—RNG, k-ε, k-ω, and LES—were evaluated to
determine the most accurate model by comparing numerical results with
experimental data from a 10 m long, 0.51 m wide laboratory flume. A mesh
convergence study identified an optimal mesh size of 0.011 m, balancing
accuracy and computational efficiency. The RNG turbulence model demonstrated
superior performance, with the lowest relative error (RE = 5.41%) and absolute
error (AE = 0.0065 m) for hydraulic head predictions, attributed to its
robustness in capturing high-shear flows. These findings enhance the
application of CFD in optimizing stilling basin designs for hydraulic
structures.