Numerical simulation of flow velocity profiles along a stepped spillway

The velocity profiles on stepped spillways are analyzed using computational fluid dynamics simulations and large-scale laboratory experiments. Five different turbulence models are considered in the analysis: the Standard k-ɛ, the Realizable k-ɛ, the Renormalization group k-ɛ, the Standard k-ω and the Shear stress transport k-ω model. The computational fluid dynamics simulation results are compared with laboratory measurements from a large-scale physical model with flow velocities up to 15 m/s. It is indicated that the numerical model involving any of these turbulence models can satisfactorily simulate the velocity profiles. All five turbulence models performed satisfactorily well on large-scale stepped spillways. The k-ω models may be slightly better suited in the lower region, while the realizable k-ɛ model provided slightly better results in the upper part of the velocity profile. A power law with n = 5.09 also provides a useful first approximation with a limitation of the flow along stepped spillway with the Reynolds number of 1 . 68 × 10 6 ≤ Re ≤ 7 . 21 × 10 6 .