Numerical modeling of flow in side channel spillway using ANSYS-CFX

Abstract EN

Side channel spillway is one of the most common types of spillways provided at earth dams to release flood discharge laterally.

flow in side channel is complex due to discharge changing along its length.

due to rapid advent of computer technology computational fluid dynamics (CFD) is extensively used to model and analyze complex issues in engineering problems.

in the present study ANSYS-CFX code has been used to predict flow characteristics in the side channel spillway.

grid dependence study provided to select the optimum grid size that can predict free surface profile accurately with minimum computational time.

in addition, various turbulence models such as k- ε and rng k- ε were used.

the capability of each turbulence model to predict flow characteristics in the spillway were tested.

the k- ε and rng k- ε turbulence models gives good results at most parts of the spillway, while rng k- ε turbulence model needs higher computational time.

furthermore, the ability of the code to predict free surface water profile for various discharges was validated using results of the physical model.

the comparisons of water surface profile predicted by ANSYS-CFX with the physical model show good agreement.

Unlikely, at the location of hydraulic jump in the stilling basin for higher discharges which characterized by strong aeration ANSYS-CFX with k- ε turbulence model failed to give accurate predicts of the free surface water profile.