Numerical Modeling of Hydraulic Jump in Stilling Basin of High Dams

The outflow from dams, due to its huge amount of kinetic energy, can cause damages such as scouring of the riverbed or destruction of the equipment. Stilling basins are structures that dissipate the excess flow energy at downstream of dams. One of the most common methods, which is used in hydraulic structures analysis, is numerical simulation. Most of these methods are based on computational fluid dynamics (CFD. With the capabilities of numerical methods and advanced softwares, complex and diverse modes of action can be investigated. In this research, hydraulic jumps in stilling basin at downstream of a high dam is numerically simulated by using three different turbulence models including the standard K-ε, RNG and LES models and then the results are compared with the experimental data. According to the results, the best turbulence model was LES model for numerical modeling of flow in the stilling basin. In order to evaluate the effect of chute blocks on the performance of stilling basin, a proposed model assuming standard chute blocks of USBR stilling basin type II is considered and this model is compared with the original model. Results showed a decrease of approximately 40% and 4.5% in the flow velocity, respectively, in the beginning of the stilling basin and incident hydraulic jump section on the chute structure, which reflects the high impact of the chute blocks on the improvement of the performance of this dam's stilling basin.