Document Type : Research Paper
Department of civil engineering, Estahban Branch, Islamic Azad University, Estahban;
Department of Civil Engineering, Islamic Azad University, Estahban Branch, Fars, Iran.
Associate Professor, Isfahan Univ. of Technology (IUT), Isfahan, Iran
Hydraulic jump is used as an important energy dissipator phenomenon downstream of hydraulic structures such as spillways, gates and chutes. The innovation of this research is the use of divergent-convergent stilling basins to reduce the cost and increase the performance of the stilling basins. All experiments were performed in a channel with a length of 11.0 m, depth of 0.7 m and width of 0.48 m. The results of the divergent-convergent stilling basin were compared with the classic and divergent basins as well as previous research. The results indicate that in the divergent-convergent basin, the depth ratio (y2/y1) and jump length (Lr/y1) decreased by 29.06% and 90.44% compared to the classical basin, respectively, while the reduction of these values for divergence basin is just by 3.25% and 37.92 %, respectively. Furthermore, the energy loss in divergent-convergent and divergent basins has increased by 25.99% and 23.38%, respectively. Finally, several equations were recommended to predict the ratio of conjugate depths and jump length using dimensional analysis and two analytical and regression methods. In light of this study, it can be concluded that divergent-convergent settling basins with smaller dimensions and greater energy loss are much more suitable alternatives to classical and divergent basins.