Hydrodynamic characteristics of lateral withdrawal with effects of the slope ratio

Abstract

Lateral withdrawal is widely performed in water transfer and water supply projects. Hydrodynamic characteristics of intake are crucial to safe and stable operation. In this study, a 3-D numerical volume of fluid model was established and validated through experimental tests. Hydrodynamic characteristics and secondary flow were investigated under scenarios with the vertical slope and different slope ratios. The helix-shaped recirculation and surface vortex are generated, and the secondary flow near the surface layer is more serious. Adding a slope ratio is beneficial to improve the flow patterns and recirculation, while the surface vortex width increases. Additionally, with the decrease in the slope ratio, recirculation width and the ratio of recirculation to the width of the layer decrease, and the minimum values are 9.19 cm and 22.97%, respectively. However, the lower the slope ratio is, the greater recirculation inhibition affects are, and the more serious the surface vortex is. With the decrease in the slope ratio, the widest surface vortex width and the ratio of the widest surface vortex to the width of the layer increase from 6.1 to 12 cm and from 7.82 to 17.14%, respectively. This research represents an advance in lateral withdrawal and provides support for further designs.