Study On 3d Hydraulic Behavior Of Lateral Damless Canal Head Work

Most of the damless water intakes are lateral, the hydraulic problems near which are very complex, such as easily producing swirl when it shunts, this will not only reduce the streaming capabilities, but also produce a greater head loss. It has important guiding significance for the construction of the project to study damless water intakes'hydraulic characteristics. The CFD numerical simulation technology combined by hydraulics and computer technology greatly enhances the ability to solve complex problems. Compared with model experiments, numerical simulation has advantages that it can be achieved with the complex flow field in ideal condition of all domain simulation, providing a large amount of rich information, can be directly simulated on the prototype without considering similar legal issues. Therefore, it's very necessary to use numerical simulation to improve the understanding of the water intake flow microscopic structures.Large-scale computational fluid dynamics software-FLOW-3D is used in this paper to numerically simulate damless water intake. The numerical simulation results of water intakes of angle 45°and 90°were compared and validated with experimental data results gathered whose good agreement proves the reliability of numerical method. Then this numerical simulation model was used to calculate and analyze the hydraulic characteristics of damless water intake, which comes to conclusions that the larger the lateral canal's diversion angle, the smaller the water diversion ratio and the greater the relevant head loss; the larger the lateral canal's width, the greater the water diversion ratio and the smaller the relevant head loss; the larger the main channel's flow Froude number, the smaller the lateral channel's water diversion ratio and the greater the relevant head loss. The analysis results show that with decreasing of the diversion angle from 90°to 30°, the streamlines are appearing more smooth, the relative diversion width of the main flow upstream of the intake is reducing, the net inflow width in the intake is becoming lager, so that the flow of the entire water area are more conducive to water. The better the water flow conditions near the water intake, the smaller the local resistance coefficient, the smaller the head loss and the larger the water diversion ratio, which helps to improve water efficiency. These research results can be applied to related works, and three-dimensional numerical simulation method can be a powerful supplement to model tests, which can provide reference for studying the hydraulic characteristics of water intake, engineering practice and application and have some guidance on similar projects.