A CFD-Based Simulation Study of a New Type of Sediment Basin for the Yellow River.

Because of the high sediment content and fine sediment particles in the Yellow River, it is easy to cause the clogging problem of the emitter in the drip irrigation system. In view of this problem, a new type of sediment basin composed of gravity sedimentation structure and screen filter structure is proposed in this study，its key structure is pipe chute and screen filter. In order to improve the sedimentation efficiency of settling basin for the Yellow River, A computational fluid dynamics model coupled with discrete element method(DEM-CFD) is presented here to simulate flocculation and sedimentation process of cohesive fine sediment. With this method, the structural parameters such as the length, angle of pipe chute and layout area and angle of screen filter are determined, the position of accessory structure of sediment basin such as adjusting flow wall, overflow gutter and sand funnel are also confirmed. The numerical simulation results are validated with full-scale measurements at the Yellow River irrigation districts Dengkou experimental establishment. It is found that the pipe chute can increase the sediment removal efficiency by 20%-30%, its suitable length and proper layout angle for drip irrigation system in the Yellow River water are 60-80cm and 60°，respectly. With the correct layout of accessory structure ，the new type of sediment basin proposed in this study can significantly improve the sediment removal efficiency in different working conditions， comparing with the traditional sand basin, the total sediment removal efficiency proposed in this study can be increased by 30%-40%.