引黄滴灌灌水器流道水流模拟及堵塞成因研究

Study on Flow Simulation and Clogging Cause of Drip Emitters in Yellow River Diversion Project

为探究大田引黄滴灌系统灌水器流道的堵塞机理,以减少大田灌水器系统堵塞,根据山西运城尊村灌区泥沙特点利用SolidWorks绘图软件进行灌水器流道的建模设计,以大田滴灌实际工程条件设置仿真参数,采用Ansys Fluent仿真软件进行不同型号灌水器流道的仿真计算模拟。研究此灌水器的压力、流速、湍动能等湍流特性以及颗粒的运动轨迹,揭示其内部流动机理。灌水器内部流体域压力随流道单元线性降低,并且压降梯度与流道单元数量线性相关;主流区流体更新快,泥沙不易发生沉积,流道旋涡区以及储水槽倒角部位是泥沙发生沉积的主要部位;流道高速区以外的其他区域以及储水槽部位整体湍流动能较低,水流无法形成或维持湍流状态,不利于泥沙运移,从而形成堵塞。模拟结果表明,灌水器内部结构流体域流速、湍流动能以及流线等分析均表明在灌水器流道部分的低速区和储水槽部位的倒角和边壁处是发生泥沙颗粒沉积的主要部位。

In order to study the clogging mechanism of the drip irrigation system of Yellow River diversion in the field,and to reduce the clogging of the irrigation system in the field,based on the characteristics of sediment in Zuncun irrigation district of Yuncheng,Shanxi Province,SolidWorks is used to model and design the flow path of emitters.The simulation parameters were set according to the actual engineering conditions of drip irrigation,and Ansys Fluent simulation software is used to simulate the flow passage of different types of emitters.The turbulent characteristics such as pressure,velocity and turbulent kinetic energy of the emitters,as well as the particle trajectories are studied to reveal the internal flow mechanism of the emitters.The pressure of the fluid basin inside the emitters decreases linearly with the flow channel units,and the pressure drop gradient is linearly related to the number of flow channel units.The fluid in the mainstream area is updated quickly,and is not prone to sedimentation.The vortex area of the flow channel and the chamfered parts of the storage tank are the main parts where sedimentation occurs.The turbulent kinetic energy is lower in the vortex region of the channel and the chamfering part of the water storage tank than in the other regions of the channel,so the turbulent flow can not be formed or maintained,which is not conducive to sediment transport,thus forming a plug.The simulation results show that,the analysis of flow velocity,turbulent kinetic energy and streamline in the inner structure of the emitters shows that the low velocity zone and the chamfer and side wall of the storage tank are the main locations of sediment deposition in the emitters.