【作者】 李连杰； 唐学林； 李云开； 李小芹；

【Author】 Li Lianjie;Tang Xuelin;Li Xiaoqin;College Of Water Resources And Civil Engineering, China Agricultural University;Beijing Engineering Research Centre of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University;

【机构】 中国农业大学水利与土木工程学院； 北京市供水管网系统安全与节能工程技术研究中心；

【摘要】 为了更好的研究齿形迷宫流道的内流场水力性能和滴头的抗堵塞性能,该文采用雷诺应力模型和Eulerian-Lagrangian两相流模型对迷宫流道进行了一系列数值研究。首先,通过基于两种湍流模型(标准k-ε与雷诺应力模型)预测齿形迷宫流道滴头的水力性能,并与文献[18]的试验结果对比分析,采用雷诺应力模型计算的结果与试验结果更为接近。然后,基于Lagrangian的颗粒离散相模型,数值研究了不同工作压力下齿形迷宫流道内单个颗粒和多颗粒的运动轨迹及运动特性,并与文献[17]试验结果进行对比分析,结果表明工作压力越大,颗粒的进入漩涡区的次数越少,运动越有规律;随着颗粒直径增大,颗粒进入漩涡区的个数和次数均减小,颗粒运动开始变得有规律,明显跟随主流区运动;随着颗粒密度的增大,颗粒跟随主流区运动的能力减弱,但颗粒更容易回到主流区。最后,研究了在不同压力水头下迷宫流道颗粒的通过率,结果表明迷宫流道的颗粒通过率基本随工作压力的增大而增大。同时,以上对比分析表明,相关两相流模型和数值方法可很好预测滴头内部固液两相流动,可为滴头抗堵塞设计提供参考。更多还原

【Abstract】 In order to better study the hydraulic performance of the flow field inside the toothed labyrinth and the anti-clogging performance of the dripper, a series of numerical studies on the labyrinth channel were carried out based on the Reynolds stress model and the Eulerian-Lagrangian two-phase flow model. Firstly, the hydraulic performance of the toothed labyrinth channel dripper is predicted based on two turbulence models(standard k-ε and Reynolds stress model), and compared with the experimental results in literature [18], the results calculated by the Reynolds stress model are closer to experimental data. Then, based on Lagrangian particle discrete phase model, the trajectories and motion characteristics of single particles and multi-particles in the labyrinth flow channel under different working pressures are numerically simulated and compared with the experimental results in literature [17]. The results show that with the increase of the working pressure, the particle enters the vortex zone less, and the motion of particle goes back to regular; with the increase of particle diameter, the number of particles and the times of particles entering the vortex zone decrease, and the particle motion begin to become regular, obviously following the mainstream; as the density of the particles increases, the ability of the particles to follow the movement of the mainstream zone is weakened, but the particles are more likely to return to the mainstream. Finally, the percentage of the particles passing the labyrinth flow channel under different pressure heads was studied. The results show that the percentage of the escaped particles increases with the increase of the working pressure. At the same time, the above comparative analysis shows that the relevant two-phase flow model and numerical method can well predict the solid-liquid two-phase flow inside the dripper, which can provide reference for the anti-clogging design of the dripper.更多还原