迷宫型灌水器水沙两相流场分析及结构改进

为了解决迷宫型灌水器微细流道容易堵塞的问题，针对其复杂的微细流道结构(实际尺寸在0.8～1.2 mm之间)，根据灌水器工作时灌溉水中存在过滤不掉的沙粒的实际情况，首先应用计算流体力学(Computational fluid dynamics, CFD)数值计算的方法，进行灌水器整体迷宫流道水砂两相流数值模拟，根据其流动场分析其堵塞的结构因素。同时应用粒子图像测速(Particle image velocimetry, PIV)技术，搭建灌水器流道流动场微PIV测试台，测量实际尺寸大小的微流道中流动场和粒子运动状况，得到其流动场流线图和粒子运动轨迹图，并通过灌水器的抗堵塞性能试验，验证了迷宫型灌水器微流道中流动场和粒子状况分析计算的正确性。针对流道中存在的容易引起堵塞的流动滞止区进行结构优化改进，试验结果表明，应用改进的结构可提高迷宫型灌水器的抗堵塞性能。

Visualized Experimental Analysis of Water-sand Flow Behaviors for Labyrinth Emitters

In order to solve the clogging problem of labyrinth channels in drip emitters, aiming at the complex structure of mini-channels (actual size between 0.8～1.2 mm), the emitters are easily clogged by sands which cannot be filtered in irrigation water. Depending on the practical conditions of emitters, the computational fluid dynamics (CFD) is utilized to conduct the numerical simulation of two-phase flow and hence visually reveal clogging reasons by analyzing the water-sand flow behaviors in the channels of emitters. Based on particle image velometry (PIV) technology, the Micro-PIV test bed is set up. The conditions of water flow and particles movement are measured, and the water flow path graph and particle path graph are obtained. Then the CFD computational results are verified through clogging experiments. On this basis, the anti-clogging mechanism is analyzed, and the channel structure in the stagnant areas is optimized.