Abstract: 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.

Key words: Labyrinth emitters, Mini-channel, Particle image velocimetry, Two-phase flow of water and sand