Abstract: As one of the core components of the drip irrigation system, the hydraulic performance of the emitters directly determines the irrigation efficiency of the drip irrigation system. In practical applications, the labyrinth type emitters of the flow rate is too large, which leads to serious water and fertilizer loss, easy to clog the problem. To address these issues, numerical simulation methods were used here to study the flow field characteristics of the complex internal flow channel of the emitters. The influence of the structural parameters such as the height of the flow channel teeth, the angle of the teeth, the depth, the length of the cells, and the clearance at the top of the teeth on the hydraulic characteristics of the emitters was analyzed. A test rig was built to test the hydraulic characteristics of the emitters, and the accuracy of the numerical calculation was verified by comparing the test results with the simulation results. The results indicate that tooth height and tooth angle have minimal influence on flow rate, whereas reducing flow-channel depth and unit length effectively decreases discharge. The small-flow double channels emitter structure that takes into account clogging resistance, improves the clogging resistance by 97.1% and reduces the flow rate by 37.5% compared with the pre-improvement one.

Key words: drip irrigation system, emitters, hydraulic characteristics, small flow rate, anti-clogging