Anti-Clogging Performance Optimization for Shunt-Hedging Drip Irrigation Emitters Based on Water–Sand Motion Characteristics

Abstract

To improve the irrigation quality and anti-clogging performance of the emitter, it is necessary to design and optimize its flow channel structure. The shunt-hedging drip irrigation emitter (SHDIE) flow channel is a new type of flow channel. Using computational fluid dynamics, by setting different conditions (such as particle size and injection position), the motion trajectory of sand particles and flow field distribution characteristics of the shunt-hedging flow channel were simulated. According to the simulation results, a new anti-clogging structural optimization scheme was proposed, and physical experiments verified its feasibility. The results showed that the flow index of the original flow channel (SHDIE1) and optimized flow channel (SHDIE2) were 0.479 and 0.486, respectively, which mainly relied on the shunting and hedging of water flow to energy dissipation. For sand particles with diameters of 0.05, 0.10, and 0.15 mm, the average values of the velocity amplitude ratio, η, were 0.9998, 0.9994, and 0.9991, respectively; the average values of the velocity phase difference, β, were −0.143°, −0.320°, and −0.409°, respectively. A larger sand particle diameter led to worse followability and a higher risk of blocking the channel. When the sand particles collided with the sensitive region of the flow channel, their movement direction would suddenly change, entering the vortex area. After colliding with the sensitive region of edge A, the maximum probability of sand particles entering the vortex area was increased to 87.5%, and then they stayed in the vortex area under the effect of the sensitive regions of edges B and C. After the sensitive regions were removed, the motion trajectories of sand particles became regular and smooth. The optimized flow channel’s (SHDIE2) anti-clogging performance was greatly improved by 60%, with a 1.46% loss of hydraulic performance. This study can provide theoretical support for designing the high anti-clogging emitter.