Analysis of anti-clogging performance and particle transport characteristics of a stellate irrigation emitter

The service life and irrigation efficiency of drip irrigation systems are largely determined by the anti-clogging performance of the emitters. The degree and speed of clogging of the emitters are governed by the motion state of the particles in the flow channel. Computational fluid dynamics coupled discrete element method (CFD-DEM) and experiments were used to analyse anti-clogging performance and particles transport characteristics of a stellate irrigation emitter. With the angle of repose of sediment particles as the optimization objective, the key parameters of physical properties of sediment particles and container were obtained in the discrete phase model using a Plackett-Burman test, steepest climb test and Box-Behnken test. A novel evaluation method for assessing anti-clogging performance based on particles mass passing rate is proposed and its accuracy experimentally verified. Using three particles groups with different particle size distributions, the anti-clogging performance of stellate emitter was found to better than the widely used toothed emitter. In particular, the anti-clogging performance of the stellate emitter was found to be superior with the sensitive particle size of 0.03 mm. It was shown that sediment particles demonstrated retention, bonding and deposition in the inlet far away from the flow channel, the backwater area at the vertical vertex of the stellate structure and the backwater area at the joint of the stellate emitter flow channel structure units.