Influence of Dentation Angle of Labyrinth Channel of Drip Emitters on Hydraulic and Anti‐Clogging Performance

Abstract

The geometric parameters of labyrinth channels play an important role in the hydraulic and anti‐clogging performance of drip emitters. In this study, the flow fields, individual representative sands and sand groups in the labyrinth channel of emitters, with dentation angles of 90°, 60°, 45° and 30°, were firstly simulated using a computational fluid dynamics discrete element method (CFD–DEM) of coupling. Particle tracking velocimetry (PTV) was used to trace individual representative sands. The numerical results were verified with clear water hydraulic performance tests and muddy water anti‐clogging performance tests. The results suggest that the discharge coefficient and flow exponent declined when the dentation angle of the labyrinth channel was reduced. A large number of sand groups were observed to enter the vortex areas and move in a circular manner. The time it took for particles to pass through the labyrinth channel lengthened when the velocity decreased and as a result, the probability of emitter clogging increased. Therefore, by using a recommended angle range of 90° to 60° and a combined higher hydraulic performance level, emitters were less likely to clog. It was a novel approach to adopt a CFD–DEM coupling method to conduct numerical analysis of individual sand particles and sand groups in the investigation of emitter anti‐clogging issues. The findings will increase the design efficiency of flow channels and will save human and material resources. © 2018 John Wiley & Sons, Ltd.

Prediction of Pressure–Discharge Curves of Trapezoidal Labyrinth Channels from Nonlinear Regression and Artificial Neural Networks

“…These devices are installed along polyethylene pipes (i.e., the lateral lines) and are responsible for controlling the discharge to apply water evenly on the soil (Frizzone et al 2012). Drippers designed based on labyrinth channels commonly are used in drip irrigation systems due to their low cost, simple structure, and efficient hydraulic performance (Yu et al 2019;Zhang et al 2010). A labyrinth consists of a narrow channel with several baffles that generate head losses and ensure discharge regulation (Al-Muhammad et al 2018;Wei et al 2006;Zhang et al 2016).…”

“…The geometric parameters (i.e., dimensions and shape) of labyrinth channels are critical for hydraulic performance and the resistance of drippers to clogging (Feng et al 2018;Haosu et al 2016;Wei et al 2006;Yu et al 2019;Zhang et al 2013). The resistance of drippers to clogging (i.e., anticlogging performance) relies on the drippers' design and the water quality.…”

Influence of Flushing Pressure before Irrigation on the Anti‐Clogging Performance of Labyrinth Channel Emitters

“…In north-west China, especially in the Yellow River irrigation district, the surface and underground waters contain large amounts of tiny particles. Although deposition and filtration (120 meshes) techniques are adopted, fine sand particles smaller than 100 μm in diameter can still get into emitters and cause clogging (Wei et al, 2006a, b;Yu et al, 2011). Many previous studies have focused on this issue.…”

The Development of a Calculation Model for the Instantaneous Pressure Head of Oscillating Water Flow in a Pipeline

“…As such, it is difficult to ensure the quality of the irrigation spray is good [10,11].In order to solve the problem of clogging in an emitter, earlier studies conducted experiments to investigate the influence of flow passage geometry parameters on the hydraulic characteristics of the emitter. Based on the experimental results, the flow passage of the emitter was optimized so as to improve the anti-clogging performance of the emitter under low pressure [12][13][14][15]. In order to improve the spraying effect of the sprinklers under low pressure, auxiliary sprinklers, jet devices, and water dispersing devices can be added or the original sprinklers can be replaced with non-circular sprinklers [16][17][18].…”