Vertical optimisation of tooth shape to improve the anti-clogging performance of emitters in drip irrigation systems

Emitter clogging greatly affects the efficiency and lifespan of drip irrigation systems. Numerical simulations and experimental tests were used to investigate the effects of four tooth designs on the emitter flow characteristics and anti-clogging performance. The four tooth designs included a symmetrical tooth-shaped structure (STS); teeth with vertical upstream surfaces opposite to teeth with vertical downstream surfaces (UDV); symmetrical teeth on one side with vertical upstream surfaces on the other (OUV); and teeth on both with vertical upstream vertical surfaces (BUV). The BUV channel had the greatest flow coefficient and flow rate and there was no significant effect on the emitter discharge exponent (P > 0.01). Compared with the STS channel, vertical adjustment of the upstream surfaces can significantly reduce the proportion of the channel occupied by low-velocity and low turbulent kinetic energy (TKE) zones and increased the proportion of the channel occupied by high-velocity and high-TKE zones. By contrast, vertical adjustment of the downstream surface resulted in non-optimal low-velocity and dead-angle zones. In the BUV channel, the high-speed zone accounted for 39.85% of the channel area, with a maximum flow velocity of 3.192 m s(-1). The high-TKE zone accounted for 66.09% of the channel area, with a maximum TKE of 1.681 m(2) s(-2). These results increased by 7.01%, 6.22%, 15.65%, and 52.40% compared to the STS channel, respectively. Furthermore, particles have the highest escape rate in BUV channel, reaching 100%, and the minimum escape time in only 0.3 s. Therefore, BUV channel had the best effect for improving the anti-clogging performance of emitter. (c) 2023 IAgrE. Published by Elsevier Ltd. All rights reserved.