Affiliation:
1. School of Hydraulic and Electric Power, Heilongjiang University, Harbin 150080, China
2. Heilongjiang Academy of Black Soil Conservation and Utilization, Harbin 150086, China
Abstract
Leaf vein drip irrigation emitter is a new type of drip irrigation emitter. The flow channel achieves energy dissipation through flow diversion, turning, and sudden contraction. In this study, three design schemes (B1, B2, and B3) were proposed by optimizing the flow channel structure to improve the hydraulic performance, and the feasibility of the schemes was verified by combining them with experiments. The results show that the flow index of the three structural optimization designs were 0.52, 0.51, and 0.50, with errors of less than 5% compared to the measured results. Compared to the original structure A1 (with a flow index of 0.53), the hydraulic performance was improved by 0.4%, 3.2%, and 5.7%. Compared with A1 and B1, the turbulence kinetic energy of the main flow region of the B2 and B3 structures was significantly increased, and the proportion of low turbulence kinetic energy area had decreased. The increase in turbulent kinetic energy drove the liquid to remain turbulent, increasing the ability of particulate matter to flow out of the flow channel. The irregular changes in the velocity field in the high-speed zone result in a large velocity gradient, which maximizes the turbulent kinetic energy and entropy generation in the area. Among the four flow channel structures, the region with the highest turbulence dissipation was located in the upper part of the internal structure of the flow channel. There were apparent vortex regions in flow channels A1, B1, and B3 for energy dissipation, with energy dissipation coefficients being 6.07–8.51. However, the average flow velocity in this region was only about 0.2 m/s, and particulate matter was easily trapped. When the particle diameter increased, compared with the other three design structures, B2 had the best particle passage ability. Combined with the muddy water experiment, the optimized flow channel B2 anti-clogging performance improved by 30.8%. This study can provide a reference for further improving the hydraulic performance of drip irrigation emitters.
Funder
Basic Scientific Research Fund of Heilongjiang Provincial Universities
Reference37 articles.
1. Clogging investigation of pressure compensating button emitters: An experimental study of four types;Ouarriche;Environ. Sci. Pollut. Res.,2020
2. Development situation and system construction of low-carbon environment friendly drip irrigation technology;Li;Trans. Chin. Soc. Agric. Mach.,2016
3. A 2020 vision of subsurface drip irrigation in the US;Lamm;Trans. ASABE,2021
4. Analysis on hydraulic performance of bidirectional flow channel of drip irrigation emitter;Tian;Trans. Chin. Soc. Agric. Eng.,2013
5. Experimental study on flow characteristics in labyrinth path emitters;Li;J. Hydraul. Eng.,2005