Water distributions of low-pressure sprinklers as affected by the maize canopy under a centre pivot irrigation system

Hui, Xin; Zheng, Yudong; Yan, Haijun

doi:10.1016/j.agwat.2020.106646

Cited by 19 publications

(5 citation statements)

References 31 publications

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“…By the end of 2019, it was estimated that approximately 18 000 centre pivot and linear move irrigation systems were in use throughout the country. The corresponding irrigated area was approximately 0.6 million ha, accounting for 14.2% of the total sprinkler-irrigated area of China (Hui, Zheng, et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Comprehensively evaluating and modelling droplet diameters and kinetic energies of low‐pressure sprinklers

Hui

Zheng

Meng

et al. 2022

Irrigation and Drainage

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Proper droplet diameter and kinetic energy can effectively reduce the risk of soil erosion during low-pressure sprinkler irrigation. In this study, we comprehensively evaluated the radial distributions of droplet diameter, velocity, kinetic energy, kinetic energy per unit droplet volume, and specific power for three common low-pressure sprinklers, i.e. Nelson D3000, R3000 and Komet KPT, with two operating pressures (103 and 138 kPa) and three nozzle outlet diameters (3.97, 5.95 and 7.94 mm). Additionally, the relationships between these droplet characteristic parameters were analysed. Overall, the maximum values of five characteristic parameters were observed at the end of the jet under various treatments. Although R3000 had a larger droplet diameter (0.10-6.42 mm) and kinetic energy (1.08 Â 10 À10 -8.59 Â 10 À3 J) distribution range than D3000 and KPT, the D3000 specific power (mean value of 0.4274 W m À2 ) was the highest of the three sprinklers. Therefore, KPT was suggested more in low-pressure sprinkler irrigation than in the other two sprinklers because its application rates were reduced along the radial direction. In addition to selecting a suitable sprinkler type for minimizing specific power, determining a reasonable sprinkler spacing was also significant (P < 0.01). Furthermore, a universal specific power model with an appropriate accuracy (RMSE = 0.011 W m À2 , NRMSE = 29%) was proposed. This study provides a key basis for the selection and combination of low-pressure sprinklers.droplet diameter, kinetic energy, low-pressure sprinklers, specific power, universal model Résumé Un diamètre de gouttelettes et une énergie cinétique appropriés peuvent réduire efficacement le risque dérosion des sols lors de l'irrigation par aspersion à basse pression. Dans cette étude, nous avons évalué de façon complète les distributions radiales du diamètre des gouttelettes, de la vitesse, de l'énergie cinétique, de l'énergie cinétique par unité de volume des gouttelettes, et de la puissance spécifique pour trois sprinklers courants à basse pression, à savoir Nelson D3000, R3000 et Komet KPT, avec deux pressions de fonctionnement (103 et 138 kPa) et trois diamètres de sortie de la buse (3,97, 5.95 et 7.94 mm). De plus, Article title in French: Evaluation et modélisation complètes des diamètres de gouttelettes et des énergies cinétiques des sprinklers basse pression.

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Section: Introductionmentioning

confidence: 99%

Comprehensively evaluating and modelling droplet diameters and kinetic energies of low‐pressure sprinklers

Hui

Zheng

Meng

et al. 2022

Irrigation and Drainage

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“…Recently, the use of center pivot has led to gradual replacement of medium-and high-pressure sprinklers with low-pressure sprinklers to minimize the energy requirement of the system. The low-pressure sprinklers are commonly classified into three types, namely the fixed spray plate sprinkler (FSPS), rotating spray plate sprinkler (RSPS), and oscillating spray plate sprinkler (OSPS) (Manke et al, 2019;Hui et al, 2021b). The different structures and operating modes of these three types of sprinkler result in significant differences in their performances.…”

Section: Introductionmentioning

confidence: 99%

Non-negligible factors in low-pressure sprinkler irrigation: droplet impact angle and shear stress

et al. 2022

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Droplet shear stress is considered as an important indicator that reflects soil erosion in sprinkler irrigation more accurately than kinetic energy, and the effect of droplet impact angle on the shear stress cannot be ignored. In this study, radial distribution of droplet impact angles, velocities, and shear stresses were investigated using a two-dimensional video disdrometer with three types of low-pressure sprinkler (Nelson D3000, R3000, and Komet KPT) under two operating pressures (103 and 138 kPa) and three nozzle diameters (3.97, 5.95, and 7.94 mm). Furthermore, the relationships among these characteristical parameters of droplet were analyzed, and their influencing factors were comprehensively evaluated. For various types of sprinkler, operating pressures, and nozzle diameters, the smaller impact angles and larger velocities of droplets were found to occur closer to the sprinkler, resulting in relatively low droplet shear stresses. The increase in distance from the sprinkler caused the droplet impact angle to decrease and velocity to increase, which contributed to a significant increase in the shear stress that reached the peak value at the end of the jet. Therefore, the end of the jet was the most prone to soil erosion in the radial direction, and the soil erosion in sprinkler irrigation could not only be attributed to the droplet kinetic energy, but also needed to be combined with the analysis of its shear stress. Through comparing the radial distributions of average droplet shear stresses among the three types of sprinklers, D3000 exhibited the largest value (26.94-3313.51 N/m 2 ), followed by R3000 (33.34-2650.80 N/m 2 ), and KPT (16.15-2485.69 N/m 2 ). From the perspective of minimizing the risk of soil erosion, KPT sprinkler was more suitable for low-pressure sprinkler irrigation than D3000 and R3000 sprinklers. In addition to selecting the appropriate sprinkler type to reduce the droplet shear stress, a suitable sprinkler spacing could also provide acceptable results, because the distance from the sprinkler exhibited a highly significant (P<0.01) effect on the shear stress. This study results provide a new reference for the design of low-pressure sprinkler irrigation system.

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“…One defines the fundamental parameters of the system in this hydraulic design, creating a knowledge brocade. The number of spans, regulators and the count of sprinklers adorning each span all find their place within the dataset [32]. But beyond mere numbers, the dataset bears the imprint of hydraulic forces, offering a chronicle of pressures spanning from the inaugural span to the valedictory span in each pivot.…”

Section: Structure Of the Cpis In Irriexpress Softwarementioning

confidence: 99%

Sustainable Water Management for Small Farmers with Center-Pivot Irrigation: A Hydraulic and Structural Design Perspective

Rashid,

Haider,

Masood

et al. 2023

Sustainability

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In Pakistan, surface water supply for irrigation is decreasing, while water demand is increasing for agriculture production. Also, due to the fast rate of population growth, land holding capacity is decreasing. So, there is a need to develop appropriate technologies and design approaches for small-scale farmers to improve modern irrigation practices. In this study, a hydraulic and structural layout of CPIS was designed for small-scale farmers with some modifications. The hydraulic parameters and structural design of the CPIS were designed using IrriExpress and SAP2000 software, respectively. An economic analysis of the modified CPIS was carried out. The results revealed that in one complete revolution of the whole system, its span slope varied from 2.98 to 0.1%, and the wheel slope varied from 2.35 to −2.4%. The timing setting was 60% for one revolution, and the irrigation depth was 10 mm. When the time setting was reduced from 100% to 10%, the irrigation hours per cycle and irrigation depth both increased. Variendeel type-II trusses were designed for structural purposes using SAP2000 software. This design led to a 17% reduction in weight by lowering it from 1.916 to 1.5905 tons and a 44% reduction in joint count, decreasing it from 32 to 18. Our economic analysis revealed that the structural part of the system is more expensive than the hydraulic, electric and power parts for small-scale design. So, it was suggested that CPIS is suitable for land holdings from 100 to 250 acres, because when the area increases to more than 250 acres, there is no significant change in the cost. A towable system is more economical for small-scale farmers due to its lower cost per acre. This study will be helpful for the optimization of CPISs to improve water use efficiency and crop yield.

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Water distributions of low-pressure sprinklers as affected by the maize canopy under a centre pivot irrigation system

Cited by 19 publications

References 31 publications

Comprehensively evaluating and modelling droplet diameters and kinetic energies of low‐pressure sprinklers

Comprehensively evaluating and modelling droplet diameters and kinetic energies of low‐pressure sprinklers

Non-negligible factors in low-pressure sprinkler irrigation: droplet impact angle and shear stress

Sustainable Water Management for Small Farmers with Center-Pivot Irrigation: A Hydraulic and Structural Design Perspective

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