Effect of riser height on rotation uniformity and application rate of the dynamic fluidic sprinkler

Abstract

The objective of this paper was to investigate the effect of riser heights on rotation uniformity and application rate of the newly designed dynamic fluidic sprinkler. The dynamic fluidic sprinkler was tested using different nozzle sizes of 5 and 6 mm. The sprinkler head was mounted on 1.3, 1.5, 1.7 and 1.9 m risers at 90 in the horizontal direction and was placed about 0.9 m above the top of the cans. The following operating pressures were tested: 150 and 200 kPa. A program was written to simulate the non-uniform of rotation of the nozzle during the full circle-spraying process. It was found that the riser height had a significant effect on application rate and uniformity. The comparison of standard deviation with different risers showed that differences in standard deviation were much lower for the 1.9 m riser height. The deviation was in the range of 0.14~0.26, 0.14~0.42, 0.18~0.50 and 0.13~0.69 mm h −1 considering the riser heights of 1.9, 1.7, 1.5 and 1.3 m. For all the nozzle sizes, a smaller standard deviation was recorded under 150 kPa. The deviation range was 0.15~0.24, 0.17~0.45, 0.18~0.45 and 0.2~0.66 mm h −1 for 1.9, 1.7, 1.5 and 1.3 m, respectively. With respect to nozzle sizes, 5 mm gave better standard deviations and the deviation range was from 0.14~0.26, 0.15~0.45, 0.2~0.7 and 0.23~0.74 mm h −1 with radial heights of 1.9, 1.7, 1.5 and 1.3 m, respectively. The range of the coefficient of uniformity values for overlapped quadrants for the 5 mm nozzle was as follows: 78% at a spacing of 10 to 72% at 80% overlapped spacing. The highest occurred at 50% spacing and increased with an overlapped spacing of 10 to 50%, ranging from 78 to 87% with an average of 82.5%.

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

“…The water application rate of each measuring point refers to the depth of sprayed water falling into the catch can per unit of time (Fordjour et al, 2020) and was calculated as follows: where P w is the water application rate, mm h −1 ; M is the weight of water collected in the catch can, g; A is the opening area of the catch can, mm 2 ; and T is the test duration, h.…”

“…where V is the resultant velocity of the water droplet, m s À1 ; V v is the vertical velocity of the water droplet, The water application rate of each measuring point refers to the depth of sprayed water falling into the catch can per unit of time (Fordjour et al, 2020) and was calculated as follows:…”

Effects of the depth of the needle‐shaped water dispersion device inserted into the jet on the jet breakup of sprinklers

“…The sprinkler water application rate is defined as the spraying water depth per unit time (Fordjour et al, 2020), and in this study, it was obtained by averaging the water application rate of each measuring point of the seven radial lines under the same radius: where P is the sprinkler water application rate at a specific radius (mm/h), h i is the precipitation depth at that radius and the i ‐th radial line (mm), and t is the rotation time of the sprinkler head ( h ).…”

Optimization and numerical simulation of the internal flow field of water–pesticide integrated microsprinklers

“…The advantages of the wide application of water–pesticide integrated irrigation technology include water savings, minimizing pesticide consumption, increasing crop yield and quality and improving the soil environment. With the advantages of high efficiency, water and pesticide savings and precise irrigation, water–pesticide integration technology has become a valuable water‐saving irrigation technology in China (Fordjour et al, 2020; Liu, Liu, et al, 2016; Prabakaran et al, 2018; Zhu et al, 2016).…”