Effects of Pressure and Nozzle Size on the Spray Characteristics of Low-Pressure Rotating Sprinklers

Abstract

Using low-pressure sprinklers in agricultural irrigation has become an alternative way of reducing water and energy stress. To determine the applicability of the low-pressure rotating sprinkler, an experiment was conducted to evaluate the effects of working pressure and nozzle size on sprinkler rotation speed, application rate, droplet size, droplet velocity, droplet trajectory angle, and kinetic energy distribution. The results showed that the mean droplet diameter increased exponentially along with the increase in distance from the sprinkler, and a logarithmic relation was derived between droplet diameter and droplet velocity. Due to the low breakup degree of the jet under the lowest working pressure of 100 kPa, the peak values of specific power and application rate were high, which reached 0.09 W m−2 and 11.35 mm h−1, and were 3.1–5.4 times and 2.5–3.1 times those of other working conditions. Meanwhile, the peak specific power of the biggest nozzle (diameter = 5.2 mm) was 2.4–2.8 times that of smaller nozzles. With an increase in working pressure, the sprinkler time per rotation decreased and the distributions of kinetic energy and water became more uniform. Thus, it is not recommended to equip the sprinkler with a large nozzle under low working pressure.

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

“…Fixed spray plate sprinklers (FSPSs), rotating spray plate sprinklers (RSPSs) and oscillating spray plate sprinklers (OSPSs) can be classified as low‐pressure sprinklers with specific designs and operating conditions (Manke et al, 2019). Numerous studies have shown that RSPSs have higher energy consumption in addition to having a wide spraying range, low wind drift, evaporative losses and a relatively uniform distribution of water (Chen et al, 2020; Faci et al, 2001; Hills & Barragan, 1998). The cost of an FSPS was lower than that of an RSPS, but this sprinkler type attained high instantaneous application rates and poor application uniformity, which caused soil and water loss (Silva, 2007; Yan et al, 2011).…”

Experimental Study on Droplet Characteristics of Rotating Sprinklers with Circular Nozzles and Diffuser

“…This is because the rapid decrease of AR led to the decrease of the SP value. According to the general situation, the peak value of SP appears only when the droplet diameter, velocity, and AR remain at a high level [15]. However, due to the special structure of the Nelson R33 sprinkler used in this study, the device used to aggravate the droplet breakage was added, which significantly reduced the impact of working pressure on the droplet characteristics.…”

“…Issaka et al [14] studied the effects of different forms of diffusers on jet breaking through the combination of high-speed photography experiments and computational fluid dynamics simulations to obtain better structural parameters. Chen et al [15] determined the spray characteristics of a low-pressure rotating non-circular sprinkler with a diffuser. However, commercially available low-pressure rotating sprinklers with diffusers are scare.…”

Drop Size Distribution and Effective Determination of the Constitution of Throughfall Droplets under Maize Canopy

“…[1] Sprinkler irrigation technology, a relatively modern irrigation method used by farmers to improve irrigation efficiency, water and fertilizer use, and crop yield and quality, has been widely promoted and applied worldwide. [2] However, sprinkler irrigation also plays an important role on irrigation-based erosion. [3,4] Energy-carrying water droplets produced by sprinkler irrigation systems can essentially describe the critical mechanism of DOI: 10.1002/clen.202100280 soil particle transport.…”

“…[ 1 ] Sprinkler irrigation technology, a relatively modern irrigation method used by farmers to improve irrigation efficiency, water and fertilizer use, and crop yield and quality, has been widely promoted and applied worldwide. [ 2 ] However, sprinkler irrigation also plays an important role on irrigation‐based erosion. [ 3,4 ]…”