The Influence of the Scatterer Design and Nozzle Diameter on the Radial Rain Distribution of a Sprinkler Nozzle

Improving sprinkler devices for wide-span irrigation machines requires investigating the influence of their design parameters on the characteristics of the artificial rainfall they produce. The aim of this study was to evaluate the effects of deflector design and nozzle diameter on the radial distribution of rainfall intensity. Experimental investigations were conducted using a sprinkler nozzle equipped with interchangeable orifices of 3, 4, and 5 mm in diameter and two deflector configurations designed to produce large- and medium-sized droplets. The experiments were performed at a constant operating pressure of 1.4 MPa. Water distribution was measured along three radial lines using rain gauges positioned at 0.5 m intervals. Rainfall intensity values averaged across the three radial lines were used for comparative analysis. The results showed that deflector design and nozzle diameter affected both the magnitude and radial position of maximum rainfall intensity. With a 3 mm nozzle diameter, the maximum intensity was 0.295 mm/min for the large-droplet deflector and 0.346 mm/min for the medium-droplet deflector. At nozzle diameters of 4 and 5 mm, higher maximum intensities were observed for the large-droplet deflector, reaching 0.314 and 0.408 mm/min, respectively. Increasing the nozzle diameter from 3 to 5 mm shifted the radial position of maximum intensity from 1.5 to 4.0 m for the large-droplet deflector and from 1.5 to 3.5 m for the medium-droplet deflector. These findings demonstrate the importance of considering deflector design and nozzle diameter together when improving sprinkler devices for wide-span irrigation machines.