Effect of Pressure and Nozzle Shape on the Characteristics of Sprinkler Droplet Spectra

Abstract In the measurement of sprinkler droplet sizes, the assumption is often made that a change in volume mean diameter determined at one position accurately reflects a change of the overall droplet spectra. Sprinkler droplet distributions from circular and square nozzles at several pressures were measured to test this assumption. It was found that a smaller value of the largest volume mean droplet diameter, which occurs at the end of the spray stream of the sprinkler pattern, corresponds to a formation of smaller droplets over the entire droplet spectra. The assumption was therefore verified. It was also found that, for both circular and square nozzles, increasing pressure decreased drop size in overall droplet spectra, and for a given pressure, changing nozzle shape from circular to square also decreased drop size.