In-flight digital image analysis of sprinkler drops

摘要

Abstract: anding the process of sprinkler droplet formation and behavior while in flight is crucial to the improvement of water and chemical application by sprinkler irrigation. A relatively simple and inexpensive method is presented which allows in-flight characterization of irregularly shaped liquid droplets and ligaments produced by irrigation sprinkler devices. A high-speed photographic image acquisition probe was constructed to allow nonintrusive, direct investigation of water jet breakup, drop formation and behavior, size, and shape of monodispersed drops at various locations from the nozzle. Image contrast and motion freezing was accomplished by backlighting the liquid particles with a 1.5 $mu@s duration stroboscope. High resolution film allowed analysis over a wide range of particle sizes (0.3 mm to 50 mm). Image processing and analysis was performed on digitized images using commercially available software. This software provided geometrical size and shape parameters of the breakup fragments and allowed discrimination between in and out-of-focus drops by post analysis. Applications of the method included: studying the effect of wind direction and speed, nozzle type, and pressure on sprinkler jet breakup. !22