Spray droplet velocity and energy in intermittent flow from hydraulic nozzles

Intermittent operation of a hydraulic atomization nozzle has been investigated as a potential method for flow control without distortion of droplet size spectra. This study investigated the effects of intermittent flow on the droplet velocity and energy within spray clouds from flat-fan nozzles. Spray cloud specific energy and kinetic energy median diameter, an energy analogue to the volume median diameter were developed as indicators of agricultural spray cloud behaviour. Droplet velocity and energy were slightly reduced and kinetic energy median diameter increased as intermittency increased. A doubly asymptotic, exponential function accurately described the relationship between droplet velocity and size in intermittent sprays from stationary nozzles. Simple adaptation of a continuous spray model to intermittent spray clouds did not result in accurate prediction of spray droplet velocities.