Kinetic Energy, Evaporation and Wind Drift of Droplets from Low Pressure Irrigation Nozzles

A simulation model was developed to estimate kinetic energy, evaporation and wind drift of droplets from low pressure irrigation sprinklers. The model was partially verified using data from literature. Droplet size, height, size, flow rate and deflection plate angle of the nozzle and air temperature, wind direction and velocity and air humidity were changed to determine the influence on evaporation and travel of the droplet. To approximate representation of the complete nozzle, droplet sizes were weighted according to percentage volume data. Two nozzles, one representing low pressure and the other high pressure were simulated. Evaporation decreases rapidly when droplet diameter is decreased from 0.3 mm to 1 mm. The influence of air temperature is more evident at small droplet size. Evaporation estimates for different wind velocities and nozzle elevations indicate high dependence on these parameters. The kinetic energy of droplets at lower elevations with deflection plate angles either horizontal or upward (10 degrees) was relatively low. Small droplet wind drift at higher wind speeds and nozzle elevations was large.