Effect of Trajectory Angle on Performance of Sprinklers in Wind

Abstract

The effect of changing the trajectory angle of a medium‐sized irrigation sprinkler operating in windy conditions has been studied using a computersimulation model. The model, which has been verified both in still air and under windy conditions, shows that the trajectory angle that maximizes distance of throw is a function of the wind velocity and varies from 29° in still air to less than 5° in winds greater than 8 m/s. The advantage gained from trajectory angles greater than 25° in still air is quickly overcome by the disadvantages in range reduction and drift in relatively light winds. When choosing the appropriate trajectory angle, consideration should be given to the drop‐size distribution and the wind velocity, because wind drift and range both depend upon drop size and trajectory angle.