Simulating Sprinkler Performance in Wind

Abstract

The uniformity of irrigation systems is important to efficiency, yield, and economics. Wind strongly affects this uniformity. A method is presented for simulating the operation of a sprinkler system in wind. Equations describing the motion of airborne water droplets are shown. The trajectories of water droplets ejected from a sprinkler were numerically computed. Composite results led to predictions of application patterns. Sprinkler droplet size distribution was used to predict the pattern around a sprinkler, and patterns were superimposed to represent a set (not continuously moving) system. Coefficients of uniformity were then computed. The model was validated by comparing predictions with observed application patterns. Individual and multiple sprinkler tests were compared. The simulation system appeared to be an effective predictor of sprinkler performance in wind. Use of this type model can lead to improved sprinkler designs, although variability of the wind vector affects the accuracy of prediction.