A two-directional calculation model for the combination uniformity coefficient of an impact sprinkler

Abstract

An impact sprinkler loaded on a remote control trailer can be used for motion to improve the efficiency of a single Hard Hose Traveler in small and medium-sized irregular fields. Herein, a model for calculating the combination uniformity coefficient (CU) was established in the square test area under two-directional motion. The accuracy of the irrigation uniformity model was verified using the test data of application depth ( hn). The results revealed that the nozzle diameter, speed of sprinkler motion ( v), and motion methods can significantly impact the average application depth ([Formula: see text]) and the CU value of sprinkler irrigation performance. The motion methods included uniform motion and a constant speed combination motion. The highest CU values were recorded when the primary and secondary nozzle diameters were 10.5 and 4.5 mm, respectively (overall value, about 81.7%). The CU value gradually decreased with the increasing v value of the sprinkler. The CU value was higher under the constant speed combination motion than the uniform motion. The [Formula: see text] value gradually decreased with increasing v value. The [Formula: see text] value was classified based on the water requirement of different crops. The optimal CU value corresponding to each grade of the [Formula: see text] value was obtained in different schemes of the combination of sprinkler speeds. This research guides the realization of variable spraying of a Hard Hose Traveler and the intelligent uniform motion of the sprinklers.