DEVELOPMENT AND CHARACTERIZATION OF A FIX ED SPRINKLER WITH A ROTATING SERRATED PLATE

The objective of the present work was to develop serrated deflector pl ates with rotating movement and to determine the precipitation profile and hydraulics characteristics of one irrigation spray nozzles workin g with the deflector plates developed. The number of serrates and the diameter used were the same as for the conventional fixed plate. Howev er, serrates were made in helicoydal form to ensure the rotating movem ent. Plane, concave and convex plates with a ten-degree angle were dev eloped. The concave plate presented the highest wetted radius and cons equently the lowest average precipitation rate, specially for lower he ight of sprinkler positioning. In general, the average precipitation r ate decreased as the sprinkler height increased. The precipitation pro files for sprays with the plate were used to simulate the Christiansen Uniformity Coefficient (CUC) for center pivot and linear systems. The CUC increased as the sprinkler spacing decreased. All the CUC were hi gher than the minimum recommended. There was no difference between the CUC values for the different plates.