Spray boom motions and spray distribution .2. Experimental validation of the mathematical relation and simulation results

Experimental work is reported, which was carried out on a patternator, to verify the semi-empirical algorithm developed in part one of the paper. Four experiments were performed. In each experiment, a different nozzle was moved across the patternator at an arbitrary velocity. Simulated spray deposition patterns of the nozzles were compared with the captured spray liquid in the measuring jugs of the patternator. Relative deviations between measured and calculated spray deposit distributions were always less than 7%. The effect of boom movements, on the spray deposition pattern simulated by the algorith, is discussed. A measured three dimensional static spray model is used in the algorithm to generate the spray deposition at the tip of a moving spray boom. From these simulations, it is concluded that both rolling motions and horizontal vibrations of the boom can severely disturb the spray deposition pattern. Simulations showed that local under and over applications caused by boom rolling, vary between zero and 10 times the desired dose. Horizontal boom vibrations cause variations between 0.3 and four times the prescribed dose. (C) 1997 Silsoe Research Institute.