Simulated and Measured Coefficients of Variation for the Spray Distribution under a Static Spray Boom

The spray pattern characteristics of a number of different series of flat fan nozzles were investigated in two ways. The first method was to measure the distribution by means of a classic patternator with collecting cylinders. The second method consisted of numerical simulation of the distribution, by combining the real distributions of a number of nozzles. The real distribution was measured on a classic patternator for each nozzle separately. The numerical simulation is computerized and automated. This system allows both time and labour gains, and permits multiple trials with the same series of nozzles. Numerical simulation results are compared with spray distributions obtained on the patternator. The sprayed volumes of liquid were found to be significantly different from the simulated ones (level of significance 95%). However, the coefficient of variation characterizing the homogeneity of the spread volumes can be calculated using simulated volumes. This can be done once an empirical linear relation is established between the coefficients of variation obtained from simulated volumes and the ones obtained from measured volumes.