Establishment of a static nozzle atomization model for forest barrier treatment

Currently, the theory of using automatic target spray technology for forest barrier treatment in China has some shortcomings. Therefore, this study established an atomization model for two common brands of nozzles (Lechler and Feizhuo) used in this field. This model includes the two most important parameters: droplet size and spray axis velocity. A specific model for the two brands of nozzle was obtained. The obtained droplet size calculation model was validated with actual tools, which showed that at six different pressures, the average absolute error of the theoretical data for the droplet size obtained from the selected Lechler nozzles was 6.92 μm compared with the actual measured data, whereas the average relative error was 3.07%. The absolute and average relative errors for the Feizhuo nozzles were 11.41 μm and 4.43%, respectively. The model had a high degree of confidence. The test also verified that the droplet sizes at different distances from the same nozzle did not vary dramatically at a given pressure in the close-up range (30-50 cm). In addition, the droplet sizes at different angles did not significantly vary at given pressures and flow rates. However, droplet sizes that had the same angle increased as the flow increased. The classical theoretical model of spray axis velocity in connection to this study also improved, and the test results were verified by the computational fluid dynamic simulation method. Compared with the simulation data, the average absolute error of the improved theoretical data for the Lechler nozzle was 0.64 m/s for the selected nozzles, and the average relative error was 6.42%. The absolute and average relative errors for the Feizhuo nozzle were 0.67 m/s and 6.00%, respectively.