Droplets formation and diffusion simulation and test of microporous atomizer for robotic immunization spraying

To meet the precision spraying of poultry house immunization robots, an immunization sprayer based on microporous atomization is designed to ensure uniform and efficient atomization of immunological reagents. The optimal driving frequency is determined through modal analysis of the piezoelectric atomization plate, which is 113 kHz. Using the resonant frequency-driven droplet generation model, the simulation of single-pore droplet formation is realized, and the initial droplet velocity and diameter are extracted as boundary conditions for input into the droplet diffusion model. This reveals the diffusion and evolution rules of the atomization field, along with the distribution characteristics of velocity and particle size. The atomization diffusion distance in a dynamically stable state is 68.36 cm, with a diffusion range of 32°. Within 15-55 cm from the atomizer, over 90% of droplets have an adequate particle size of 30-200 μm. Practical testing with the VisiSize P15 droplet size measuring instrument showed that the diffusion angle of the stable atomization morphology is approximately 30°, with a diffusion distance of 65 cm. The simulation results show an absolute relative error of less than 7%, while the droplet size distribution has an absolute relative error of less than 10%. For the segmented characteristics of droplet velocity attenuation, the absolute relative error is less than 18%, with an absolute error of less than 0.15 m/s. These results demonstrate that the overall atomization and diffusion effect meet the requirements for immunization spraying.