Numerical simulation and experiment for the ultrasonic field characteristics of ultrasonic standing wave atomization

Ultrasonic standing wave atomization (USWA) can obtain micron-sized spherical droplets from high viscosity or high surface energy liquids, which mainly depend on the high-energy density of a sound field. In this paper, the formation of an ultrasonic field can be generated by the vibration of a tool head driven by magnetostrictive transmitters. Based on the simulation environment of Comsol Multiphysics software, the numerical study about the characteristics of ultrasonic standing wave sound field was carried out. The influence of the arrangement of transducer, the shape and parameters of transducer tool head, the length of resonator and the pressure of environment on the sound pressure was studied. Then, the influence of ultrasonic frequency on the ultrasonic standing wave sound field was studied. It could be seen that the sound pressure distribution is better when the double transmitters were facing each other, the length of the cavity was with n = 5 sound pressure nodes, and the tool head was spherical. On this basis, the influence of primary frequency (f = 20 kHz) on the sound pressure was analyzed, and the optimal ultrasonic frequency f = 19.8 kHz was obtained. The sound pressure of the ultrasonic standing wave field was measured, and the computed results were compared with the experimental results. Finally, based on the optimized parameters of the simulation, USWA was used to atomize glycerol-water solution with different concentrations. The experimental results showed that the ultrasonic standing wave field established can atomize glycerol aqueous solutions with viscosities from 1.01 × 10–3 Pa·s to 1200.58 × 10–3 Pa·s.