Numerical analysis for the optimum condition of ultrasonic nebulizing

To obtain the optimal driving conditions for ultrasonic nebulizing, the capillary wave caused by ultrasound on the water surface was analyzed theoretically. From the possible solutions of Mathieu's equation, the condition for amplitude diverging with time changes was investigated. The possible ranges of the driving frequency and the vibration displacement for nebulizing were obtained numerically, and the droplet size distribution was obtained in these ranges. The results of this study could be applied to design the desirable ultrasonic nebulizer.