Excitation-Induced Droplet Removal in Shearing Gas Flow

The dynamics of sessile droplets under shear gas flow are of significant interest across various applications. In this study, the behavior of droplet detachment under shear gas flow is investigated, with a focus on the oscillatory motions observed before detachment. The forces involved include drag from the shear gas flow, adhesion due to surface tension and contact line pinning, and inertial forces resulting from the droplet’s oscillation. To enhance the detachment process, the application of acoustic pressure waves was explored. Varying acoustic frequencies were applied in conjunction with shear gas flow, and an optimal frequency that minimizes the droplet’s area at detachment was identified. For example, at a shear gas velocity of 2.3 m/s, the

smallest droplet area upon detachment was observed at a frequency of 40 Hz. This suggests a resonance effect that facilitates more efficient removal. Emphasis is placed on refining the relationship between droplet characteristics, shear flow parameters, and the optimal acoustic frequency to further improve the applicability of this technique. This research highlights the potential for using acoustic pressure waves to optimize droplet detachment processes, with implications for improving efficiency in applications requiring precise liquid management.