Shedding of water droplets by the dual synthetic jet

Abstract

Taking into account the benefits of the dual synthetic jet (DSJ) actuator's simple form, the absence of an air supply, and powerful jet momentum, as well as the low water adhesion force of the superhydrophobic surfaces, it is possible to make droplet shedding happen easily by combining these two methods. This paper studied the motion of water droplets under the action of the DSJ actuator with inclined outlets on three different kinds of surfaces with different wettability, namely, aluminum (hydrophilic), fluorinated silicon (hydrophobic), and superhydrophobic surfaces. Particle image velocimetry measurements were used to describe the flow field of the DSJ actuator. Then, high-speed photography was adopted to compare the critical air velocity for stable motion of the droplet on the three kinds of surfaces. The droplet mobility at three different surfaces when the jet velocity was the same was compared. The displacement and changes of the contact line of water droplets with different volumes on the superhydrophobic surface under the influence of jets were studied. Besides, choosing a typical case, the effect of the dual synthetic jet on the droplet was quantitatively examined, as well as the aerodynamic drag and lift forces. And some of the phenomenon observed in the experiment was explained using the simulation data. It is hoped that this research would lead to the development of a new method of facilitating droplet transport in applications such as anti-icing, drug delivery, self-cleaning surfaces, etc.