A Phenomenon Study on Spreading and Evaporating Process of Droplet on DBD Actuator for Wind Turbine Anti-icing

Abstract

This paper reports on the phenomenon of the unique spreading and evaporation process of water droplets on the surface of a dielectric barrier discharge (DBD) actuator. High-speed photography was used to capture the droplet spreading dynamics, and the temperature field evolution was characterized by infrared imaging. On the DBD actuator, the maximum spreading diameters of the droplets are shown to be increased by ∼95%, and the contact angles decrease from 58º to 13º, indicating that the DBD plasma significantly increases the hydrophilicity of the actuator surfaces. It is also revealed that the evaporation time induced by the DBD plasma is 6.54 times faster than that of an electric heater. It is argued that coupled effects of the hydrophilicity caused by plasma and the heat flux in the streamers bridging the electrodes and the droplets should be the crucial points of plasma evaporation physics of impinging water droplets, which are especially meaningful in anti-icing applications.