Dynamic characteristics of droplet eccentrically impacting on the surface of a hydrophilic cylinder

Droplet impact widely exists in a variety of industrial application, and its dynamic characteristics have a significant effect on the system efficiency. In this study, the behavior characteristics of droplets impacting hydrophilic wires are carried out by combining experiments and numerical simulations. Ignore the airflow disturbance in the environment, the effects of eccentricity, Weber number and Reynolds number on droplet morphology evolution under the condition of fixed size ratio of droplet/cylinder are analyzed, and the flow characteristics of central and eccentric impact of droplets are compared. The results show that the eccentricity, the Weber number and the Reynolds number of the droplets have significant effects on the dynamic characteristics of the droplets. With the increase of the eccentricity, the maximum spreading coefficient gradually increases, and there are four typical modes: symmetrical spreading-wrapping, asymmetric spreading-wrapping, unilateral wetting and partial wetting. When the Weber number is 51, the droplet spreading and retracting behavior is obvious. With the increase of Weber number, the droplet impact spreading velocity is accelerated, and the maximum spreading coefficient is gradually increased. With the increase of the eccentricity or the decrease of the Reynolds number, the instability of the spreading of the liquid film increases, and the droplet is more difficult to be caught by the wire.