Visual Study of the Impact and Freezing Process of a Water Droplet on Carbon Fiber Plates

The present study investigates the effects of droplet impact height, tilt angle, and surface temperature on the impact and freezing process of water droplet on a cold surface by using a Motionpro high-speed camera and a DSA-30 droplet surface analyzer. The temperature of the plate was changed from an ambient temperature of 24.0°C to C, while three impact heights ( = 100, 150 and 200 mm) were set. The data indicated that increasing impact height led to increase in the maximum spreading diameter and maximum endpoint displacement, but its effect on droplet spreading time was not significant. With decreasing the surface temperature, the rate of change in the droplet diameter was smoother and the droplet freezing time reduced. Moreover, at low Weber number ( ), the impact height has less effect on the freezing time of the droplet. Besides, compared with the horizontal plate, the droplet freezing time on plate tilted at 30° was higher for the same impact height.