Experimental investigation of the impact and freezing processes of a water droplet on an ice surface

In the present study, we report for the first time the detailed dynamic motions of a water droplet impacting on an ice surface. Besides, the effects of the initial height of the water droplet and the ice surface temperature on the impact and freezing processes of the water droplet were experimentally investigated. During the experiment, an ice surface was generated first and then kept at a desired temperature by a constant temperature bath circulator. After that, a deionized water droplet was deposited onto the ice surface and its impact and freezing processes were recorded. The results showed that, during the impact process of the water droplet, once the water droplet reached its maximum contact diameter, the contact line of the water droplet was pinned on the ice surface without recoiling. Besides, at the same initial height of the water droplet, the decrease of the ice surface temperature resulted in the reduction of the maximum spreading factor and an apparent increase of the height of the ice bead. Moreover, once the droplet initial height was increased, the maximum spreading factor increased while the height of the ice bead reduced significantly.