Deicing behavior and residue characteristic on cold surface excited by ultrasonic vibration

An experimental study concerning the removal of iced droplets from cold flat surface by ultrasonic vibration was conducted. The detailed dynamic behavior of iced droplets located on different position of the cold surface subjected to 20 kHz ultrasonic vibration was observed. The ultrasonic vibration results in a ring-shape uneven equivalent stress distribution, which led to different residual characteristics of the iced droplets in different zones. It is found that the iced droplets can be instantly released after the ultrasonic excitation and four different residue states were observed as well as the de-icing effective and failure zones were divided. The ice residual characteristics are related to uneven distribution of equivalent stress and independent of the distance to the vibration source. The effects of freezing time and freezing temperature on residual states and residual coverage ratio of ice crystals were analyzed. The iced droplets in shorter freezing time and higher temperature can be more easily removed by the same ultrasonic input power. The outcomes of this study on the classification of ice residual types by the different ultrasonic strength zones not only can bring insights into the ultrasonic deicing theory improvement but also provides ideas for designing ultrasonic deicing devices.