Freezing modes of water droplet on cold plate surface under forced convection

The water droplet freezing modes on the cold plate surface under forced convection are experimentally studied. The formation mechanism of the peak freezing mode is analyzed. A new peakless freezing mode is found. The results indicate that the stronger convective heat transfer on the windward of the droplet causes the solid-liquid interface of the freezing droplet to incline windward. In the peakless mode, the droplet freezing is driven by frosting around the solid-liquid interface. A peakless solidification slope is formed by the liquid penetrating the frost layer. The increase of the airflow velocity can transform the freezing mode from the peak mode to the peakless mode, promoting ice nucleation on the droplet and postponing droplet solidification. The critical criterion for freezing mode transition is obtained.