Experiment of droplet impact on wetted surface

The behavior of droplet impacting onto dry solid surface and wetted surface has great influence on separating efficiency of the steam separator in steam and power system. Firstly, a review and comparison of published experimental results pertaining to splashing thresholds and mechanisms is summarized, mainly varying the surface condition: increasing the dimensionless surface roughness Rnd on dry solid surfaces or the dimensionless film H* on wetted surfaces gradually. Then impact of droplets with different velocity on wetted surfaces with three kinds of impact angles was studied experimentally using a high-speed camera at 11,000 fps. Experiments were performed at normal pressure and temperature. The impacting outcomes of deposition, crown without splashing, splashing are displayed and discussed. Finally, the thresholds between non-splashing and splashing regions are studied quantitatively. (author)