Experimental investigation on the movement of triple-phase contact line during a droplet impacting on horizontal and inclined surface

• Published in: Chemical engineering science 2020-11, Vol.226, p.115864, Article 115864
• Main Authors: Chen, Mingjing, Wu, Dan, Chen, Deqi, Deng, Jian, Liu, Hanzhou, Jiang, Junze
• Format: Article
• Language: English
• Subjects: Contact angle; Contact line; Droplet; Experiment; Wettability
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2020.115864

•Dynamic wetting behavior during droplet impacting is experimentally studied.•The effects of size and surface on the dynamic wetting process are presented.•Process of droplet impacting and contact line movement can be described by combined model. The dynamic wetting process of a droplet impacting on a wall is a fascinating phenomenon relative to industrial application such as chemical engineering. However, the wetting detail, especially the characteristics of movement of the triple-phase contact line (TPCL) during impacting is not clear. In this paper, the dynamic behavior of the droplet during impacting was recorded by a high-speed camera, and the dynamic contact angle (DCA) of the droplet and the transient change of the velocity of the TPCL are mainly concerned. This paper will discuss the effects of droplet size, surface wettability, surface microstructure and the inclination angle of the plate on the TPCL movement, separately. Finally, a combined model of the transient force of the droplet on the inclined surface is proposed and verified by experimental data.