Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : April 22, 2024 - April 23, 2024
Wettability is one of the important surface properties in various industrial systems. The wettability on the surface is usually evaluated by an equilibrium contact angle, although it is insufficient to evaluate the droplet removability on solid surfaces. This study focuses on the dynamic characteristics of the contact line to clarify the dynamic behavior of droplets on a solid surface. In our previous study, the dynamic wetting and dewetting of a water droplet on a hydrophobic solid surface with an equilibrium contact angle of approximately 100o was investigated both experimentally and theoretically. We proposed a theoretical model of the extension–contraction experiment and numerically calculated the radius of the contact line circle of a liquid droplet, contact line velocity, and dynamic contact angle. The calculation results were in quantitative agreement with our previous experimental results, indicating that our constructed model was appropriate. However, its theoretical model was constructed based on the approximation that the equilibrium contact angle is nearly equal to 90°, which makes it difficult to apply on many surfaces. Therefore, in this study, we numerically solved the differential equation of the radius of the contact line circle with no approximation regarding the equilibrium contact angle and discussed the effects of the equilibrium contact angle on the contact line radius.
