The 239th R-CCS Cafe - part 3

Wettability is the ability of a liquid to spread over a solid surface and plays a central role in a wide range of engineering applications, such as self-cleaning, anti-fouling, anti-icing, drag reduction, and so on. It is governed not only by the chemical composition but also by the roughness or microstructure of surfaces. Therefore, significant efforts have been devoted to relating the geometrical characteristics of the surface microstructure to the wettability to achieve desired properties. However, major issues still remain unresolved, including the origin of the contact-angle hysteresis and the transition from the Cassie-Baxter state to the Wenzel state. To address these issues, we have developed a numerical method for simulating liquid-gas two-phase flows in complex geometries and have conducted some preliminary analyses of the behavior of liquids inside and outside patterned surfaces.
In this presentation, we will first discuss the numerical methods used in the present study, along with issues to be addressed in the future. Then, we will show recent results concerning the capillary flow inside rectangular open microchannels.