Numerical simulation of dynamic contact angle using a force based formulation

• Published in: Journal of non-Newtonian fluid mechanics 2011-09, Vol.166 (16), p.900-907
• Main Authors: Deganello, D., Croft, T.N., Williams, A.J., Lubansky, A.S., Gethin, D.T., Claypole, T.C.
• Format: Article
• Language: English
• Subjects: Capillary flow; Computer simulation; Condensed matter: structure, mechanical and thermal properties; Contact; Contact angle; Contact line; Correlation; Dynamic contact angle; Dynamical systems; Dynamics; Exact sciences and technology; Free surface; Level-set method; Mathematical analysis; Mathematical models; Physics; Solid-fluid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Wetting
• ISSN: 0377-0257; 1873-2631
• DOI: 10.1016/j.jnnfm.2011.04.008

► Advancing capillary flows simulated within a level-set numerical framework. ► Contact angle dynamics simulated by force applied on solid-fluids interface. ► Experimental correlation of capillary number on contact angle is reproduced by model. ► Successful simulation of Jiang’s empirical model. ► Ability to work with meshes of low resolution. A method for the numerical simulation of the dynamic response of the contact angle is presented and its development discussed. The proposed method was developed within a level-set framework by modelling forced capillary flows and it is based on the introduction of a force function to capture the balance of forces in the contact region between solid boundaries and a diffuse free-surface fluid interface. The proposed approach allows the system to define its own dynamic contact angle and its own contact line dynamics, without introducing numerical discontinuities such as locally prescribed angles or slip-length. The method was developed through numerical testing and comparisons with experimental and empirical models reported in the literature. These showed the validity of the proposed approach, which was able to reproduce the experimental correlation between the capillary number and the dynamic contact angle reported by [R.L. Hoffman, Study of advancing interface. 1. Interface shape in liquid–gas systems, J. Colloid Interf. Sci. 50 (1975) 228–241]. By using a single constitutive model for the force function, the simulation results of the dynamic contact angle showed an excellent agreement with the values predicted by Jiang’s empirical equation [T.S. Jiang, O.H. Soo-Gun, J.C. Slattery, Correlation for dynamic contact angle, J. Colloid Interf. Sci. 69 (1979) 74–77] through different material properties and flow speeds. The proposed approach also demonstrated the ability to work with meshes of low resolution.