On the Accuracy of Modeling the Wetting Angle Using Different Schemes in the Lattice Boltzmann Method

This paper investigates the accuracy of modeling wetting angle in combination with two numerical schemes describing interfacial tension in the lattice Boltzmann method. Both schemes are based on the color-gradient method. In the first, interfacial tension is modeled using the perturbation operator. The second scheme is based on a direct calculation of the mass force creating interfacial tension and the interface curvature. The accuracy of modeling the wetting angle is assessed by solving two problems about a fixed (Laplace test) and moving (Washburn equation) meniscus in a flat capillary. The results show a significant advantage in numerical accuracy of the second scheme compared to the first one. The first scheme is valid only in cases of low interfacial tensions and wetting conditions close to neutral.