title: Curvature estimation from a volume-of-fluid indicator function for the simulation of surface tension and wetting with a free-surface lattice Boltzmann method.
abstract: The free surface lattice Boltzmann method (FSLBM) is a combination of the hydrodynamic lattice Boltzmann method with a volume-of-fluid (VOF) interface capturing technique for the simulation of incompressible free surface flows. Capillary effects are modeled by extracting the curvature of the interface from the VOF indicator function and imposing a pressure jump at the free boundary. However, obtaining accurate curvature estimates from a VOF description can introduce significant errors. This article reports numerical results for three different surface tension models in standard test cases and compares the according errors in the velocity field (spurious currents). Furthermore, the FSLBM is shown to be suited to simulate wetting effects at solid boundaries. To this end, a new method is developed to represent wetting boundary conditions in a least-squares curvature reconstruction technique. The main limitations of the current FSLBM are analyzed and are found to be caused by its simplified advection scheme. Possible improvements are suggested.
authors.affiliation: Lehrstuhl für Systemsimulation, Universität Erlangen-Nürnberg, Cauerstraße 11, 91054 Erlangen, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Bogner
authors.affiliation: Lehrstuhl für Systemsimulation, Universität Erlangen-Nürnberg, Cauerstraße 11, 91054 Erlangen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rüde
authors.affiliation: Forschungszentrum Jülich, Helmholtz-Institut Erlangen-Nürnberg (IEK-11), Fürther Straße 248, 90429 Nürnberg, Germany and Department of Applied Physics, Technische Universiteit Eindhoven, P. O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: Jens
authors.initials: J
authors.lastname: Harting