Phase-field model-based simulation of two-phase fluid motion on partially wetted and textured solid surface

The applicability of a numerical method is preliminarily examined to determine its suitability for simulations of microscopic immiscible liquid-liquid motion on solid walls, which is used for evaluating fluidic devices with heterogeneously wettable and textured surfaces. The method adopts a conservation-modified Allen-Cahn equation for calculations of diffuse-interface advection and formation based on a phase-field model, and a lattice-Boltzmann method is employed as numerical scheme for solving the two-phase fluid-dynamics equations. The simulations demonstrate the ability of the method to successfully capture the shape and motion of a droplet, not only on flat and grooved surfaces in a stagnant liquid under an external force, but also in a liquid flow inside a rectangular microchannel.