Lattice Boltzmann simulations of contact line motion in a liquid-gas system

TL;DR

This paper employs lattice Boltzmann simulations to study the steady-state interface profile and contact line motion of a droplet in a liquid-gas system under shear, revealing the influence of capillary number and dynamic contact angle.

Contribution

It introduces a lattice Boltzmann method with partial wetting to analyze contact line dynamics and confirms the dependence of interface profiles on capillary number.

Findings

Interface profiles depend on capillary number

Dynamic contact angle emerges at zero interfacial curvature

Finite size effects influence contact line behavior

Abstract

We use a lattice Boltzmann algorithm for liquid-gas coexistence to investigate the steady state interface profile of a droplet held between two shearing walls. The algorithm solves the hydrodynamic equations of motion for the system. Partial wetting at the walls is implemented to agree with Cahn theory. This allows us to investigate the processes which lead to the motion of the three-phase contact line. We confirm that the profiles are a function of the capillary number and a finite size analysis shows the emergence of a dynamic contact angle, which can be defined in a region where the interfacial curvature tends to zero.