ERI: Dynamics and Rupture of Liquid Bridges Between Particles Under Extension, Shear, and Vibration via Lattice Boltzmann Simulations

A “liquid bridge” is a small body of liquid connecting two solid surfaces that maintains its shape due to surface tension. When liquid bridges connect solid particles, they cause the particles to adhere to each other. For example, sand castles owe their stability to water bridges that connect sand particles. Liquid bridges can also cause plugging of oil pipelines by forcing aggregation of gas hydrate particles. This project will use numerical simulations to examine the dynamics of liquid bridges between particles. The fluid dynamics of the bridges will be analyzed when the particles are moved apart or oscillated. Results from the project will help improve predictions of the behavior of wet particulate materials. The project will also support training of students in advanced methods of numerical simulation. This project will investigate the dynamics of liquid bridges between particles using Lattice Boltzmann Method (LBM) numerical simulations. The LBM is a computational fluid dynamics (CFD) technique that is well-suited to multiphase flows with complex geometry. In many engineering situations, liquid bridges can form between freely-moving solid particles. These bridges can rupture due to particle motion or can force multiple particles to aggregate into macroscopic structures. Previous simulations intended for static or quasistatic situations cannot capture these dynamic processes. This project will customize LBM simulations to elucidate the rupture of liquid bridges undergoing extensional, shearing, or vibrational deformations. The simulations will capture the two-way coupling between particles and fluid, the effects of inertia and viscosity, the effects of particle shape, and the effects of contact line pinning, e.g. due to surface roughness or faceted particles. The predictive capability developed by this project will benefit multiple applications, especially plugging of oil pipelines due to hydrate particles held together by liquid bridges. However, other applications involving liquid bridges, e.g. the mechanics of wet soils, gravure printing, or 3D-printing of particulate materials will also benefit. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.