Numerical Studies on Rupture and Forces in Liquid Bridges Undergoing Extension Between Spherical Particles Using the Lattice Boltzmann Method

When a volume of liquid is introduced between two solid particles, a capillary bridge will be formed. The extension of liquid bridges between spherical paricles has been widely investigated, where the critical separation distance that leads to rupture, and the forces exerted on the particles, have been of interest to researchers. Most of the previous research has concentrated on static or quasi-static scenarios, but fully dynamic situations, commonly encountered in practical applications, are not yet fully understood. For this purpose, we have developed predictive numerical simulations using the Lattice Boltzmann Method (LBM), where they account for the dynamic influence of viscous forces and inertia, which are not present in static scenarios. We have performed three different validation studies which examine different aspects of the problem. 1. The critical separation distance of a static bridge, beyond which rupture occurs; 2. the combined capillary and pressure forces on a particle for a quasi-static separation; 3. the combined capillary, pressure, and viscous forces on a particle for a dynamic separation/approach. All results were compared to theoretical expressions or experimental studies, and have shown relatively small errors, rendering the numerical simulations sufficiently accurate for such a complex situation. Once the code has been validated in terms of its ability to predict rupture and the various forces exerted on particles, it is planned to analyze novel dynamic scenarios, which are more representative of real-world applications. Specifically, rupture dynamics will be compared in two situations where the particles are moving with either a constant applied force or a constant velocity. This will involve analyzing the critical separation distance, which is anticipated to be different in this comparison.