Numerical Study on Liquid Bridge Morphology and Capillary Force between Two Angled Cylindrical Particles

Wet particulate systems are ubiquitous in industrial processes, where their macroscopic behaviors are significantly influenced by liquid bridges formed between particles. This study investigates static liquid bridges between two cylindrical particles using an experimentally validated Surface Evolver simulation. A systematic analysis was conducted on the morphological evolution and capillary forces of liquid bridges in both parallel and nonparallel configurations, with particular focus on the effects of contact angle, liquid volume and relative orientation between cylinders. The results demonstrate that increasing contact angle facilitates a transition in the liquid bridge profile from concave to convex, accompanied by a shift in the capillary force from attractive to repulsive. An increase in liquid volume enhances the stability of hydrophilic liquid bridges but promotes instability in hydrophobic ones. As the cylinder configuration transitions from parallel to perpendicular, both the liquid bridge symmetry and the resultant capillary force decrease, despite nearly constant gas–liquid and liquid–solid interfacial areas. Further analysis revealed strong positive linear correlations between the capillary bridge force and both the axial wetting length and liquid–solid interfacial area. This work provides a theoretical basis for predicting and controlling liquid bridge behavior in wet cylindrical particle systems.