Interface-resolved simulations of normal collisions of spheres on a wet surface

Detailed knowledge of micro-mechanics of individual particle collisions in the presence of liquid is crucial for modelling/understanding of wet granular flows that are omnipresent in nature and industrial applications. Despite many reported studies, very limited detailed interface-resolved modelling of such collision problems has been conducted. This paper presents an improved model for direct numerical simulations of normal impacts of spheres on wet surfaces. This model combines the immersed boundary method and the volume-of-fluid method supplemented with a model describing gas-liquid-solid contact line. It is demonstrated that our model not only correctly describes the collision dynamics of wet particles, but also well captures the dynamics of the liquid bridge formed during the collision. Quantitative agreement is obtained between the simulation results and the experimental data. It is concluded that the developed model constitutes a powerful tool to complement experimental studies, which are challenging for more complex wet collision systems in practice