Modeling the dynamics of partially wetting droplets on fibers

We simulate gravity driven dynamics of partially wetting droplets moving along a fibre using the lattice Boltzmann method. For the so-called clamshell morphology, we find three possible dynamic regimes upon varying the droplet Bond number and the fibre radius: compact droplet, droplet breakup and droplet oscillation. For small Bond numbers, in the compact droplet regime, the droplet reaches a steady state and its velocity scales linearly with the driving body force. A similar scaling law can also be observed for the barrel morphology. For higher Bond numbers, in the droplet breakup regime, satellite droplets are formed trailing the initial moving droplet. We f ind such droplet satellite formation is easier with increasing fibre curvature (smaller fibre radius). Finally, in the droplet oscillation regime, favoured in the mid-range of fibre radius, the droplet shape periodically extends and contracts along the fibre.