Rebound dynamics of two droplets simultaneously impacting a flat
In this letter, we investigate the rebound dynamics of two equally sized
droplets simultaneously impacting a superhydrophobic surface via lattice
Boltzmann method (LBM) simulations. We discover three rebound regimes
depending on the droplet distance: a complete-coalescence-rebound (CCR)
regime, a partial-coalescence-rebound (PCR) regime, and a
no-coalescence-rebound (NCR) regime. We demonstrate that the rebound
regime is closely associated with dynamic behaviors of the formed liquid
ridge or bridge between two droplets. We also present the contact time
in the three regimes. Intriguingly, although partial coalescence takes
places, the contact time is still dramatically shortened in the PCR
regime, which is even smaller than that of a single droplet impact.
These findings provide new insights into the contact time of multiple
droplets impact, and thereby offering useful guidance for some
application such as anti-icing, self-cleaning, and so forth.