Droplet Detachment during Condensation Process on a Downward-facing Grooved Surface

orc2019 Tracking Number 215

A hybrid thermal lattice Boltzmann method is employed to numerically simulate the condensation process on a two-dimensional downward-facing grooved surface. Nucleation, growth, coalescence and detachment process on surfaces with different wettability are reproduced with a focus on the droplet dynamic behavior during the detachment. The droplet detachment during condensation in pendent state is investigated in a wide range of equilibrium contact angle. The numerical simulation identified a single-droplet mode and a coalescence-induced mode for droplet detachment during condensation process on the downward-facing grooved surface. In the single-droplet detachment mode, the critical departure radius is negatively correlated with the equilibrium contact angle with two inflection points. The first inflection point is related to the transition of droplet wetting morphology from Wenzel to Cassie mode, and the second is corresponding to the transition of departure morphology from breakup to non-breakup mode.