Dynamics of viscous coalescing droplets in a saturated vapor phase

TL;DR

This study uses Lattice Boltzmann simulations to explore how saturated vapor influences the coalescence dynamics of viscous liquid droplets, revealing faster initial bridge formation due to vapor condensation effects.

Contribution

It provides new insights into the role of vapor phase and condensation in droplet coalescence dynamics, which was not thoroughly understood before.

Findings

Earlier onset of coalescence in saturated vapor

Faster initial growth of the liquid bridge in saturated vapor

Vapor transport through condensation accelerates coalescence

Abstract

The dynamics of two liquid droplets coalescing in their saturated vapor phase are investigated by Lattice Boltzmann numerical simulations. Attention is paid to the effect of the vapor phase on the formation and growth dynamics of the liquid bridge in the viscous regime. We observe that the onset of the coalescence occurs earlier and the expansion of the bridge initially proceeds faster when the coalescence takes place in a saturated vapor compared to the coalescence in a non-condensable gas. We argue that the initially faster evolution of the coalescence in the saturated vapor is caused by the vapor transport through condensation during the early stages of the coalescence.