Multi-scale simulation of droplet-droplet interactions and coalescence

Abstract

In this work, droplet-droplet interaction is modelled using a multiphase flow computational fluid dynamics approach coupled with a reduced order surface thin-film model. An existing multiphase flow model based on a multiple marker volume of fluid method is extended to include the thin-film model that is derived to simulate film drainage on the sub-grid scale. This allows for the prediction of coalescence or rebound of colliding droplets from first principles. The model is implemented into the open source tool set OpenFOAM(supR) and tested against experimental results of colliding hydrocarbon droplets in the literature. It is found to produce accurate interface deformation results for the duration of the collision, and to consistenly predict the outcome of the collision.