Droplet Impact and Coalescence

In CACT we have developed 3D numerical models, using a Volume-of-Fluid (VOF) method, to simulate droplet impact and coalescence on a surface. The model is used to simulate the formation of coatings by droplets sprayed on a substrate. Predictions from the model have been validated by comparing them with photographs of overlapping droplets landing on a surface. The model is also useful for studying the entrapment of air bubbles under droplets, which is important in understanding how these bubbles are formed in spray coatings.

1
2
3
4

Simulation of landing one droplet on another one and their coalescence

Coalescence2

(Left) Simulation and (right) images of bubble entrapment between two impacting droplets at the interface