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.


Simulation of landing one droplet on another one and their coalescence


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