Impact of Droplets on to Moving Liquids
Our recent work includes the first systematic study on the impact of droplets onto moving pools of liquids. The findings are of broad interest because they bring new and strong evidence that the splashing behavior is only regulated by two dimensionless groups that embed all the important physical variables, namely, viscosity, surface tension, density and relative speed of impact. Our experimental setup and novel imaging techniques have allowed us to identify previously unknown phenomena including conditions where droplets can remain permanently ‘surfing’ a liquid surface or where droplets violently splash and break up into several smaller drops. This fundamental study is potentially of great importance in many fields of technology and nature, as our parametric conditions covers all scenarios in which droplets can be formed, including those of inkjet printing, spraying and other liquid dispensing techniques. Our study provides the experimental data to validate numerical and theoretical models for this important process.
These results were presented in the Journal of Fluid Mechanics 809 716 (2016).