Low Weber number immiscible droplet impact on a water pool: A background-oriented schlieren study on the interfacial dynamics and capillary wave characteristics

The problem of the science behind the impact of droplets on a liquid pool is quite relevant as it uncovers one of the the most abundant fluid interactions. A wave is generated at the impact and it traverses along the air-pool interface. This study provides spatiotemporal resolved whole-field topography of interface following the impact of an immiscible silicon oil droplet on water pool. We report different modes of interaction of the oil droplet based on pool height, droplet viscosity and Weber number, revealing their effect on the surface wave characteristics after the impact.