Abstract
We study numerically the dynamics of an air-in-liquid compound drop impacting onto a solid surface. We demonstrate that the addition of a bubble in the drop decreases its maximum spreading. This decrease is explained by the lower kinetic energy of the drop, but also amplified by the formation of a vertical jet emerging from its center, and a relative increase in the viscous dissipation. We propose a new theory describing the maximum spreading of an air-in-liquid compound drop by including these effects into modified Weber and Reynolds numbers. Finally, we demonstrate that the eventual bursting of the bubble does not significantly affect the maximum spreading diameter, by characterizing the bubble bursting and performing additional simulations where the bursting of the bubble is prevented.