Impact of an air-in-liquid compound drop onto a liquid surface

We study experimentally the dynamics of a liquid drop containing an air bubble falling onto a pool of the same liquid. We first develop a drop-on-demand setup capable of forming repeatable compound drops without any surfactant. Then, we investigate the impact dynamics above and below the pool surface combining two high-speed cameras. We identify three different regimes as the impact height increases. At low impact velocities, the bubble is engulfed into the pool. Above a critical impact velocity, the bubble bursts during impact. For higher falling heights, the bubble ruptures before reaching the pool due to air drag decelerating the compound drop.