Dynamics of freely suspended drops translating through miscible environments

Our work focuses on an experimental investigation of droplets freely rising through a miscible, more viscous liquid. We report observations of water droplets rising through glycerol and corn syrup, which are common household ingredients. Immediately after the drops are formed, they take on prolate shapes and rise with constant velocity without expanding in size. However, after a critical time predicted by our scaling arguments, the drops continually grow into oblate spheroids, and as they mix with the ambient liquid, their volume increases and their velocity decreases, eventually following power laws. We present scaling relations that explain the main observed phenomena. However, the power laws governing the rate of the volumetric increase and the velocity decrease, namely, t(1/2) and t(-1/2), respectively, remain points of further investigation. Published under license by AIP Publishing.

Automated summary

The study focuses on experimental investigation of droplets rising through viscous liquid, observing that droplets change shape from prolate to oblate spheroids as they mix with the ambient liquid, with their volume increasing and velocity decreasing according to power laws. The scaling relations explain the observed phenomena, but further investigation is needed on the power laws governing the rate of volumetric increase and velocity decrease.