Wind-driven mixing of drops on fibers

Drops on fibers in crossflows have complex dynamics. At an intermediate Reynolds number, the imposed crossflow leads to a wake asymmetry which induces translation along the fiber. As the drops move, they deposit thin films on the fiber. These thin films can be picked up by other drops. Using fluorescent and brightfield imaging, we study the mixing of these films inside two adjacent drops. We generalize our results to multiple drops on a fiber and rationalize the mixing with analytical and numerical models for the films deposited on the fibers and the corresponding internal flows in droplets.