Droplet Breakup Against a Thin Wire

We observe oil droplets rising in a tank of water, where the droplets collide with a thin wire as they rise. When droplets encounter this nonwetting obstacle, sometimes the droplet detours around the wire, and sometimes the droplet breaks into two. Droplets are more likely to break up when they are moving faster (larger capillary number), when they are larger diameter, and when they collide in a symmetric fashion against the wire. These observations are similar to previous 2D experimental results from our laboratory. In this experiment, we observe the three-dimensional shapes of the droplets as they interact with the wire. This research can help us understand situations where droplets move through porous media such as pollutants moving through soil and other natural environments.