I love news about how we’re still studying (and attempting to classify knowledge of) things as mundane as how a droplet splash occurs and what patterns it might make! (Especially when awesome animated GIFs are involved!)
As a single raindrop falls to the ground, it can splash back up in a crown-like sheet, spraying smaller droplets from its rim before sinking back to the surface — all in the blink of an eye.
Now researchers at MIT have found a way to track the thickness of a droplet’s rim as it splashes up from a variety of surfaces. This incredibly specific measurement, they say, is key to predicting the number, size, and speed of smaller droplets that can be ejected from the rim, into the air.
Lydia Bourouiba, assistant professor of civil and environmental engineering and director of the Fluid Dynamics of Disease Transmission Laboratory at MIT, says the group’s results can be used to model the physics of sprays, such as pesticides that splash back up from crop leaves, or raindrops that may pick up and spread diseases as they bounce off contaminated surfaces.
The team found the theory holds up across a range of viscosities, including liquids as thin as water, and as thick as plasma or milk. It can also predict how the rim evolves as a droplet is splashed onto a variety of surfaces, with different geometries.
“The theory is not only universal across [surface] configurations, but can continue holding for a big family of industrial and biological fluids, for example,” Bourouiba says.