The splashes from droplets impacting jets create truly mesmerizing liquid sculptures. Corrie White is one of the masters of this type of high-speed macro photography. Her work captures the instantaneous battles between viscosity, surface tension, and inertia. The fantastic structure seen here through the falling droplets is created by a series of drops timed so that the later ones strike the Worthington jet produced by the initial drop’s impact. (Photo credit: Corrie White)
The breakup of impinging jets into droplets (also called atomization) and the subsequent dynamics of those droplets are important in applications like jet and rocket engines where the mixing of liquid fuel with oxygen is necessary for efficient combustion. This video showcases recent efforts in high fidelity numerical simulation and modeling of such flows. The complexity of the problem requires clever ways of reducing the computational efforts required. One such method uses adaptive meshing to concentrate grid points in areas where variables are changing quickly while leaving the grid sparse in areas of less interest. Because the flow is constantly evolving, the mesh must be able to adapt as the simulation steps forward in time. Even so, such calculations typically require supercomputers to complete. (Video credit: X. Chen et al)
(Source: arxiv.org)
This high-speed video shows the apparatus often used by photographers for fluid sculptures created from droplet collisions. As amazing as these formations are in still images, seeing their evolution at 5,000 fps is even more lovely.
Droplet collisions captured instantaneously create beautiful fluid sculptures that, though common, are too fast for the human eye. Here a bubble was blown onto the surface of the fluid, then a droplet was released to fall into the center of the bubble, bursting it. As that droplet rebounded in a Worthington jet, a second droplet was released and impacted the jet, creating the umbrella-like shape in the center. See Liquid Droplet Art for more photos. (Photo credit: Corrie White and Igor Kliakhandler) #
This stereo 3D photo shows the Worthington jet ejected when a droplet impacts a pool. The flat crowning drop is formed from an ejected droplet colliding with a falling droplet.
When a droplet falls into a pool of similar fluid, one often observes a crown-like inmpact effect. This student video shows high-speed footage of different fluids crowning and explores the effects of surface tension on crown breakup.
As those of us in Texas get drenched by Tropical Storm Hermine, it’s worth taking a moment to enjoy the beauty of each rain drop hitting a puddle.
Here is another take on what happens when a drop of water falls into a larger pool.
Droplet collisions, usually with water or milk, are popular with photographers for their artistic value. As stunning as these still images are, high-speed video makes the effect even better.
Photo credit; See also: Liquid sculpture and Flickr
Celebrating the physics of all that flows. 
