A head-on collision between two water droplets just twice the thickness of a human hair results in this flattened pancake of fluid. Simulating such collisions allows researchers to understand how this sheet of liquid expands and contracts and how droplets splinter off its rim.
Coral polyps sport tiny hair-like appendages called cilia, which they beat rhythmically in the water. Researcher used fluorescent beads to track the flow of water around coral polyps, finding mixing that is perpendicular to the water surface. This fluid motion may enhance photosynthesis and protect the coral from nasty microbes.
Researchers inspired by watching children clap wet hands studied the dynamics of water "clapped" between two solid plates. They found that water flow outwards in a sheet with a thick rim, seen here. In another instant, the rim will begin to dissolve into fast-moving droplets
Liquid vortices (red) interact with a solid wall to create secondary vortices (green). This research, sponsored by the Office of Naval Research, has practical applications for designing vehicles that move through air and water.
This whirlwind of vortices is created by water moving around a cylinder.
Water moving around a cylinder forms complex vortex patterns.
A burst of air in water creates this single bubble, photographed in multiple exposures as it rises to the top of the tank. Pressure differences between the top and bottom of the bubble transform it into a donut shape.
This starfish-shaped wave was created by vertically vibrating liquid in a container. The wave pattern alternates between looking like a star and looking like a pentagon.
A straight stream of honey coils as it his the surface of liquid water in a crystal goblet. This phenomenon is called "liquid rope coiling."
A specialized inlet and tube creates this disc of water, which would make a lovely addition to a garden fountain, researchers say.
A beautiful blue-and-white mix of water and an elastic solution made of polyacrylamide, which is used in the process of making soft contact lenses. The image shows the water and the blue-dyed polyacrylamide undergoing a "hydraulic jump," which occurs when a fluid changes from a fast, parallel (or laminar) flow and moves into a slow, turbulent flow.
A magnetic fluid is called a ferrofluid. Here, magnetic fields and temperature conspire to disrupt the flow of a ferrofluid, creating linear patterns.