This short film offers an artistic look at the phenomenon of the water bridge. When subjected to a large voltage difference, such as the 30 kV used in the film, flow can be induced between water in two separated beakers. This creates a water bridge seemingly floating on air. There are two main forces opposing the bridge: gravity, which causes it to sag, and capillary action, which tries to thin the bridge to the point where it will break into droplets. These forces are countered by polarization forces induced at the liquid interface due to the electrical field separating the water’s positive and negative charges. This separation of charges creates normal stresses along the water surface, which counteracts the gravitational and capillary forces on the bridge. The artist has done a beautiful job of capturing the unsteadiness and delicacy of the phenomenon. (Video credit: Lariontsev Nick)
Artist Sachiko Kodama is known for her mesmerizing ferrofluid sculptures. Ferrofluids are a colloidal liquid consisting of nanoscale ferromagnetic particles and a carrier fluid such as water or oil. They can react strongly to magnetic fields, forming spikes, brain-like whorls, and even labyrinths. (Photo credits: Sachiko Kodama; via freshphotons)
Nothing quite compares to the beauty of fluid dynamics on astronomical scales. What you see here are raw photographs of recent storms at Saturn’s north pole. The recent change in Saturnian seasons has afforded Cassini a sunlit view of the northern pole, which had previously lain in darkness. A roiling vortex filled with clouds being twisted and sheared was revealed near the center of its famed polar hexagon. (Photo credit: NASA/JPL-Caltech/Space Science Institute; submitted by J. Shoer)
These images from a numerical simulation of a mixing layer between fluids of different density show the development and breakdown to Kelvin-Helmholtz waves. The black fluid is 3 times denser than the white fluid, and, as the two layers shear past one another, billow-like waves form (Fig 1(a)). Inside those billows, secondary and even tertiary billows form (Fig 1(a) and (b)). Fig 1 (c)-(e) show successive closeups on these waves, showing their beautiful fractal-like structure. (Photo credit: J. Fontane et al, 2008 Gallery of Fluid Motion) #
This video creates the illusion of a jet of water frozen in mid-air. The effect is achieved by vibrating the water at the frequency of the speaker, then filming at a frame rate identical to the vibrational frequency. Thus the water pulses at the exact rate that the camera captures images, making the water appear stationary even though it is moving. (submitted by Simon H)
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)
