Water Ring



The Water Ring


Tap Water on a Plate

Ordinary tap water  flows from a kitchen faucet onto the back of a dinner plate. At the impact point the water develops Radial Momentum, and fans out as a very thin (low-pressure) layer. Eventually, the thin sheet of radially-expanding water succumbs to surface friction and to counter-pressure from the higher depth water ahead. As the water level finally begins to rise, it decelerates even further and the process self-reinforces; the level quickly experiences the hydraulic jump, visible in the photo. The fluid dynamics are similar to those for radially expanding air in the levitator demonstration.