Fountain Parabolas

Shooting graceful arcs of water into the air, fountains can offer lessons in geometric spectacle. The fountain at the National Gallery of Art Sculpture Garden in Washington, D.C., is a notable example.

The circular fountain at the National Gallery of Art Sculpture Garden shoots parabolic streams of water from its circumference toward its center.

One factor that makes some fountains more spectacular than others is the angle of the jets that send water in parabolic paths. Angles between 50 and 60 degrees seem to produce particularly striking effects, either enclosing the largest possible volume or having the greatest total surface area (see "The Geometric Spectacle of Water Fountains").

Water jets shooting from standard nozzles quickly spread out and lose definition as parabolas.

In most fountains, the water jets become wider and fuzzier as they shoot farther out, losing their precise definition as parabolas. One particularly dramatic exception is an indoor fountain in the Edward H. McNamara Terminal at Detroit Metropolitan Wayne County Airport.

Precisely defined laminar (turbulence-free) flow produces jets of rapidly moving water that look motionless, like glass rods bent into parabolas, as in this fountain at Detroit Metropolitan Wayne County Airport.

The water jets look like bent glass rods. Each narrow jet of rapidly flowing water retains its circular cross section throughout its trajectory. When the flow is interrupted, you can trace the final segment all the way to the end, still following its natural arc. At times, the computer-orchestrated water choreography makes the segmented water jets look like exquisitely slim, silvery fish leaping through the air.

The fountain was designed by WET Design, a company based in Universal City, Calif., that specializes in manipulating water to spectacular effect. WET stands for Water Entertainment Technologies. A key element of these fountain designs is a special nozzle, invented by Mark Fuller (one of the founders of WET Design), that generates streamline (or laminar or turbulence-free) flow rather than the spray typical of most nozzles.

Jets of rapidly moving water emerge from special nozzles embedded in a black granite slab.

Photos by I. Peterson