Stephanie and Edward Vinces own and operate a computers sales and consulting business in Pacific, California, and are avid makers and artists in their leisure time. Their work ranges from robotics to statuary and garden art. If you were at Maker Faire Bay Area 2013, you may recall the laminar flow fountain they brought last year. This year the Vinces are back with a bigger, badder double-jet fountain design, of which Edward writes:
I have made a larger nozzle for the garden with a 9mm orifice but a small unit is much harder because the of the Reynolds number rules where aerodynamic flow is not scalable. There is an electric pump in the receiving bowl, it feeds water to the nozzle assembly that goes first through two air chambers to filter the pulses of the pump motor, then into the nozzle that goes first through a series of coarse filters to filter initial turbulent flow, then throuigh a stack of fine drinking straws to create a laminar flow, and finally out thru a 4mm orifice that has been machined and polished to a sharp edge.
Ordinary flow is turbulent, meaning it has lots of cross-currents perpendicular to the flow direction, including swirls and eddies. In ideal laminar or streamline flow, turbulence is absent, and the fluid — whether air, water, or some other gas or liquid — flows in nice, orderly parallel layers without lateral mixing. Making machines operate in a laminar-flow “regime” requires careful attention to fluid dynamics during the design, but can pay off in all kinds of useful and beautiful ways.
One popular low-cost application is a DIY laminar flow nozzle capable of projecting an unbroken “rod” of water over great distances. So-called “jumping fountains,” in which these smooth jets of water appear to hop from one location to another, are created using laminar flow nozzles that operate on this same principle.
You can see more of the Vinces’ work at inventedart.com.