Researchers from New York University recently revisited a 100-year-old one-way water valve design developed by Nikola Tesla, and concluded that it could be used today to increase motor efficiency by using energy that would otherwise go to waste, a New Scientist report explains.
Nikola Tesla's "valvular conduit" design, also known today as the "Tesla valve", was patented in 1920. The design, essentially a series of interconnected keychain-shaped loops, was created to enable fluid to pass in only one direction with no moving parts.
If you send fluid through one end of the "valvular conduit" it loops back in on itself, impeding the flow. Send it in the other direction, however, and it flows freely.
"While Tesla is known as a wizard of electric currents and electrical circuits, his lesser-known work to control flows or fluid currents was truly ahead of its time," Leif Ristroph, an associate professor in New York University, explained in a press release.
In order to test the valve, Ristroph and a team used Tesla's original design to build a 30-centimeter-long version. The team then measured the flow in both directions at different pressures.
AC applications adapted for one-way fluid valve
Interestingly, the researchers found that their version of the valve made the fluid flow two times slower when going in the wrong direction — Tesla's original patent stated the design made water flow 200 times slower when going in the wrong direction.
They also found that the valve works best when the flow of water comes in pulses or oscillation, which are converted by the device into a smoothly directed output of fluid.
The researchers explained that this pulse action closely resembles the process by which AC-DC converters — also patented by Tesla — transform the alternating current to direct current. When AC electricity is converted to DC, electrons stop reversing their direction and effectively flow in a loop.
"We think this is what Tesla had in mind for the device, since he was thinking about analogous operations with electrical currents," Ristroph stated. "He in fact is most famous for inventing the AC motor as well as an AC-DC converter."
In their study, the NYU team explained that the design could be utilized today to harness otherwise wasted energy from machine and motor vibrations in order to efficiently pump fuel, coolant, lubricant, and other fluids.
Much in the same way that Tesla's pioneering work with alternating currents might lead to new innovations such as EV-charging roads, the "valvular conduit" might be used to increase the efficiency of the machines of the future.