Nikola Tesla was a Serbian electrical/machanical engineer and one of the greatest inventors of all time. He is best known for his contributions to the design of the modern alternating current (AC) electricity supply system and made dozens of breakthroughs in the production, transmission and application of electric power.
Tesla was born in 1856 in Smiljan, Croatia. He studied engineering and physics in the 1870s, gaining practical experience in the early 1880s working in telephony and at Continental Edison in the new electric power industry. In 1882, while on a walk, he came up with the idea for a brushless AC motor and made the first sketches of its rotating electromagnets in the sand of the path. Later that year the young inventor moved to Paris and got a job repairing direct current (DC) power plants. In the year 1884 he emigrated to the U.S. and became a citizen. He worked for a while at the Edison Machine Works in New York City before he struck out on his own. In 1887 and 1888 he was already granted more than 30 patents for his inventions. Because of that he got invited to address the American Institute of Electrical Engineers on his work. His lecture got the attention of George Westinghouse who launched the first AC power system near Boston and was Edison’s major competitor. Westinghouse soon hired Tesla and licensed the patents for his AC motor.
In the 1890s Tesla invented a wireless-controlled boat, electric oscillators, electrical discharge tubes and a high-voltage transformer known as the Tesla coil. He also experimented with early X-ray imaging, gave short-range demonstrations of radio communication already two years before Guglielmo Marconi. In 1893 the Chicago World Fair was illuminated using Nikola Tesla’s inventions for A/C electricity and fluorescent lighting, it was a spectacle that amazed the world. Tesla also partnered with General Electric, installing AC generators at Niagara Falls to create the first modern power station.
In 1920 Tesla filed the patent for his “valvular conduit”. In its essence it is a pipe with an intricate design consisting of a series of diverting teardrop-shaped loops, which forces fluid moving in one direction to loop back on itself at various points. When water flows into the loops, it becomes turbulent and slows down, halting the flow. However if the water runs in the opposite direction, it doesn’t enter the loops and thus flows freely through the pipe. The great advantage of this design is that it has absolutely no moving parts which could wear out like the springs and other mechanisms on conventional check valves.
Leif Ristroph, an associate professor at New York University’s Courant Institute of Mathematical Sciences is the senior author of a new paper in Nature Communications that looks at how the Tesla valve works and how it could be used in the 21st century.
“It has been known about and has been used in some applications, or at least proposed for use. But no one had ever really done the thorough hydrodynamics work on it to figure out how it works, how well it works,” says Ristroph.
By experimenting with replicas of Tesla’s valve, the researchers found that the flow-blocking capabilities of the valve “turn on” by creating turbulence and swirling vortices in the conduit at a certain rate of flow. They also found that the valve works better with a flow that isn’t steady but instead comes in oscillations or pulses. This would make it an ideal candidate for use in high-vibration environments.
While Tesla claimed in his patent that his valve could make water flow 200 times slower in one direction than the other, the researchers found that their replica version only made it two times slower. It is still unclear whether he actually made and tested it, because there is no documentation available today. Even though the effect was much lower as Tesla claimed, the valve is still a very useful design, since it has no moving parts and thus it could be maintenance-free. A conventional check valve can wear out and fail after extended use, so this 100 year old design could now replace modern valve systems.