A Tesla valve allows a fluid to flow preferentially in one direction, without moving parts

Wednesday, December 18th, 2019

In 1920, Nikola Tesla was awarded U.S. Patent 1,329,559 for his valvular conduit, or Tesla valve, which allows a fluid to flow preferentially in one direction, without moving parts:


  1. TRX says:

    The device pictured is usually known as a “fluidic diode,” and variants have been used for things ranging from hydraulic analog computers (yes, water as the working medium!) to sound suppressors for firearms.


    By the time fluidics became well-developed, most of the niches it might have occupied were already filled by electrical devices, so it’s mostly a curiosity.

    On the other hand, fluidic devices can work without electricity, are immune to EMP and hard radiation, and are easily made without dependence on a complex technological infrastructure. They’re not a universal solution, but they can be a useful extra string for the design engineer’s bow.

  2. Sam J. says:

    I read somewhere that fluidic control systems are used for the thrust reversing doors on jet planes. Heat resistant and robust was the reasons chosen.

  3. Roy J. says:

    Thrust reversers on modern commercial airliners are generally controlled by electric motors driving rotating cables in sheathes. The cables are somewhat flexible so they can wrap around the cowling to get to the geared actuators. Usually there is a front fan reverser and rear hot section reverser. Hydraulics would be prone to leaking and in the hot section the fluid would cook in the lines when it’s not being pumped.

  4. Sam J. says:

    I should have said some thrust reversers. I don’t remember which planes.

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