Tesla Valve

I thought that this Tesla valve video was exceptionally cool. The design is very simple, yet it performs a task that typically requires some sort of moving part. When designing for stability and reliability, static parts are typically preferred to dynamic parts, since they are less likely to malfunction during use. To be honest, I’m surprised that this Tesla Valve isn’t used more often. I expect that in the age of computer manufacturing, it will proliferate. To make a Tesla Valve in a machine shop seems like it would be a nightmare — very precise craftsmanship coupled with perfect engineering of the unit. However, with computer-aided high-pressure water jet cutting, this seems like a pretty simple device to manufacture. Also, the design appears to scale as pressure differences increase.

It does seem that this valve would fail to suppress a very low volumetric flow rate. If the fluid were able to trickle in to the valve rather than flow, the pressure system that the valve creates would not stop the fluid. Similarly: Imagine holding this valve parallel to the surface of a flowing river. If you horizontally submerged the valve half-way, such that half was in the water and half was out, the fluid should still be able to flow. Nonetheless, Tesla’s idea is ingenious for most systems where the geometry of flow is stable. What’s really cool is how it takes advantage of the no-slip boundary condition to direct the flow so that it only works in 1 direction. I’d be interested to find out how Tesla decided that 11 segments would be enough to stop the flow. How might that change based on the Reynolds number of the fluid flowing through it? If you could find an answer to that, you could optimize the system to minimize size and material waste. In all, I thought that the video presentation itself could use some work. Still, Tesla’s invention described in it is extremely cool.