The whole field of fluidics is fascinating, including entire digital logic families that operate at kHz rates with no moving parts and no electricity, just air. I wrote a kragen-tol post about this in 2002 http://lists.canonical.org/pipermail/kragen-tol/2002-April/0..., when Air Logic still sold actual logic gates that ran on air, but since then Google Books has archived this June 1967 Popular Mechanics article, "How They've Taught a Stream of Air to Think": http://books.google.com.ar/books?id=jSEDAAAAMBAJ&pg=PA11..., and of course fluidics has become practically very important for on-chip microarrays. There's also a Wikipedia article now: http://en.wikipedia.org/wiki/Fluidics
I'm the one who made that 3D printed Tesla Valve shown in the pictures and video. I'm currently inventing a jet engine with no moving parts. If anyone wants to ask questions about the valve's workings or about Tesla, go right ahead.
Very cool, it would be interesting to build one (large) which would be wave pumped. You could cast it out of concrete I suspect. The idea being that waves would push into the end and then the flow back out would be self resisted, this would allow the wave energy to pump seawater up a bit. Then you provide a drain which runs through a micro-hydro station.
Would be fascinating to see what rate of wave action you would need to keep the flow going up hill.
On a pure art level building a pool on the beach that was filled with wave action like this would be kind of fun.
It's a cool idea, but you might want to just build it with a traditional valve. I think the Tesla valve relies on moving fluid. If you just submerged it half way water would leak out in the wrong direction. So it won't work well for applications in the style of Maxwell's Demon.
So there is a place off of Monetery I believe where there are pipes that extend out into the ocean from the beach. Waves coming into the beach push water up the pipes, the other end of the pipe up on the shore has sort of a pipe organ type end with a flapper valve so it plays one note when the water rushes in and another when it rushes out.
Imagine a square tube that at one end underwater is just an open pipe which connects with this square tube which goes up out of the water on the beach to a pool which is say 10' above the water line. The pool has a drain which feeds a square trough going back down into the water.
The trough has a micro-hydro wheel in it. Or just for fun a pelton water wheel type wheel which drives an animated sculpture.
The interesting question for me, is this; Can the Tesla valve reduce the back flow of sea water enough that the following wave arrives with the valve still holding water?
Intuitively you can see that if the valve is 'full' when the wave returns then the next wave will push its mass worth out the top of the valve. If the valve is say 'half' full then the next wave should fill it and every wave after that should dump a 'half' wave's worth of water into the pool. This would be a good problem to set up for students learning computational fluid dynamics (CFD) as they could vary things like the angle of the elements, their size, and their quantity and characterize the abilities of the valve for various fluids.
Well. Describing our ideas without a diagram breaks down rapidly. I imagined a valve bobbing in the water, slowly elevating the water in a reservoir with each wave undulation. Thinking about it more, the problem would be an eventual equalization in pressure. But of course, I read this paragraph again and there all ways of imagining what the words are saying. If we were to really understand each other, we'd need to whiteboard.
I'm not sure that a Tesla Valve would be all that useful for tapping wave motion now that I think of it. It might not work. One way to think of it is to imagine using a one way ball valve. That has helped me in the past from ascribing too much magic or revolutionary nature to the Tesla Valve.
That's a good idea. I've seen some of the wave generator concepts out there, and everyone seems to be trying different concepts for harnessing those oscillations. No one has it nailed down yet. One of the most intriguing mechanisms I've seen is this oscillating submersible wing: http://liquidr.com/technology/wave-glider-concept/
If you hold the valve vertically and pour water through the wrong side, water will eventually start to fall from the other side when all those cavities inside the valve get overflown --- is that correct?
My jet engine is unique. There are actually many no-moving-parts jets. Each with different drawbacks. A ramjet cannot start from a static position, mine can start from a static position.
If anyone is interested, there are some very cool no-moving-parts jets that aren't as well known as ramjets:
The lockwood hiller pulsejet is a pulsejet that doesn't need reed valves.
http://aardvark.co.nz/pjet/valveless.htm
The current use for Tesla Valves is in microfluidics. On the macro level, people generally use one way valves that have moving parts. To harness the flow of a fluid being acoustically pumped, I don't know what it would take.
You could make an array of them perpendicular to a plane. Perhaps, by etching them into silicon. On a macro scale, you could machine them with a CNC machine, or even with hand tools depending on your tolerances.
For sound, you energy density is rather low, so the material you wish to propel would have to be incredibly light. And you would probably have better luck trying to lift a plate of some super light material. The Tesla Valve is most useful as a device where you want to check the flow from moving one way.
Anywhere, where having a moving part is a pain in the butt, and you want a more robust system. When you're etching things into silicon, generally, you want to avoid have to make lots of tiny micromechanisms.
As a paddlewheel, it would probably not make sense to use the Tesla Valve. Turbines are well understood. If you want to make rotary motion, that's the way to go.
Have you made a rotationally symmetrical version of that flow, or are you going to try to make flattened jet? The biggest problem I've seen with valveless jets like this are that it works great in 2d, but rectangular cross-sections don't do well under high-pressures.
I have done lots of experiments with 3D versions of this valve. I even did some with a traveling rotation along the axis, so that it looked like a helix. Unfortunately, those were duds, though the looked beautiful.
My current jet engine work does not include a Tesla Valve, though much of it is inspired by it. When I began, I imagined using a pulse jet, and attaching an axialy rotated tesla valve to the front of it, in order to replace the reed valves. I eventually moved away from pulsed combustion though. Too noisy and not the pressure levels I wanted.
After seeing the pic of the valve you 3D printed, it would seem that making a jig for a router to cut that patern out would be better than printing the valve itself.
And seems like routing one out of aluminum on a CNC would be good as well.
My late-night reading currently consists of the book "Wizard: The Life and Times of Nikola Tesla; Biography of a Genius" by Marc J. Seifer. For anyone looking to learn more about the man, this seems to be the most comprehensive biography available. While only half through it so far, it's been an enjoyable and enlightening read.
The author's occasional dry humour is also quite welcome. Here's a sample:
"Due to his meager funds and general inability to budget himself, Tesla had but one suit, which had withered from use. It was the time of a religious festival, and Szigeti inquired what Tesla would be wearing. Stuck for an answer, the youthful inventor came upon the clever idea of turning his suit inside out, planning thereby to show up with a seemingly new set of clothes. All night was spent tailoring and ironing. But when one starts with a wrong premise, no amount of patching can right the problem. The outfit looked ridiculous, and Tesla stayed home instead."
He had his own vision of a "singularity" basically interconnectedness of all human kind across earth to "rid ourselves" of war. Free energy, etc. Held full models of his machines and ideas in his head (spatially fascinating) before construction.
Several nervous of mental breakdowns when over-working, strange debilitating flashes of light, etc. Probably some brain chemistry idiosyncrasies.
Right, I thought the idea of Tesla, as a wizard of science among mere squabbling magicians, a fun plot notion. That they dealt with him, almost alone and in his secret keep, surrounded by the mysteries of his work, a wonderful spin on the mythos surrounding Tesla.
It helps that Tesla's personality was bit off in real life, and he did things that even today we think of as a kind of magic.
Of course in the movie what he built was impossible, but the notion that "any sufficiently advanced technology is indistinguishable from magic" kept creeping into my mind.
I have the feeling that, to an engineer/researcher who is well versed in fluid-dynamics, this sort of thing wont seem as ingenious - my guess is that it's at the analogous level of a waveguide.
They also work. The Tesla valve allows a fair amount of bleed through, and unlike valves with moving parts you can't prevent that from stacking them. In other words it becomes less efficient as the presser differential decreases.
There might be some interesting applications for a device that passes two things, say a fluid and a gas, in one direction and resists the fluid (but not the gas) in another.
"But those sources you list describe several types of check valves, all of which have moving parts."
Most all check valves use moving parts; the Tesla Valve is novel because it does not.
I added the sources for those that might want to satisfy their curiosity when thinking, "I wonder what type of device a Tesla Valve is?"
Although the Tesla Valve does not use moving parts, that does not mean that it is not classified as a check valve. Tesla's descriptions from his patent [1] describe the valve as only permitting flow through it in one direction, which is the essential operation of a check valve:
"[...] a series of recesses or pockets with surfaces that reverse a fluid tending to flow in one direction therein and thereby check or prevent flow of the fluid in that direction." (Page 5, Item 3)
"[...] and thereby check their progress when impelled in the opposite sense." (Page 5, Item 5)
"[...] reverse such fluid impulses when impelled in the opposite direction and check their flow." (Page 5, Item 6)
HN style is to go really light on joking and really heavy on information. It can make for some dry reading sometimes, but it's better than Reddit where informative discussion can get drowned out by jokes, pun threads and snark.
So people tend to downvote witty comments unless they find them very funny.
Furthermore, complaining about downvotes is a gamble. The odds are in favor of receiving more downvotes if you complain, though sometimes it works out the other way. However, the odds are especially biased for more downvotes if you make some sweeping statement (or "question") about the entire community as a reason for the downvotes.
That's pretty cool. The curved side channel actually pushes the main flow into the next side channel.
I wonder if a fractal version of this would work better. And what if there were side channels on the top and bottom too.
Of course, this will always pass some fluid. but if you need a complete shutoff valve, combining it with the tesla valve would allow you to use a smaller one and makes its failure less traumatic.
In regard to a fractal design being more efficient, you have to check out these topology optimized valves. They are really beautiful and peculiar, and have many branching channels to optimize their efficiency. http://www.senlin41.org/topology-optimization-of-tesla-type-...
I find that device fascinating too. That's why I designed the 3D printed Tesla Valve in the article. Things with no moving parts are amazing. Especially the esoteric ones that seem forgotten by time because other technologies progressed ahead of them.
Just imagine the day we get cheap 3D printers. We see this article on the internet on the Tesla Valve and want to try it out ourselves, so we download the blueprint and send it to our personal printer, which prints a copy of the Tesla Valve and then we play with it ourselves. I am guessing there are so many (expired) patents out there that, just like this one, can be converted to a blue print and everyone would get to experiment with it, instead of only large companies with enough cash to customise expensive equipment for it.
That's very elegant. It's amazing (and a little terrifying) to think that he may very well have been able to mentally visualize the fluid dynamics to some extent. It's not like he was consciously solving navier-stokes, but it's still incredible what some human minds are capable of.
But then, he was thinking a lot about electron flow and built up a good intuition that had wider application. That doesn't make it any less amazing to me though. I'd like to be able to do that.
Tesla was an amazing man. Though our tools are impressive, I am still far more impressed by the human mind. A good use of tools relies on the exploration of consciousness. If both are not in harmony, we get mediocre results.
In the case of Da Vinci, Einstein, Tesla and a select number of others I think that thinking of them that way is well justified.
The general idea is that if the time is ripe for an idea then someone somewhere will have it, and if that someone would not exist someone else will have the idea a short while after.
But for the men mentioned above I highly doubt that would be the case, they were both way ahead of the curve at the time.
Yes, it seems better as a technique to introduce bias to flow than to restrict it altogether---valve-like, but not exactly a valve. Sufficient for a lot of valve applications, though, and the lack of moving parts is reeeeeally nice.
The Tesla Valve is a leaky valve, which is why we still use one way valves with moving parts. The amount of leakage depends on the design of the valve and how well it suits the incoming fluid. A faster fluid will result in a different looking valve compared to a slower fluid. The valves design would also change based on the viscosity of the fluid.
Is the unidirectional flow property dependent on the pressure gradient at both ends? It seems that at low pressure differences you could still get flow in the reverse direction. Yet, at high pressures I imagine you would see some leakage, too. Does it only work for medium pressures?
In will work in many regimes. In the microfluidic literature, the valve is judged by its diodicity. Different flow rates, sizes, and viscosity, results in different geometry for the tesla valve.
Yes. It also works with incompressible flows. I have yet to give mine a test with water. I want to build an acrylic window for it first, and ink the incoming water.
[1] I'm a bit confused as to whether it was genuinely an autobiography, or a compilation of articles. Either way, it was interesting to read, though very light on technical details.
There are also some versions on the internet which include fake sentences inserted later by some religious zealot mentioning "God, Divine Being." Take care not to link to those.
1. All one-way valves depend on flow. If there is a higher pressure from A to B. And that's the direction of resistance, then in a valve with moving parts, a ball or diaphragm of some sort would be pushed against a lip, and the flow would stop. That still depends on a pressure difference where flow was traveling from some high pressure point to some low pressure point. Let's say that valve was off design for the flow rate. It may not have enough pressure to seal, and it would still be leaky. The Tesla Valve's performance is measured by its diodicity, and it has to be matched to the conditions it's supposed to exist in. If it was really well designed, it's diodicity would be very high and thus leakage would be minimized. From an engineering standpoint it still usually makes sense to use valves with moving parts on your example lox tank. As the main way of checking flow, they are well understood and very reliable. However, if you are in a situation where a moving part is a negative, like in microfluidics, a Tesla valve might make more sense.
2. Liquids and gases have different viscosity, so the Tesla Valve would be different for each fluid and flow regime. I am unfamiliar with this series-of-petals geometry you are remembering. However, it reminds me of this excellent work done on optimizing topology for different Reynolds numbers in Tesla Valves: http://www.senlin41.org/topology-optimization-of-tesla-type-...
3. One of the original intents of the valve was for Tesla's Bladeless Disc Turbine. In Tesla's time, materials were not what they are now, and thus valves with moving parts were not as reliable. Also, getting a valve that can close and open with high frequency is not always easy. The valvular conduit that Tesla designed was his solution to this problem.
Thanks for the book reference. I read "Wizard: The Life and Times of Nikola Tesla" But I hadn't seen this other book. I might pick it up.
o2sd: Something caused your account to autokill your messages, so no one can reply to you anymore, and no one will see your posts if they don't have showdead on.
I'm replying here because it's the only place I can contact you. And I don't see any spam in your account.
