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The Tesla Valve: One Way Flow With No Moving Parts

405 points by iamwil 15y ago

megaman821 15y ago
How Telsa came up with most the things he did are beyond me. I have always thought he was the smartest man that has ever lived.
- loceng 15y ago
  He came from the future to try to prevent us from destroying our planet with pollution and global warming.
  - samstave 15y ago
    As much as I love Tesla, if this is true - he has failed :(
  - loceng 15y ago
    No sense of humour here on HN?
    - techiferous 15y ago
      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.
    - Jach 15y ago
      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.
- backprojection 15y ago
  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. No doubt that Tesla was a bright person though.
  - Arjuna 15y ago
    "[...] my guess is that it's at the analogous level of a waveguide." In the field of fluid dynamics, it is referred to as a check valve. [1][2] [1] http://en.wikipedia.org/wiki/Check_valve http://en.wikipedia.org/wiki/Check_valve [2] http://www.spiraxsarco.com/resources/steam-engineering-tutorials/pipeline-ancillaries/check-valves.asp http://www.spiraxsarco.com/resources/steam-engineering-tutor...
    - marshray 15y ago
      Well the function of restricting flow in one direction is well known. But those sources you list describe several types of check valves, all of which have moving parts.
      - Retric 15y ago
        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.
        marshray 15y ago
        That bleed is also a function of viscosity. 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.
      - Arjuna 15y ago
        "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) [1] http://www.google.com/patents?id=Lt1PAAAAEBAJ http://www.google.com/patents?id=Lt1PAAAAEBAJ
- idonthack 15y ago
  Did you know that Tesla created the equivalent of a waterwheel that tapped the energy of Earth's motion through the coelestial aether? Unfortunately, the resulting drag force was larger than he'd predicted, and after his experiments introduced a full extra day in 1893 (February 31, 1893 - google it), he was forced to stop his experiments. The original wheel is still on display in his home town of Smiljan. On special occasions, it is started up and let spin freely, without a load attached. To fix the mess he made, Tesla had to use the energy he'd stored up from the wheel (in a huge bank of capacitors - creating this was such a feat that the unit for capacitance is now named in his honor) to actually drive the wheel and restore the Earth's proper rotational period. Of course, the transfer wasn't without loss, which is why years divisible by 100 do not have leap days any longer.
learc83 15y ago
From the video it looked like there was still some airflow in the reverse direction.
- blahedo 15y ago
  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.
  - backprojection 15y ago
    Looks like the shape tries to maximize turbulence in one direction, and minimize it in the other. Probably it would be an effective mixing device too.
    - imperator 15y ago
      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.
damoncali 15y ago
From the comments: Reminds me of http://en.wikipedia.org/wiki/Vortex_tube http://en.wikipedia.org/wiki/Vortex_tube Another simple yet fascinating device
- imperator 15y ago
  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.
mikeknoop 15y ago
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?
- imperator 15y ago
  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.
georgieporgie 15y ago
If you haven't read Tesla's autobiography[1], I highly recommend it. http://www.tfcbooks.com/special/my_inventions_index.htm http://www.tfcbooks.com/special/my_inventions_index.htm [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.
- acqq 15y ago
  It is a collection of articles for the "Electrical Experimenter" magazine: http://en.wikipedia.org/wiki/Electrical_Experimenter http://en.wikipedia.org/wiki/Electrical_Experimenter The articles were written by Tesla and they are autobiographical. 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.
stretchwithme 15y ago
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.
- imperator 15y ago
  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-microvalve/ http://www.senlin41.org/topology-optimization-of-tesla-type-...
  - stretchwithme 15y ago
    nice. thanks!
imperator 15y ago
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.
- recusancy 15y ago
  You should do an AMA on reddit.
  - imperator 15y ago
    Someone did a TIL on reddit and I popped in to answer questions there, too. http://www.reddit.com/r/todayilearned/comments/obyxj/til_that_nicola_tesla_invented_a_valve_that_lets/ http://www.reddit.com/r/todayilearned/comments/obyxj/til_tha...
- apu 15y ago
  I'm currently inventing a jet engine with no moving parts A ramjet?
  - imperator 15y ago
    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 http://aardvark.co.nz/pjet/valveless.htm The Gluhareff Pressure jet is also a neat example. https://en.wikipedia.org/wiki/Gluhareff_Pressure_Jet https://en.wikipedia.org/wiki/Gluhareff_Pressure_Jet
    - sbierwagen 15y ago
      A pulsejet based on the Tesla valve? So, like that prototype Bruce Simpson was talking about ten years ago? https://webcache.googleusercontent.com/search?q=cache:UX5eNgncG3MJ:aardvark.co.nz/pjet/xjet.shtml+&cd=1&hl=en&ct=clnk&gl=us&client=firefox-a https://webcache.googleusercontent.com/search?q=cache:UX5eNg...
Tycho 15y ago
Can someone post a link to the desktop version? Site is unreadable on iPad.
- mdonahoe 15y ago
  Scroll down and turn off The mobile version of the Wordpress theme.
meric 15y ago
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.
- imperator 15y ago
  If you are still waiting for that day, you can get the valve 3D printed now from my shop: http://www.shapeways.com/model/292339/tesla_valve.html http://www.shapeways.com/model/292339/tesla_valve.html And if you already have a 3D printer, you can get the files free here: http://www.thingiverse.com/thing:16919 http://www.thingiverse.com/thing:16919
o2sd 15y ago
I remember reading about this valve in 'Man Out Of Time'[1], (great book BTW, highly recommended). Well, you said ask questions. :) 1) I seem to recall this valve only works when there is flow, so if you need to store liquid oxygen, for example, you would still need a check valve on the tank. Is that correct? 2) I think there is another variation on this valve for liquids, is that right? This version is for gasses, the valve for liquids looks like a series of petals. Is that right or did I imagine it? 3) Was the original intent of this valve to prevent back pressure from the blade turbine? Thanks, o2sd [1] http://www.bookdepository.com/Tesla-Man-out-Time-Margaret-Cheney/9780743215367 http://www.bookdepository.com/Tesla-Man-out-Time-Margaret-Ch...
- imperator 15y ago
  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-microvalve/ 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.
thusly 15y ago
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."
- salemh 15y ago
  His own biography (somewhat stilted writing, the constant "I" self-referrals, but, dense and very interesting): My Inventions: The Autobiography of Nikola Tesla http://www.amazon.com/My-Inventions-Autobiography-Nikola-Tesla/dp/0910077002/ref=sr_1_1?s=books&ie=UTF8&qid=1328411812&sr=1-1 http://www.amazon.com/My-Inventions-Autobiography-Nikola-Tes... 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.
- bane 15y ago
  My late-night reading currently consists of the book "Wizard: The Life and Times of Nikola Tesla I'd recommend "The Prestige" http://www.imdb.com/title/tt0482571/ http://www.imdb.com/title/tt0482571/ which has a fascinating portrayal of Tesla as a kind of mad techno Wizard (played by David Bowie of all people).
  - thret 15y ago
    The Prestige is complete fiction that merely uses his name because he is recognisable as a practical genius.
rbanffy 15y ago
Does it work with incompressible fluids? Can someone test one with water?
- imperator 15y ago
  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.
kragen 15y ago
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/000706.html 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=PA118&lpg=PA118&dq=taught+air+to+think+fluidics&source=bl&ots=Qt70QlAjgX&sig=axEWaqYpR8KHH76sJ4LOfIRTDoI&hl=es-419&sa=X&ei=evQtT861JomDtge7qoWNBg&ved=0CCYQ6AEwAA#v=onepage&q&f=false 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 http://en.wikipedia.org/wiki/Fluidics
- gjm11 15y ago
  See also: http://catb.org/jargon/html/G/glitch.html#crunchly73-06-04 http://catb.org/jargon/html/G/glitch.html#crunchly73-06-04 and follow the next-cartoon chain from there. I particularly like http://catb.org/jargon/html/N/number-crunching.html#crunchly74-12-25 http://catb.org/jargon/html/N/number-crunching.html#crunchly... .
mrstinton 15y ago
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.
- imperator 15y ago
  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.
- gcb 15y ago
  a patent is a record of the working device, not the process used to get to it. thinking of anyone as a supernatural genius is nonsense. most of the time.
  - jacquesm 15y ago
    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.

405 points by iamwil 15y ago

How Telsa came up with most the things he did are beyond me. I have always thought he was the smartest man that has ever lived.

loceng 15y ago
He came from the future to try to prevent us from destroying our planet with pollution and global warming.
- samstave 15y ago
  As much as I love Tesla, if this is true - he has failed :(
- loceng 15y ago
  No sense of humour here on HN?
  - techiferous 15y ago
    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.
  - Jach 15y ago
    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.
backprojection 15y ago
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. No doubt that Tesla was a bright person though.
- Arjuna 15y ago
  "[...] my guess is that it's at the analogous level of a waveguide." In the field of fluid dynamics, it is referred to as a check valve. [1][2] [1] http://en.wikipedia.org/wiki/Check_valve http://en.wikipedia.org/wiki/Check_valve [2] http://www.spiraxsarco.com/resources/steam-engineering-tutorials/pipeline-ancillaries/check-valves.asp http://www.spiraxsarco.com/resources/steam-engineering-tutor...
  - marshray 15y ago
    Well the function of restricting flow in one direction is well known. But those sources you list describe several types of check valves, all of which have moving parts.
    - Retric 15y ago
      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.
      - marshray 15y ago
        That bleed is also a function of viscosity. 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.
    - Arjuna 15y ago
      "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) [1] http://www.google.com/patents?id=Lt1PAAAAEBAJ http://www.google.com/patents?id=Lt1PAAAAEBAJ
idonthack 15y ago
Did you know that Tesla created the equivalent of a waterwheel that tapped the energy of Earth's motion through the coelestial aether? Unfortunately, the resulting drag force was larger than he'd predicted, and after his experiments introduced a full extra day in 1893 (February 31, 1893 - google it), he was forced to stop his experiments. The original wheel is still on display in his home town of Smiljan. On special occasions, it is started up and let spin freely, without a load attached. To fix the mess he made, Tesla had to use the energy he'd stored up from the wheel (in a huge bank of capacitors - creating this was such a feat that the unit for capacitance is now named in his honor) to actually drive the wheel and restore the Earth's proper rotational period. Of course, the transfer wasn't without loss, which is why years divisible by 100 do not have leap days any longer.

learc83 15y ago

From the video it looked like there was still some airflow in the reverse direction.

blahedo 15y ago
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.
- backprojection 15y ago
  Looks like the shape tries to maximize turbulence in one direction, and minimize it in the other. Probably it would be an effective mixing device too.
  - imperator 15y ago
    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.

damoncali 15y ago

From the comments: Reminds me of http://en.wikipedia.org/wiki/Vortex_tube http://en.wikipedia.org/wiki/Vortex_tube Another simple yet fascinating device

imperator 15y ago
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.

mikeknoop 15y ago

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?

imperator 15y ago
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.

georgieporgie 15y ago

If you haven't read Tesla's autobiography[1], I highly recommend it. http://www.tfcbooks.com/special/my_inventions_index.htm http://www.tfcbooks.com/special/my_inventions_index.htm [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.

acqq 15y ago
It is a collection of articles for the "Electrical Experimenter" magazine: http://en.wikipedia.org/wiki/Electrical_Experimenter http://en.wikipedia.org/wiki/Electrical_Experimenter The articles were written by Tesla and they are autobiographical. 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.

stretchwithme 15y ago

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.

imperator 15y ago
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-microvalve/ http://www.senlin41.org/topology-optimization-of-tesla-type-...
- stretchwithme 15y ago
  nice. thanks!

imperator 15y ago

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.

recusancy 15y ago
You should do an AMA on reddit.
- imperator 15y ago
  Someone did a TIL on reddit and I popped in to answer questions there, too. http://www.reddit.com/r/todayilearned/comments/obyxj/til_that_nicola_tesla_invented_a_valve_that_lets/ http://www.reddit.com/r/todayilearned/comments/obyxj/til_tha...
apu 15y ago
I'm currently inventing a jet engine with no moving parts A ramjet?
- imperator 15y ago
  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 http://aardvark.co.nz/pjet/valveless.htm The Gluhareff Pressure jet is also a neat example. https://en.wikipedia.org/wiki/Gluhareff_Pressure_Jet https://en.wikipedia.org/wiki/Gluhareff_Pressure_Jet
  - sbierwagen 15y ago
    A pulsejet based on the Tesla valve? So, like that prototype Bruce Simpson was talking about ten years ago? https://webcache.googleusercontent.com/search?q=cache:UX5eNgncG3MJ:aardvark.co.nz/pjet/xjet.shtml+&cd=1&hl=en&ct=clnk&gl=us&client=firefox-a https://webcache.googleusercontent.com/search?q=cache:UX5eNg...

Tycho 15y ago

Can someone post a link to the desktop version? Site is unreadable on iPad.

mdonahoe 15y ago
Scroll down and turn off The mobile version of the Wordpress theme.

meric 15y ago

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.

imperator 15y ago
If you are still waiting for that day, you can get the valve 3D printed now from my shop: http://www.shapeways.com/model/292339/tesla_valve.html http://www.shapeways.com/model/292339/tesla_valve.html And if you already have a 3D printer, you can get the files free here: http://www.thingiverse.com/thing:16919 http://www.thingiverse.com/thing:16919

o2sd 15y ago

I remember reading about this valve in 'Man Out Of Time'[1], (great book BTW, highly recommended). Well, you said ask questions. :) 1) I seem to recall this valve only works when there is flow, so if you need to store liquid oxygen, for example, you would still need a check valve on the tank. Is that correct? 2) I think there is another variation on this valve for liquids, is that right? This version is for gasses, the valve for liquids looks like a series of petals. Is that right or did I imagine it? 3) Was the original intent of this valve to prevent back pressure from the blade turbine? Thanks, o2sd [1] http://www.bookdepository.com/Tesla-Man-out-Time-Margaret-Cheney/9780743215367 http://www.bookdepository.com/Tesla-Man-out-Time-Margaret-Ch...

imperator 15y ago
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-microvalve/ 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.

thusly 15y ago

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."

salemh 15y ago
His own biography (somewhat stilted writing, the constant "I" self-referrals, but, dense and very interesting): My Inventions: The Autobiography of Nikola Tesla http://www.amazon.com/My-Inventions-Autobiography-Nikola-Tesla/dp/0910077002/ref=sr_1_1?s=books&ie=UTF8&qid=1328411812&sr=1-1 http://www.amazon.com/My-Inventions-Autobiography-Nikola-Tes... 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.
bane 15y ago
My late-night reading currently consists of the book "Wizard: The Life and Times of Nikola Tesla I'd recommend "The Prestige" http://www.imdb.com/title/tt0482571/ http://www.imdb.com/title/tt0482571/ which has a fascinating portrayal of Tesla as a kind of mad techno Wizard (played by David Bowie of all people).
- thret 15y ago
  The Prestige is complete fiction that merely uses his name because he is recognisable as a practical genius.

rbanffy 15y ago

Does it work with incompressible fluids? Can someone test one with water?

imperator 15y ago
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.

kragen 15y ago

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/000706.html 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=PA118&lpg=PA118&dq=taught+air+to+think+fluidics&source=bl&ots=Qt70QlAjgX&sig=axEWaqYpR8KHH76sJ4LOfIRTDoI&hl=es-419&sa=X&ei=evQtT861JomDtge7qoWNBg&ved=0CCYQ6AEwAA#v=onepage&q&f=false 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 http://en.wikipedia.org/wiki/Fluidics

gjm11 15y ago
See also: http://catb.org/jargon/html/G/glitch.html#crunchly73-06-04 http://catb.org/jargon/html/G/glitch.html#crunchly73-06-04 and follow the next-cartoon chain from there. I particularly like http://catb.org/jargon/html/N/number-crunching.html#crunchly74-12-25 http://catb.org/jargon/html/N/number-crunching.html#crunchly... .

mrstinton 15y ago

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.

imperator 15y ago
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.
gcb 15y ago
a patent is a record of the working device, not the process used to get to it. thinking of anyone as a supernatural genius is nonsense. most of the time.
- jacquesm 15y ago
  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.