7 ms·

Tesla valve

100 points by Jeff_Brown 5y ago

osamagirl69 5y ago
There is an youtube video[1] by the excellent channel Huygens Optics which goes through trying to make a microscopic tesla valve. The valve does not work as a checkvalve (it is sufficiently small that surface tension and all that work differently than in a macroscopic system), but the author argues that it did satisfy the real goal of being a tesla valve -- which is to look sexy and high tech. [1]https://www.youtube.com/watch?v=gQnmP7UD_zk https://www.youtube.com/watch?v=gQnmP7UD_zk
b3q5h 5y ago
Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot!
amelius 5y ago
> One computational fluid dynamics simulation of Tesla valves with two and four segments showed that the flow resistance in the blocking (or reverse) direction was about 15 and 40 times greater, respectively, than the unimpeded (or forward) direction. > Steady flow experiments, including with the original design, however, show smaller ratios of the two resistances in the range of 2 to 4. So the simulations are off by a factor of 10? How is this possible?
- SuoDuanDao 5y ago
  Just guessing, but I think water is more compressible than how it's commonly modelled.
  - bernulli 5y ago
    It's really not for almost all encounters we will ever have with it. In fact, you can model even air (or other gases) as incompressible as long as the Mach number is <0.3 with really good accuracy.
- dagw 5y ago
  So the simulations are off by a factor of 10? How is this possible? It's hard to say since there is zero information about how the simulation they mentioned was done in the footnoted article. Most likely they either screwed up the mesh or the, more likely, the turbulence modelling. It's hard to say why the Wikipedia author chose that particular article/simulation results, since the article presenting the results is very superficial. If you look at results from other simulations you can find numbers between 1.5-7 depending on the exact simulation setup. If you read the paper linked to in the footnote to the steady flow experiment you'll see that the results are very dependent on the turbulence and Reynolds number of the liquid so how you feed the liquid into the valve (how fast and how steady) can greatly impact your results. So if the simulation and the experiment used different pressures for the water entering the system, just that could explain some of the discrepancy.
  - markenqualitaet 5y ago
    You seem to know a thing or two. Could you point me to an intro for material/physics simulation? Keywords and such? Some basic ideas or even tutorials how this is approached and the common pitfalls? Is water simulated like gas, sand, or spaghetti? Are internal grid configuration and electromagnetic properties considered usually? Water's chemistry and physics makes it such a special thing, no? What's the scale when things commonly fall apart? Is quantum computation a possible answer to scalability? Can you "divide and conquer" a fluid system? Do real life model measurements tell you much about upscaled applications? I only know people hate fluid dynamics studying physics and that it's a hard problem.
SimianLogic2 5y ago
I tried to carve one of these in styrofoam just to show it to the kids after reading about it a year or so ago, but the material was too soft/porous. It's on my project TODO list if I can ever talk the wife into letting me buy a 3d printer or glowforge.
- spockz 5y ago
  Maybe you can coat the styrofoam with paint or glue? Or cut it from wood?
  - deleted 5y ago
    [deleted]
  - iamgopal 5y ago
    Yes, or even plastic and glue or acrylic, or even lego, anything has better chance than convincing wife. ;)
- all2 5y ago
  Forgiveness, not permission. :)
  - SimianLogic2 5y ago
    Haha, cash isn't the limiting factor -- it's the hours of disappearing into the workshop to leave her with childcare duties. I just need to wait for the kids to get a bit older and I can make it a team activity.
    - all2 5y ago
      Yeah. Cherish that time, tho. Kiddos grow up so fast.
showerst 5y ago
For a fun visual demonstration, check out nighthawkinlight's video where he runs a flamefront through one -- https://www.youtube.com/watch?v=tcV1EYSUQME https://www.youtube.com/watch?v=tcV1EYSUQME Also seconding the Huygen's optics video osamagirl69 already posted below -- https://www.youtube.com/watch?v=gQnmP7UD_zk https://www.youtube.com/watch?v=gQnmP7UD_zk
tablespoon 5y ago
Tesla was quite the polymath.
leifg 5y ago
Was I the only one who assumed it's gonna be some new Tesla (the company) product?
dr_orpheus 5y ago
> Steady flow experiments, including with the original design, however, show smaller ratios of the two resistances in the range of 2 to 4. I looked at the linked article [0] for this statement and I was hoping to see other passive check valve designs. But it mostly looked like the original Tesla design. Have there been optimizations of the design that achieve a better performance since the original Tesla design? [0] https://www.nature.com/articles/s41467-021-23009-y https://www.nature.com/articles/s41467-021-23009-y
markenqualitaet 5y ago
Does anyone know, if there is research into hygenic aspects of Tesla valves compared to traditional ones? Like biofilm formation experiments? I was yesterday wondering, if it would make sense to include these into household water piping to ensure mono directional flow, preventing contamination from dirty ends. Doesn't my faucet current create suction on the washing machine's connection? Then again a Tesla valve may be a bio-safespace itself, as there are probably pro-life areas around the turbulences, different water exchange rates and maybe even different gas (oxygen) concentrations. Also why isn't the cold water line used to dehumidify the shower? I assume my "smart" ideas about water infrastructure would mostly get me killed by legionella at some point. Excessive regulation on touching the water probably isn't just for killing the fun and creating jobs... (I recently learned all water pipes are covered in biofilm after 2-3 years, even tho there is hardly any bacteria cell in my country's water. So, there seems to be a disgusting and probably fragile ecosystem to consider...)
- coryrc 5y ago
  > Doesn't my faucet current create suction on the washing machine's connection? Even if it did, it doesn't create any flow, which would be necessary for the valve to function.
  - markenqualitaet 5y ago
    Probably a good point. I think I am making the tesla valve more than it is. I am prone to this. Thanks.
- rsync 5y ago
  I don't know how "leaky" a tesla valve is and if that leakiness (if it's non-zero) matters to the (pulsejet ? microfluids ?) applications it is used in. Generally speaking, any volume of household/utility water is considered sewage if even one drop of sewage enters it. In California, utility connections utilize double-check valves with inspection ports that allow an inspector to regularly check the expected pressure drop between the two check valves and ensure they are not leaking.[1][2] I don't know if that is more, or less, aggressive than a Tesla valve with (for instance) 8 or 10 "segments". [1] https://en.wikipedia.org/wiki/Double_check_valve https://en.wikipedia.org/wiki/Double_check_valve [2] https://www.mscdirect.com/product/details/65889354 https://www.mscdirect.com/product/details/65889354
omrjml 5y ago
Modern use for it: https://www.newscientist.com/article/2277794-century-old-water-valve-invented-by-nikola-tesla-could-have-modern-use/ https://www.newscientist.com/article/2277794-century-old-wat...
- Jeff_Brown 5y ago
  Outstanding. That's the closest thing to free power I've seen.
vital303 5y ago
An interactive simulation of Tesla valve. https://tinyurl.com/yzcr74gw https://tinyurl.com/yzcr74gw
QuadmasterXLII 5y ago
If you were looking for a litmus test to distinguish armchair engineers and cranks from people who build things that work, you could do worse than "How important to the future of engineering is the tesla valve?"
rajnathani 5y ago
Recent discussion (2021 May / 223 points / 64 comments): https://news.ycombinator.com/item?id=27215894 https://news.ycombinator.com/item?id=27215894

100 points by Jeff_Brown 5y ago

There is an youtube video[1] by the excellent channel Huygens Optics which goes through trying to make a microscopic tesla valve. The valve does not work as a checkvalve (it is sufficiently small that surface tension and all that work differently than in a macroscopic system), but the author argues that it did satisfy the real goal of being a tesla valve -- which is to look sexy and high tech. [1]https://www.youtube.com/watch?v=gQnmP7UD_zk https://www.youtube.com/watch?v=gQnmP7UD_zk

b3q5h 5y ago

Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot! Vax passport supporters are NAZIS and they must be shot!

amelius 5y ago

> One computational fluid dynamics simulation of Tesla valves with two and four segments showed that the flow resistance in the blocking (or reverse) direction was about 15 and 40 times greater, respectively, than the unimpeded (or forward) direction. > Steady flow experiments, including with the original design, however, show smaller ratios of the two resistances in the range of 2 to 4. So the simulations are off by a factor of 10? How is this possible?

SuoDuanDao 5y ago
Just guessing, but I think water is more compressible than how it's commonly modelled.
- bernulli 5y ago
  It's really not for almost all encounters we will ever have with it. In fact, you can model even air (or other gases) as incompressible as long as the Mach number is <0.3 with really good accuracy.
dagw 5y ago
So the simulations are off by a factor of 10? How is this possible? It's hard to say since there is zero information about how the simulation they mentioned was done in the footnoted article. Most likely they either screwed up the mesh or the, more likely, the turbulence modelling. It's hard to say why the Wikipedia author chose that particular article/simulation results, since the article presenting the results is very superficial. If you look at results from other simulations you can find numbers between 1.5-7 depending on the exact simulation setup. If you read the paper linked to in the footnote to the steady flow experiment you'll see that the results are very dependent on the turbulence and Reynolds number of the liquid so how you feed the liquid into the valve (how fast and how steady) can greatly impact your results. So if the simulation and the experiment used different pressures for the water entering the system, just that could explain some of the discrepancy.
- markenqualitaet 5y ago
  You seem to know a thing or two. Could you point me to an intro for material/physics simulation? Keywords and such? Some basic ideas or even tutorials how this is approached and the common pitfalls? Is water simulated like gas, sand, or spaghetti? Are internal grid configuration and electromagnetic properties considered usually? Water's chemistry and physics makes it such a special thing, no? What's the scale when things commonly fall apart? Is quantum computation a possible answer to scalability? Can you "divide and conquer" a fluid system? Do real life model measurements tell you much about upscaled applications? I only know people hate fluid dynamics studying physics and that it's a hard problem.

SimianLogic2 5y ago

I tried to carve one of these in styrofoam just to show it to the kids after reading about it a year or so ago, but the material was too soft/porous. It's on my project TODO list if I can ever talk the wife into letting me buy a 3d printer or glowforge.

spockz 5y ago
Maybe you can coat the styrofoam with paint or glue? Or cut it from wood?
- deleted 5y ago
  [deleted]
- iamgopal 5y ago
  Yes, or even plastic and glue or acrylic, or even lego, anything has better chance than convincing wife. ;)
all2 5y ago
Forgiveness, not permission. :)
- SimianLogic2 5y ago
  Haha, cash isn't the limiting factor -- it's the hours of disappearing into the workshop to leave her with childcare duties. I just need to wait for the kids to get a bit older and I can make it a team activity.
  - all2 5y ago
    Yeah. Cherish that time, tho. Kiddos grow up so fast.

showerst 5y ago

For a fun visual demonstration, check out nighthawkinlight's video where he runs a flamefront through one -- https://www.youtube.com/watch?v=tcV1EYSUQME https://www.youtube.com/watch?v=tcV1EYSUQME Also seconding the Huygen's optics video osamagirl69 already posted below -- https://www.youtube.com/watch?v=gQnmP7UD_zk https://www.youtube.com/watch?v=gQnmP7UD_zk

tablespoon 5y ago

Tesla was quite the polymath.

leifg 5y ago

Was I the only one who assumed it's gonna be some new Tesla (the company) product?

dr_orpheus 5y ago

> Steady flow experiments, including with the original design, however, show smaller ratios of the two resistances in the range of 2 to 4. I looked at the linked article [0] for this statement and I was hoping to see other passive check valve designs. But it mostly looked like the original Tesla design. Have there been optimizations of the design that achieve a better performance since the original Tesla design? [0] https://www.nature.com/articles/s41467-021-23009-y https://www.nature.com/articles/s41467-021-23009-y

markenqualitaet 5y ago

Does anyone know, if there is research into hygenic aspects of Tesla valves compared to traditional ones? Like biofilm formation experiments? I was yesterday wondering, if it would make sense to include these into household water piping to ensure mono directional flow, preventing contamination from dirty ends. Doesn't my faucet current create suction on the washing machine's connection? Then again a Tesla valve may be a bio-safespace itself, as there are probably pro-life areas around the turbulences, different water exchange rates and maybe even different gas (oxygen) concentrations. Also why isn't the cold water line used to dehumidify the shower? I assume my "smart" ideas about water infrastructure would mostly get me killed by legionella at some point. Excessive regulation on touching the water probably isn't just for killing the fun and creating jobs... (I recently learned all water pipes are covered in biofilm after 2-3 years, even tho there is hardly any bacteria cell in my country's water. So, there seems to be a disgusting and probably fragile ecosystem to consider...)

coryrc 5y ago
> Doesn't my faucet current create suction on the washing machine's connection? Even if it did, it doesn't create any flow, which would be necessary for the valve to function.
- markenqualitaet 5y ago
  Probably a good point. I think I am making the tesla valve more than it is. I am prone to this. Thanks.
rsync 5y ago
I don't know how "leaky" a tesla valve is and if that leakiness (if it's non-zero) matters to the (pulsejet ? microfluids ?) applications it is used in. Generally speaking, any volume of household/utility water is considered sewage if even one drop of sewage enters it. In California, utility connections utilize double-check valves with inspection ports that allow an inspector to regularly check the expected pressure drop between the two check valves and ensure they are not leaking.[1][2] I don't know if that is more, or less, aggressive than a Tesla valve with (for instance) 8 or 10 "segments". [1] https://en.wikipedia.org/wiki/Double_check_valve https://en.wikipedia.org/wiki/Double_check_valve [2] https://www.mscdirect.com/product/details/65889354 https://www.mscdirect.com/product/details/65889354

omrjml 5y ago

Modern use for it: https://www.newscientist.com/article/2277794-century-old-water-valve-invented-by-nikola-tesla-could-have-modern-use/ https://www.newscientist.com/article/2277794-century-old-wat...

Jeff_Brown 5y ago
Outstanding. That's the closest thing to free power I've seen.

vital303 5y ago

An interactive simulation of Tesla valve. https://tinyurl.com/yzcr74gw https://tinyurl.com/yzcr74gw

QuadmasterXLII 5y ago

If you were looking for a litmus test to distinguish armchair engineers and cranks from people who build things that work, you could do worse than "How important to the future of engineering is the tesla valve?"

rajnathani 5y ago

Recent discussion (2021 May / 223 points / 64 comments): https://news.ycombinator.com/item?id=27215894 https://news.ycombinator.com/item?id=27215894