4 ms·

Here's the best resource that I know of for building ion wind "lifters": http://jnaudin.free.fr/lifters/main.htm http://jnaudin.free.fr/lifters/main.htm So fa

Here's the best resource that I know of for building ion wind "lifters": http://jnaudin.free.fr/lifters/main.htm http://jnaudin.free.fr/lifters/main.htm So far their best result is 0.886 kW/kg (0.539 hp/lb), comparable to a helicopter, by using a pulsed DC power supply at 70 Hz: http://jnaudin.free.fr/html/lftphv.htm http://jnaudin.free.fr/html/lftphv.htm So a helicopter with that could lift 1.13 kg/kW (1.86 lb/hp). A plane with a 10:1 lift to drag ratio would fly with 0.0886 kW/Kg (0.0539 hp/lb). It could lift 11.3 kg/kW (18.6 lb/hp). A 200 kg (440 lb) helicopter, including human passenger, would take 177 kW (237 hp). The same mass airplane would take 17.7 kW (23.7 hp). Of course the pulsing would add a buzz which may not be desirable. It looks like the pulsed DC uses 17.72 RMS W vs 69.58 DC W, so is about 3.927 times more efficient than DC. Maybe a plane could have both silent and high efficiency modes for takeoff and cruising. I have no idea how these numbers compare to the ones in the article, but they should be within the same magnitude. Please someone double check my math :-)

ColanR 8y ago
When I was young and foolish, I remember running into that same website through UFO conspiracy theory sites. Theory was/is, the ion wind 'lifter' tech was figured out many decades ago and that's how those pesky flying saucers get around.
- lightedman 8y ago
  Well, kinda, yea. About 25 years ago we had confidential demos from a company I worked for where we made substantially heavier (compared to now) solar cells literally float in the air using self-generated ionic thrust. Problem was, that was all the power you could get, and even then it wasn't enough to keep the cell afloat. Back then, we were using 10%-ish efficiency cells. Where I work now, we just toss 21+% monocrystalline cells which are 1/8th the mass of the originals around and don't care if they break, because as long as you can still put a bus ribbon on them all the way, they will produce full rated power, even if it looks like they were nailed with a sawed-off shotgun on the EL image. “You want to play with 40,000 volts on an aircraft? That technology didn’t exist. Steve [Barrett] found a clever way to get that efficient conversion.” So, the technology existed (when you do PWM with DC it mostly acts like AC so you can run it through a basic transformer) but they figured out the circuitry to make it efficient (nevermind solar efficiency now is enough to do what we want today without the basic transformer tech from almost 20 years ago.) Still neat, but this really hints of amateurs that never checked some basic math which hinted at this possibility, and existed back in the 70s, which was before I was even born. EDIT: added the second half after re-reading, edited again to make the PWM DC statement more clear.
- ColanR 8y ago
  Why is the comment by lightedman dead?
  - grzm 8y ago
    Likely because at some point 'lightedman was banned. If you feel the comment is worthy, you can vouch for it by clicking the timestamp of the comment and clicking "vouch".
gibolt 8y ago
Would be great to have some comparisons for energy requirements to other common appliances or surface area/weight percentage required to propel each configuration.
mrfusion 8y ago
In your link he mentions not being able to test higher frequencies but Says “Ithink that the Lifter efficiency can be greatly increased and even overcome the efficiency of a conventional helicopter with better flight characteristics.”
phs318u 8y ago
While the lifter clearly represents a manifestation of some reall effect, they do themselves no favours by linking to a book called "Secrets of Antigravity Propulsion" that claims to expose the secrets covered-up by NASA with respect to the B2's "highly secret electrogravitic field propulsion system" and Rocketdyne's secret antigravity propulsion project. I hate the fact that phenomena worthy of proper scientific examination are often also massive nut-job magnets.
- tonic-music 8y ago
  You can see why... Actual geniuses are attracted to the hard problems and are usually called massive nut jobs at first.
- Natanael_L 8y ago
  https://www.researchgate.net/publication/316438315_Gravitational-magnetic-electric_fields_interaction_vi https://www.researchgate.net/publication/316438315_Gravitati... Seems to be possible in theory, but appears to require pretty extreme energies
lokopodium 8y ago
Something doesn't quite add up. Cessna 172 and Robinson R44 use similarly powered engines for similar payload, same on the the heavy end of transport planes vs transport choppers.
- zackmorris 8y ago
  You bring up a good point. There are a few things going on here: https://en.wikipedia.org/wiki/Aspect_ratio_(aeronautics) https://en.wikipedia.org/wiki/Aspect_ratio_(aeronautics) https://en.wikipedia.org/wiki/Lift-to-drag_ratio#Theory https://en.wikipedia.org/wiki/Lift-to-drag_ratio#Theory https://en.wikipedia.org/wiki/Helicopter_rotor#Overview https://en.wikipedia.org/wiki/Helicopter_rotor#Overview In general, the lift to drag ratio (L/D) of an airfoil is proportional to the square root of the aspect ratio (AR). For airplane wings, this hits a limit of about 60 simply due to the difficulty of reinforcing a long wing while keeping weight down. A helicopter rotor spins, so has different requirements (like greater strength near the hub) so can have a higher aspect ratio. Unfortunately the inner third of the rotor turns too slowly to contribute much lift, and the tips shed large toroidal vortices that diminish efficiency. The tips also encounter turbulence near the speed of sound which diminishes efficiency. So rotors (even on wind turbines) can't really get higher than 60% efficiency: https://en.wikipedia.org/wiki/Betz%27s_law#Betz's_law_and_coefficient_of_performance https://en.wikipedia.org/wiki/Betz%27s_law#Betz's_law_and_co... There has probably been more research in helicopter rotors over the years than increasing the L/D ratio of light aircraft, which explains how they reduced some of the discrepancy between the two. When I was doing research for the Sikorsky human powered helicopter competition (unfortunately someone already won it haha), I did a lot of napkin calculations for this sort of thing: https://en.wikipedia.org/wiki/Igor_I._Sikorsky_Human_Powered_Helicopter_Competition https://en.wikipedia.org/wiki/Igor_I._Sikorsky_Human_Powered... Success came down to having the fewest, longest, thinnest, lightest rotor blades possible: http://www.pitt.edu/~jdnorton/Goodies/TE-antiTE/ http://www.pitt.edu/~jdnorton/Goodies/TE-antiTE/ There are many ways of increasing lift using winglets, vortex generators, EHD devices, etc (a few other keywords to look for are boundary layer and Reynolds number): https://en.wikipedia.org/wiki/Wingtip_device https://en.wikipedia.org/wiki/Wingtip_device https://en.wikipedia.org/wiki/Vortex_generator https://en.wikipedia.org/wiki/Vortex_generator https://sbir.gsfc.nasa.gov/content/aerodynamic-efficiency-drag-reduction-technology-0 https://sbir.gsfc.nasa.gov/content/aerodynamic-efficiency-dr... Personally I don't think we've even scratched the surface of what's possible in L/D ratios. With modern materials science and computer simulation at our disposal, I'd like to see someone break 100. Probably by using an array of airfoils and some EHD effects. I don't think anyone is seriously looking at it though other than maybe Bigelow Aerospace (JP Aerospace) and their defunct airships-to-orbit project: https://rimstar.org/space/jp_aerospace_balloon_airship_to_orbit.htm https://rimstar.org/space/jp_aerospace_balloon_airship_to_or... https://en.wikipedia.org/wiki/JP_Aerospace https://en.wikipedia.org/wiki/JP_Aerospace https://en.wikipedia.org/wiki/Bigelow_Aerospace https://en.wikipedia.org/wiki/Bigelow_Aerospace I think this idea has merit and is one of the only ones that can compete on price with a space elevator. But it's not sexy enough, and people are still stuck on the idea of using helium instead of hydrogen, which sabotages it from ever succeeding (due to the limited supply of helium). I would love to work on revolutionary ideas like this, but like most of you, I'm building SPA CRUD apps on the web to pay the mortgage. Sorry there's a lot of info here, but hey it's black friday on HN. What else are we gonna do.
Gravityloss 8y ago
Naudin has flown lifters as well as ion wind propelled flying wings for a long time. Not maybe 100% sure if all had either wires to ground or other propulsors as well. But the "world first" seems like a great exaggeration. (Edited for tone)

ColanR 8y ago

When I was young and foolish, I remember running into that same website through UFO conspiracy theory sites. Theory was/is, the ion wind 'lifter' tech was figured out many decades ago and that's how those pesky flying saucers get around.

lightedman 8y ago
Well, kinda, yea. About 25 years ago we had confidential demos from a company I worked for where we made substantially heavier (compared to now) solar cells literally float in the air using self-generated ionic thrust. Problem was, that was all the power you could get, and even then it wasn't enough to keep the cell afloat. Back then, we were using 10%-ish efficiency cells. Where I work now, we just toss 21+% monocrystalline cells which are 1/8th the mass of the originals around and don't care if they break, because as long as you can still put a bus ribbon on them all the way, they will produce full rated power, even if it looks like they were nailed with a sawed-off shotgun on the EL image. “You want to play with 40,000 volts on an aircraft? That technology didn’t exist. Steve [Barrett] found a clever way to get that efficient conversion.” So, the technology existed (when you do PWM with DC it mostly acts like AC so you can run it through a basic transformer) but they figured out the circuitry to make it efficient (nevermind solar efficiency now is enough to do what we want today without the basic transformer tech from almost 20 years ago.) Still neat, but this really hints of amateurs that never checked some basic math which hinted at this possibility, and existed back in the 70s, which was before I was even born. EDIT: added the second half after re-reading, edited again to make the PWM DC statement more clear.
ColanR 8y ago
Why is the comment by lightedman dead?
- grzm 8y ago
  Likely because at some point 'lightedman was banned. If you feel the comment is worthy, you can vouch for it by clicking the timestamp of the comment and clicking "vouch".

gibolt 8y ago

Would be great to have some comparisons for energy requirements to other common appliances or surface area/weight percentage required to propel each configuration.

mrfusion 8y ago

In your link he mentions not being able to test higher frequencies but Says “Ithink that the Lifter efficiency can be greatly increased and even overcome the efficiency of a conventional helicopter with better flight characteristics.”

phs318u 8y ago

While the lifter clearly represents a manifestation of some reall effect, they do themselves no favours by linking to a book called "Secrets of Antigravity Propulsion" that claims to expose the secrets covered-up by NASA with respect to the B2's "highly secret electrogravitic field propulsion system" and Rocketdyne's secret antigravity propulsion project. I hate the fact that phenomena worthy of proper scientific examination are often also massive nut-job magnets.

tonic-music 8y ago
You can see why... Actual geniuses are attracted to the hard problems and are usually called massive nut jobs at first.
Natanael_L 8y ago
https://www.researchgate.net/publication/316438315_Gravitational-magnetic-electric_fields_interaction_vi https://www.researchgate.net/publication/316438315_Gravitati... Seems to be possible in theory, but appears to require pretty extreme energies

lokopodium 8y ago

Something doesn't quite add up. Cessna 172 and Robinson R44 use similarly powered engines for similar payload, same on the the heavy end of transport planes vs transport choppers.

zackmorris 8y ago
You bring up a good point. There are a few things going on here: https://en.wikipedia.org/wiki/Aspect_ratio_(aeronautics) https://en.wikipedia.org/wiki/Aspect_ratio_(aeronautics) https://en.wikipedia.org/wiki/Lift-to-drag_ratio#Theory https://en.wikipedia.org/wiki/Lift-to-drag_ratio#Theory https://en.wikipedia.org/wiki/Helicopter_rotor#Overview https://en.wikipedia.org/wiki/Helicopter_rotor#Overview In general, the lift to drag ratio (L/D) of an airfoil is proportional to the square root of the aspect ratio (AR). For airplane wings, this hits a limit of about 60 simply due to the difficulty of reinforcing a long wing while keeping weight down. A helicopter rotor spins, so has different requirements (like greater strength near the hub) so can have a higher aspect ratio. Unfortunately the inner third of the rotor turns too slowly to contribute much lift, and the tips shed large toroidal vortices that diminish efficiency. The tips also encounter turbulence near the speed of sound which diminishes efficiency. So rotors (even on wind turbines) can't really get higher than 60% efficiency: https://en.wikipedia.org/wiki/Betz%27s_law#Betz's_law_and_coefficient_of_performance https://en.wikipedia.org/wiki/Betz%27s_law#Betz's_law_and_co... There has probably been more research in helicopter rotors over the years than increasing the L/D ratio of light aircraft, which explains how they reduced some of the discrepancy between the two. When I was doing research for the Sikorsky human powered helicopter competition (unfortunately someone already won it haha), I did a lot of napkin calculations for this sort of thing: https://en.wikipedia.org/wiki/Igor_I._Sikorsky_Human_Powered_Helicopter_Competition https://en.wikipedia.org/wiki/Igor_I._Sikorsky_Human_Powered... Success came down to having the fewest, longest, thinnest, lightest rotor blades possible: http://www.pitt.edu/~jdnorton/Goodies/TE-antiTE/ http://www.pitt.edu/~jdnorton/Goodies/TE-antiTE/ There are many ways of increasing lift using winglets, vortex generators, EHD devices, etc (a few other keywords to look for are boundary layer and Reynolds number): https://en.wikipedia.org/wiki/Wingtip_device https://en.wikipedia.org/wiki/Wingtip_device https://en.wikipedia.org/wiki/Vortex_generator https://en.wikipedia.org/wiki/Vortex_generator https://sbir.gsfc.nasa.gov/content/aerodynamic-efficiency-drag-reduction-technology-0 https://sbir.gsfc.nasa.gov/content/aerodynamic-efficiency-dr... Personally I don't think we've even scratched the surface of what's possible in L/D ratios. With modern materials science and computer simulation at our disposal, I'd like to see someone break 100. Probably by using an array of airfoils and some EHD effects. I don't think anyone is seriously looking at it though other than maybe Bigelow Aerospace (JP Aerospace) and their defunct airships-to-orbit project: https://rimstar.org/space/jp_aerospace_balloon_airship_to_orbit.htm https://rimstar.org/space/jp_aerospace_balloon_airship_to_or... https://en.wikipedia.org/wiki/JP_Aerospace https://en.wikipedia.org/wiki/JP_Aerospace https://en.wikipedia.org/wiki/Bigelow_Aerospace https://en.wikipedia.org/wiki/Bigelow_Aerospace I think this idea has merit and is one of the only ones that can compete on price with a space elevator. But it's not sexy enough, and people are still stuck on the idea of using helium instead of hydrogen, which sabotages it from ever succeeding (due to the limited supply of helium). I would love to work on revolutionary ideas like this, but like most of you, I'm building SPA CRUD apps on the web to pay the mortgage. Sorry there's a lot of info here, but hey it's black friday on HN. What else are we gonna do.

Gravityloss 8y ago

Naudin has flown lifters as well as ion wind propelled flying wings for a long time. Not maybe 100% sure if all had either wires to ground or other propulsors as well. But the "world first" seems like a great exaggeration. (Edited for tone)