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Silent and Simple Ion Engine Powers a Plane with No Moving Parts

662 points| tshannon | 7 years ago |scientificamerican.com | reply

223 comments

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[+] zackmorris|7 years ago|reply
Here's the best resource that I know of for building ion wind "lifters":

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

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 :-)

[+] phs318u|7 years ago|reply
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.

[+] ColanR|7 years ago|reply
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.
[+] Gravityloss|7 years ago|reply
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)

[+] mrfusion|7 years ago|reply
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.”
[+] lokopodium|7 years ago|reply
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.
[+] gibolt|7 years ago|reply
Would be great to have some comparisons for energy requirements to other common appliances or surface area/weight percentage required to propel each configuration.
[+] _Microft|7 years ago|reply
Ars Technica has an article on this as well. It features a 5 minute video of various attempts and sustained flight as well.

https://arstechnica.com/science/2018/11/small-drone-soars-on...

[+] taneq|7 years ago|reply
Thanks! I wonder why TFA didn't show any photos? It always makes me skeptical when a news story about a new design is accompanied only by renders.
[+] teekert|7 years ago|reply
Hero! First thing I look for is videos in the article, then in the HN comments...
[+] mchannon|7 years ago|reply
As planes use most of their energy to not crash into the ground, I could see the most practical use of this technology for propulsion where crashing isn't a major concern.

Airships (dirigibles/blimps), and to a lesser extent, sea and land vehicles.

[+] schiffern|7 years ago|reply
>planes use most of their energy to not crash into the ground

Surprisingly, not by much!

To the first approximation an optimized plane will use 50% of its power during cruise generating lift ("not crashing into the ground"), and 50% of its power overcoming drag.[1] The tie is broken because planes expend extra more energy climbing than they save descending, and that's also part of "not crashing into the ground." :)

[1] http://www.withouthotair.com/cC/page_272.shtml

[+] godelski|7 years ago|reply
I wouldn't expect to see this on passenger aircraft anytime soon. They even had to build light weight high voltage converters. There's also a lot of safety things involved when you're dealing with tens of kV (which in a big craft we're talking at lease MV). BUT these things could be used for silent drones. Think more spy type drones, not predator type drones.
[+] jessriedel|7 years ago|reply
> As planes use most of their energy to not crash into the ground

Not disputing you, but do you have a quick argument for this? My understanding is that passenger planes fly at high altitudes because at lower altitudes (higher pressures) they would expend most of their energy pushing air out of the way.

[+] shostack|7 years ago|reply
The sooner we get back to the age of dirigibles the better.

Personally, I'm a little surprised we don't have them in the Bay Area. With our traffic and (mostly) year round nice weather, and great solar energy potential it seems like it could be a win.

But then again I don't know much about the technology or it's limitations.

[+] albertgoeswoof|7 years ago|reply
This engine will struggle at high altitudes because there’s less air molecules to ionise
[+] grondilu|7 years ago|reply
Aren't most planes capable of gliding well enough to land?
[+] isostatic|7 years ago|reply
> I could see the most practical use of this technology for propulsion where crashing isn't a major concern.

Missiles jumped to mind. That's their whole purpose.

[+] ohiovr|7 years ago|reply
Sounds like lifters. Would it produce a lot of ozone pollution?
[+] detritus|7 years ago|reply
That's exactly what I was just wondering and trying to read up on (I'm incredibly ignorant about this sort of thing)...

https://www.quora.com/How-is-air-ionized-and-what-does-that-...

"Air ionisation can cause the following: forming of ozone molecules

Ozone is produced naturally in the stratosphere when highly energetic solar radiation strikes molecules of oxygen (O2), and cause the two oxygen atoms to split apart in a process called photolysis. If a freed atom collides with another O2, it joins up, forming ozone(O3). Most of the ozone in the stratosphere is formed over the equatorial belt, where the level of solar radiation is greatest. The circulation in the atmosphere then transports it towards the pole . So, the amount of stratospheric ozone above a location on the Earth varies naturally with latitude, season, and from day-to-day."

[+] mabbo|7 years ago|reply
Ah, darn. I was wondering if this might be a new way to have better indoor air circulation with no moving parts. But filling my home with ozone doesn't sound like a good idea.
[+] soperj|7 years ago|reply
From the article: the front row conducts some 40,000 volts of electricity—166 times the voltage delivered to the average house, and enough energy to strip the electrons off ample nitrogen atoms hanging in the atmosphere. So doesn't seem like it.
[+] sametmax|7 years ago|reply
Pollution is contextual. If they are required to fly very high, wouldn't it add ozone to the earth uv shield ?
[+] perlgeek|7 years ago|reply
Also potentially nitrogen oxide?
[+] nraynaud|7 years ago|reply
I don’t think you can move a lot of air silently, the turbulent layer between the flow and the still air produces noise. This is only silent because of size. Maybe less noisy than a fan or prop, but not silent.
[+] onemoresoop|7 years ago|reply
corrent, but it would still be "silent-er"
[+] perlgeek|7 years ago|reply
> When that happens, the nitrogen atoms turn into positively charged ions.

Does that mean it produces nitrogen oxide as exhaust? If yes, how long does that live?

If such planes were to be scaled up, that could be a potential hazard to be aware of.

[+] rkagerer|7 years ago|reply
I gather this thing ionizes air to create a positively charged "working fluid" which accelerates away from the anode in a cone shaped pattern. The working fluid doesn't generate [much(?)] thrust directly, as it collides with the craft again at the cathode. But along the way some of the ions near the edge of the cone bump into and accelerate neutral air molecules, generating the [bulk of the(?)] thrust that propels the craft.

With a modified design, is it possible to accelerate the ionized air so fast that all of it vents out the exhaust (e.g. using magnets)? Would that result in higher efficiency / higher thrust? Are there already atmosphere-breathing engines that do this and what are they called?

[+] ArtifTh|7 years ago|reply
>Are there already atmosphere-breathing engines that do this and what are they called?

Generally this kind of engine is called Magnetohydrodynamic drive. I'm not sure about atmospheric engines, but according to wiki[1] there are prototypes that uses water as working fluid.

[1] https://en.wikipedia.org/wiki/Magnetohydrodynamic_drive

[+] ceriodamus|7 years ago|reply
This man probably got contacted by X amount of countries militaries already.

The idea of a totally silent tiny drone that can get real close is scary to think of.

[+] cmroanirgo|7 years ago|reply
> “It was very exciting,” Barrett says. “Then it crashed into the wall, which wasn’t ideal.”

Reading this reminded me of the two Wright brothers, who had similar issues, and similar people around them, not believing it would work.

Kudos. It sounds pretty amazing to me.

[+] pugworthy|7 years ago|reply
Others have pointed this out I think, but this kind of craft concept has been around for a while. Here is a 1964 Popular Mechanics article about the idea...

http://www.rexresearch.com/desev/desev.htm

Different approach to flying but it’s interesting how some of the described reactions are similar about the silence and no moving parts.

I remember reading this article when I was a kid in a stack of PMs in the early 70s.

[+] mgpetkov|7 years ago|reply
But what would happen if the electrodes become wet like flying in rain, fog and so on?
[+] ceejayoz|7 years ago|reply
Sounds like it'd be perfect for exploring Mars.
[+] kwhitefoot|7 years ago|reply
> Powers a Plane with No Moving Parts

Yet all the pictures are renderings, artist's impressions. So, do they have a working model or not? There are no links to any supporting documents; Scientific American used to be better than this, very disappointing.

[+] olgs|7 years ago|reply
I wonder if it is possible to use this technology to build a noiseless fan.
[+] rudolph9|7 years ago|reply
Could this technology be used to create a wind turbine with no moving parts? I have very little insight into how this would work but it intuitively seems applicable and would probably be way more useful.
[+] kgilpin|7 years ago|reply
Flapping wings are also silent. And articulated wings can perform complex maneuvering including hover and vertical takeoff and landing.

So is there any other advantage to ion propulsion besides quiet operation?