Guy Negre: The car than runs on...air!

[CFLarsen]

(CNN) - It sounds like an ordinary car. But it's not. In the South of France, inventor Guy Negre says he's developed a car that runs on air.

He says that no fuel is necessary to power the car that can travel at speeds close to 70-miles-per-hour. It's a whole lot of fresh air, driving an engine that Negre says is zero-polluting.
CNN (http://edition.cnn.com/2004/TECH/science/01/23/air.car/index.html)

Guy Negre's website. (http://www.aircaraccess.com/)
If not for the sun's heat, our atmosphere would freeze and fall to the ground as snow. The sun adds about 500 degrees of temperature to the air and all this heat is stored in air. When air is pushed into a tank, that is, compressed above atmospheric pressure, its internal energy (solar heat) becomes available for use as a piston-pushing or turbine-driving power.

O...K.

I can't find anywhere where he describes how he gets the air compressed.

[pupdog]

Does Negre describe how much compressed air is required for moving a vehicle of normal mass, considering friction losses, braking, and accessories (like heating and air conditioning)? All air compressors I see for sale require electricity or fossil fuels to operate. Although other energy sources could be used, could they be made portable and incorporated in a vehicle?

Negre seems to confuse temperature and heat. Does he discuss the temperature differentials necessary for a working engine?

[Peskanov]

I don't understand the link you put, it seems quite loony.
However, the invention is known here. The air car was expected to be distributed in Spain and France some time ago, and was widely announced.
The air car can be recharged two ways:
- With a home air compressor, using your electricity.
- In gas stations. I don't know if the plan is using exsisting air compressors (for pneumatics), or to use dedicated machinery instead.

I don't know it's current status. I like the concept, the only problem I see is the big size of the air tanks.

[Reginald]

Won't that start to freeze up as the air decompressses? Or will friction in the engine be enough to keep it warm? I know that my air brush bottles chill right down If I'm doing some long work.

[Peskanov]

Their idea is to use the cold air to cool the cabinet in summer.
That's one of the selling points of the car in Spain, as we have warm weather 3/4 of the year.

[Iamme]

How much energy is required to produce the air in the first place? Is there a net gain?

We have gone through this with environmentalists arguing with the ethanol plant developers. There were claims circulating that it took more power to produce ethanol, than what you would get out of it. I still don't know what the truth to this is.

[_Q_]

Originally posted by CFLarsen
I can't find anywhere where he describes how he gets the air compressed. He covers that here (http://www.aircaraccess.com/nealtank.htm). The following quote is just a sample to whet your appetite. Go to the actual page to enjoy the text and diagram in all their splendor.
The real trick is “Maxwell’s Demon,” which we have discovered is the Bernoulli Effect: air pressure can be converted into air velocity (jet drive), so that in the localized absence of pressure (low pressure zone inside tank) the high velocity jet can induce low pressure air (continuous source of solar energy) into the tank without wasting a lot of energy compressing it to get it in. Because of air’s internal energy (heat that is there before and after the air is compressed), the power needed to generate compressed air is uniquely unrelated to the power available from the compressed air thus created. This gives the appearance of perpetual motion, but is not; it is a heat-pumping process.

This information checks out mathematically, and the US Patent Office routinely grants patents to inventors of self-fueling air engines.I'll certainly sleep better tonight knowing that.

I agree with pupdog. In this guy's world, "heat" does all sorts of wonderful things, but "temperature" doesn't seem to get much attention. Oh, and I think it's a load of tripe, too.


_Q_

[espritch]

I don't know it's current status. I like the concept, the only problem I see is the big size of the air tanks.

Divers use compressed air. One thing you learn early on is that a tank of compressed air can be rather dangerous if it is corroded or the valve gets busted (think shrapnel).

[Peskanov]

CFLarsen, your link is NOT related to Guy Negre, or his company.
The owners of the page seems to be Scott Robertson and Terry Miller, and their company is unconnected to Guy Negre's invention (I think).

Information about Guy Negre's company:

http://www.theaircar.com

Problems of the company

http://www.wired.com/news/autotech/0,2554,60427,00.html

[Peskanov]

Espritch, here you have company's answer:

http://www.theaircar.com/faq.html


How do the air tanks work and are there any issues with their safety?
One of the most frequently asked questions regards the safety of the air tanks, which store 90m3 of air at 300 bars of pressure. Many people ask whether this system is dangerous in case of an accident, and whether there is an explosion risk involved. The answer is NO. Why? Because the tanks are the ones already used to carry liquefied gases on some urban buses, and therefore make use of the technology that is already used to move buses on natural gas. That means that the tanks are prepared and certified to carry an explosive product: methane gas.

In the case of an accident, with air tank breakage, there would be no explosion or shattering, now that the tanks are not metallic. Due to the fact that they are made of glass fibre the tanks would crack longitudinally, and the air would escape, causing a strong buzzing sound with no dangerous factor. It is clear that if this technology has been tested and prepared to carry an inflammable and explosive gas, it can also be used to carry air.

A final matter with reference to the air tanks, is the improvement that MDI contributed to the original structure. In order to avoid the so-called 'rocket effect', this means to avoid the air escaping through one of the tank's extremities causing a pressure leak that could move the car, MDI made a small but important change in the design. The valve on the buses' tanks are placed on one of the extremities. MDI has placed the valve in the middle of the tank reducing the 'rocket effect' to a minimum.


Seem reasonable to me...

[Peskanov]

Lamme,


How much energy is required to produce the air in the first place? Is there a net gain?

We have gone through this with environmentalists arguing with the ethanol plant developers. There were claims circulating that it took more power to produce ethanol, than what you would get out of it. I still don't know what the truth to this is.


Well, a cost of 1c/km has been cited in some pages.
The FAQ states "Around $2 to fill up the air tanks"
It also states the autonomy for the car is 100-300 km, depending on speed.
It's an urban vehicle, and they suggest autonomy is 10 hours of driving in the city.
I haven't made calculations, but at first sight it seems very competitive with fuel, at least here in Europe.

Anyway, the biggest advantage imo would be having cleaner cities. I am getting tired of having more and more smoke in my city every year :( , I am the kind of person who likes to walk a lot every day.

[CFLarsen]

Q,

The real trick is “Maxwell’s Demon,” which we have discovered is the Bernoulli Effect: air pressure can be converted into air velocity (jet drive), so that in the localized absence of pressure (low pressure zone inside tank) the high velocity jet can induce low pressure air (continuous source of solar energy) into the tank without wasting a lot of energy compressing it to get it in. Because of air’s internal energy (heat that is there before and after the air is compressed), the power needed to generate compressed air is uniquely unrelated to the power available from the compressed air thus created. This gives the appearance of perpetual motion, but is not; it is a heat-pumping process.

OK. It's the "localized absence of pressure" inside the tank that does it. In other words, it fills up by itself.

Well, that settles it. :rolleyes:

Originally posted by Peskanov
CFLarsen, your link is NOT related to Guy Negre, or his company.
The owners of the page seems to be Scott Robertson and Terry Miller, and their company is unconnected to Guy Negre's invention (I think).

I merely followed the CNN link. Hm....seems that weirdos do move in herds....:D

[Ed]

Anyone remember that guy with the personal hovercraft/plane? He had a website with some odd video of a test? Two years ago maybe?

[DickK]

Originally posted by Ed
Anyone remember that guy with the personal hovercraft/plane? He had a website with some odd video of a test? Two years ago maybe? Yup, the link was on here somewhere. Looked like a prototype Seqway IIRC and was debunked by the poster (sorry, can't remember who) detailing the crass image editing involving the removal of a shadow or somesuch.

[Ed]

Originally posted by DickK
Yup, the link was on here somewhere. Looked like a prototype Seqway IIRC and was debunked by the poster (sorry, can't remember who) detailing the crass image editing involving the removal of a shadow or somesuch.

That's it. I recall that they posted a "roll out date". I love it when woos actually give dates.

[pupdog]

from Ed:Anyone remember that guy with the personal hovercraft/plane? That reminds me of Ford's Levicar. As a pup building car models in the 1960s, I recall getting a free bonus Levicar included with another model. And recently, I saw in a trade newsletter celebrating Ford's 5 trillionth (or so) unit rolling off the line a photo with a Levicar in the background. The model actually worked quite well, but I'm not sure how well the real vehicle would work on the highway--you had to blow into a tube to make the model go.

[Bikewer]

A few years ago, a local (Missouri) inventor showed a prototype of a compressed-air powered vehicle. The thing was essentially a dune-buggy type frame, with two large commercial air cylinders powering a piston-driven compressed-air engine. Supposedly the thing worked fairly well, though again we have the questions of how much it costs to compress the air to a usable state.

I never heard anything more about this particular device; maybe he got together with the above gentleman.

Working on the "no free lunch" situation, I'd be interested in seeing how much cost-to-compress (and the pollution produced therby) would compare with the vehicle's efficiency.

[Agammamon]

Well, there's already been talk of using compresed air for fleet taxis in Mexico City. Short rang, but these guys can fill up at each gas station. Has an added benefit. If you run the air through a filter before putting it into the tank (and have enough taxis converted) the cars sort of become negative pollution generators. However if this guy is just talking about tappign into the heat in the air he has to overcome 2 big obstacles.
1 heat engines work on the difference between 2 temperature. If the air in the tank is at 100F and the ambient temp is 80F you won't be able to extract much.
2 How do you keep the air in the tank hot once it's compressed? Without a lot of insulation the heat will bleed off.

[Peskanov]

CFLarsen,

I merely followed the CNN link. Hm....seems that weirdos do move in herds....


Well, it's pretty clear that the guys of www.aircaraccess.com are loonies (eternal-motion engines type).

However, Guy Negre is just offering an alternative to chemical batteries powered electric cars. His company is serious, the prototypes exist and has been tested. Take a look at MDI site.There is no magic technology behind them, is just another way to store energy, like flywheels for example.
Maybe the final product will not reach the expected efficiency, but come on, don't put him in the same league with those loonies!

[Mr. Skinny]

quote:
--------------------------------------------------------------------------------

How do the air tanks work and are there any issues with their safety?
One of the most frequently asked questions regards the safety of the air tanks, which store 90m3 of air at 300 bars of pressure. Many people ask whether this system is dangerous in case of an accident, and whether there is an explosion risk involved. The answer is NO. Why? Because the tanks are the ones already used to carry liquefied gases on some urban buses, and therefore make use of the technology that is already used to move buses on natural gas. That means that the tanks are prepared and certified to carry an explosive product: methane gas.

I seriously doubt that there is NO risk of an explosion, simply because they are currently in use in another system.

In the case of an accident, with air tank breakage, there would be no explosion or shattering, now that the tanks are not metallic. Due to the fact that they are made of glass fibre the tanks would crack longitudinally, and the air would escape, causing a strong buzzing sound with no dangerous factor. It is clear that if this technology has been tested and prepared to carry an inflammable and explosive gas, it can also be used to carry air.

I've seen composite pressure vessels that have exploded, and while they don't fail quite like metal vessels, they can produce quite a bit of shrapnel. If a tank fails, regardless of construction, and suddenly releases energy, I consider that an explosion.

A final matter with reference to the air tanks, is the improvement that MDI contributed to the original structure. In order to avoid the so-called 'rocket effect', this means to avoid the air escaping through one of the tank's extremities causing a pressure leak that could move the car, MDI made a small but important change in the design. The valve on the buses' tanks are placed on one of the extremities. MDI has placed the valve in the middle of the tank reducing the 'rocket effect' to a minimum.

This seems to assume that the tank will fail only at the valve. Suppose one of the hemispherical heads fails?

--------------------------------------------------------------------------------

[shecky]

I looked into this several months ago and the best I could find is that the cars do exist, but only in prototype and do not reach the predicted range yet, if ever.

A few years back there was a similar compressed gas auto. Actually IIRC, it stored liquid nitrogen, which turned in to high pressure gas as it warmed up to ambient temps (via some kind of radiator), which powered the engine in a similar manner to the compressed air engine. The exhaust was just nitrogen gas. I think the eventual conclusion was that it could be cost effective if a infrastructure could be developed.

So, it was basically a intersting doctoral project for a few students.

[Mr. Skinny]

Originally posted by shecky
I looked into this several months ago and the best I could find is that the cars do exist, but only in prototype and do not reach the predicted range yet, if ever.

A few years back there was a similar compressed gas auto. Actually IIRC, it stored liquid nitrogen, which turned in to high pressure gas as it warmed up to ambient temps (via some kind of radiator), which powered the engine in a similar manner to the compressed air engine. The exhaust was just nitrogen gas. I think the eventual conclusion was that it could be cost effective if a infrastructure could be developed.

So, it was basically a intersting doctoral project for a few students.
We have several large outdoor liquid nitrogen tanks where I work and they have a heat exchanger on them to allow the liquid to expand back to a gaseous state. They usually have rather large chunks of ice (sometimes up to 24-30 inches in circumfrence) on the 3/4 inch heat exchanger tubes.

I image that would work well to air condition the car in summer time.

I can't imagine self-serve liquid nitrogen filling stations though, at least at this point. I'll try to remember to ask what LN2 goes for a gallon these days when I get to work on Tuesday.

[!Xx+-Rational-+xX!]

Skeptics should suppress this! It’s our job to be hostile towards any major changes to uphold our currently accepted views of how the world is!