Air Car

what's an air car?

There are steam cars, compressed air cars, and liquid air cars. There should also be another category, which, for simplicity, could be called wet compressed air (WCA) cars.

Steam cars are old technology. They reached a peak, technologically, about 1930 and then disappeared from the market place. While they can meet pollution standards, have good performance, etc., they are only about 15 per cent efficient, so gasolene/kerosene/propane miles per gallon would not be competitive with IC engine driven cars. They also consume a lot of water, unless there is a condenser, which there is not, for reasons of space, etc. Someday, perhaps because of fuel supply problems, steam will once again flourish. The US Navy (Gotta love those traditionalists!) at one time researched steam driven airplanes. Nowadays, even "steamships" use diesels or gas turbines.

Compressed air cars are "steam cars" with a compressed air tank replacing the boiler. The Midi and the "Spirit of Joplin" are examples. Their efficiency is also limited, roughly 15 per cent.

Liquid air cars are "steam cars" with the boiler replaced by a container of liquid air and a heat exchanger. Typically, ambient air is used to boil the liquid air, which then powers the vehicle as compressed air. The advantage is the density of liquid air, as compared with compressed air. The disadvantages are many, not the least of which is that they leave a cloud behind them, and the overall efficency is not high.

The steam car is inefficent because it starts with a liquid and ends with a gasseous exhaust. The latent heat of vaporization is lost in the exhaust. The compressed air car is inefficient because the air is compressed isothermally; the compressor is air cooled and the heat is wasted. Then, of course, when the ambient temperature compressed air is expanded, the exhaust is cold, and there is that cloud again. It's not only the visibility problem; it includes moisture freezing, making for slippery roads.

So lets undertake a thought experiment. If I have an insulated compressor (piston in cylinder) and compress the ambient air adiabatically (no loss of heat), I will end up with hot compressed air (as in the compression stroke of a diesel engine). If it then expands adiabatically, the inverse of compression, perhaps in the same mechanism, one arrives back at the starting point, air at ambient temperature and pressure. Thermodynamically, the process is "100 per cent" efficient, a reversible process. If one could store the hot compressed air in insulated tanks, it would still be a very efficient means of energy storage, more efficient than, for instance, current electrochemical storage batteries. The mechanical energy output of the expander is the same as the mechanical energy input to the compressor (less a little unavoidable increase in entropy) But the problem is that the compressed air is hot, too hot to handle conveniently. That's why high-prssure commericial air systems try to approach isothermal compression, with multistage compressors and intercoolers between the stages. (I think it goes without saying that a practical air car will use high pressure air to allow enough energy storage. A low-pressure air car woulld look like a Zeppelin on wheels)

Suppose I repeat my adiabatic compression experiment when it is raining, and water droplets find their way into the air going into the compressor. The air heats up as it is compressed, and the water heats up, too, and, golly, it absorbs a whole lot of heat turning into steam, so the mixture of compressed air and steam is cooler than the air alone. Note that, in the closed system of the compressor, no heat has been lost; it is still an isentropic process. When the mixture expands, the air cools, and the steam condenses, reheating the air. The exhaust is ambient temperature air with water droplets in it, exactly what we started with, except the water is now distilled and drinkable. "All" the energy put into compression is recovered during expansion.

This is the trick the Germans used in their diesel-pneumatic locomotive. They took an ordianary steam locomotive and replaced the boiler with a diesel engine driving an air compressor, which was cooled by injecting water, producing a steam-air mixture. An extra bit of cleverness used the diesel engine exhaust to further heat the steam-air mixture, which was then fed to the steam engine. Pulling the same train, over the same route, on the same schedule, they used 29 per cent less fuel than the diesel-electric locomotive which used the same diesel engine. Unfortunately, in the real world, good ideas only have a small chance of getting through the bureaucracies to fruition, and this one lost out to The Great Depression and Germany's lack of domestic oil supplies. No-way would they dieselize in 1930.

I call that steam-air mixture wet compressed air (WCA), and WCA is the way to build an air car. Limiting temperatures to about 300 C for easy storage and storing the mixture at tens of Bar pressure, it should be possible to outperform electric cars at much lower price, using no scarce, toxic materials. The compressor can be driven by an electric motor, or, ideally by a wind turbine or other "green" energy source. The WCA thus produced and stored can be use to power vehicles, electric generator sets, for domestic heating and cooling, etc. PLEASE CRITIQUE THIS.

Hello, this is PentaPower and I believe that if we all work together we can come up with a car to win the XPrize. I was thinking of adding my forced fluid energy recovery system with other devices and think that you hit the nail on the head. If a turbine could use the forced air on moving vehicles and create electricity efficiently, then powering a compressor to fill the tanks and give power through the motor. Why not? So many people think that this is impossible, but I am starting to wonder. Just like my turbine, which I am getting tested at present, I can force air in and it will spin faster than the air forced in and virtually no air will escape. How is this possible? you have to see it to believe it. You can go to www.pentapowerturbines.com and see a little of what I have. I'm sure there are alot of people that have had different thoughts that others have said were not possible. Some people give up and the ones who pursue give strenght to the cause. Thanks. PentaPower.

If you are thinking you can drive the turbine with the "wind" of air moving relative to a moving vehicle, you are in deep trouble, physics-wise. The added drag on the vehicle will consume more power from the driving motor than you can get from the turbine. (The turbine might be great on a mountain top with "God's" wind, which is free) Also, using the turbine to make electricity to power an electric motor to compress air will be more expensive and lose more energy than letting the turbine drive the compressor directly.

Thanks for your reply. If more people could think out-of-the-box, we could get more productive. Most laws of physics were made a long time ago from people who had ideas and most times no one refuted them. In todays age with our new technology(which we had to invent or should we say improve on) we have done things that were thought to be impossible back then. You have also had some creative thoughts that maybe no one before has had. Sometimes many innovative ideas are kept from the public as there are ones who feel threatened from them(ideas). I'm sure that all of you out there know some of what I'm suggesting. Just keep the ideas flowing and the products coming. As we know, there are few things that we have not yet been able to improve on. Thanks. PentaPower.

Do you really believe that you can mount your horizontal turbine on top of a car and have a net energy gain?

Have you tried it?

Why not?

Thanks for your reply. If you put my turbine anywhere on a moving vehicle, with the proper scoop and cover, it should be able to generate some power. With it being cylindrical and aerodynamic, the air, being forced in at the right angle, is almost completely used causing(theoretically)little or no drag. For the ones who don't think that it is possible, then give some thought as to how it can. It is possible if done the right way. Thanks. PentaPower.

I don't know if I would be comfortable riding in a vehicle with that much pressure stored in a tank. Sounds like a rolling bomb.

Somewhat old technology, as I have seen old rusting air cars around old mine sites. They old ones only operated at 4-500 psi as compared to the 4400 psi proposed, but the technology is similar. I haven't run any numbers recently on cost of compressed air, but I am suspicious of the claimed cost per mile. Usually for manufacturing plants, compressed air is the most expensive source of energy, more expensive than steam or electricity.

Yes, commercial compressed air systems are typically only about 15 per cent efficient. However, it was demonstrated way back in 1930 that power transmission by compressed air, a "diesel pneumatic" drive for locomotives, can be more efficient than diesel-electric. My patent, #5,832,728, shows how to do it for an air car.

The auto-xprize offers $millions for a four passenger car which can get 100 miles per gallon of gasoline or "gasoline equivalent", go 100 miles unrefueled, and cost less than $80,000. My Prius can get 50 mpg, but the prime mover, an IC engine, probably isn't better than 25 % efficient. 50 % would win the prize. That can be achieved using an electric motor to drive a compressor and a "steam" engine in the car. (Batteries for 100 mile range would cost more than the rules allow. Air tanks are cheaper.)

One must also have a business plan to take deposits and deliver up to 10,000 of the winning vehicles. I'm looking for an automobile manufacturer or distributor to team with in the competition, modifying an existing vehicle.

"However, it was demonstrated way back in 1930 that power transmission by compressed air, a "diesel pneumatic" drive for locomotives, can be more efficient than diesel-electric."

IF the diesel-pneumatic drive is better than a diesel-electric drive for locomotives why has it not replaced them?

"My patent, #5,832,728, shows how to do it for an air car."

What became of the company Pneumocon Inc. and the Spirit of Joplin Air Car?

A BRIEF HISTORY OF AIR CARS

Perhaps you can join forces with Guy Negre and make your fortunes in selling futures in air cars as a team ?

In 1930, the German railroads were not about to go with diesels. They had no reliable supply of oil, and the economy was in bad shape. While there were magazine and journal articles about the locomotive, they were a bit reticent to reveal all, and, without the "trick", I'm sure people were skeptical of the reported fuel savings. And then it was a case of out of sight, out of mind. After WW-II, engineers were sure that diesel-electric was the way to go, and probably no one thought "out of the box". When I was applying for my patent, none of the searches turned up the German work (done in cooperation with Russia!), which may have been regarded as a trade secret and not patented. I only found out about it by accident on a model railroad site which pictured one-off locomotives.

You don't think riding with 20 gallons of gasoline isn't riding with a bomb?

In spite of what you may have seen in "Jaws", air tanks do not explode; they leak. At worst (say an unsecured tank with the regulator knocked off) they take off like a rocket, but when built into a vehicle that is not possible. On "Mythbusters" (TV program), they tried to make a tank explode by shooting at it. There was no way.

There was a case of an aluminum tank "exploding", but aluminum air tanks are about as dumb as aluminum wheels or aluminum bridges; they crack before they bend.

Talk to them direct--they will give you a franchise for your country.

http://www.gvnr.com/89/6.htm

If you need a push-give us a shout-- "HELP"!!

"Talk to them direct--they will give you a franchise for your country."

They will GIVE you nothing but will let you sign a contract for exclusive right to manufacture the car in a "turn key" factory that they will set up for you....AT A PRICE!

The Midi Air Car has been promised to be in production "SOON" for four or five years! Take a good contract lawyer with you when you talk to them to protect your interests.

Be sure to read all of the fine print in their web sites. Very enlightening.

This guy sounds like a plant.

-A-

Maybe he means skycar ....

http://www.moller.com/

????

very cool car/aircraft.