NEWS: 100MPG air-powered car to be in America by 2009

[NoCO2]

http://www.popularmechanics.com/auto...html?series=19

Originally Posted by popularmechanics.com

'Company officials want to make the first air-powered car to hit U.S. roads a $17,800, 75-hp equivalent, six-seat modified version of MDI’s CityCAT'...'that, thanks to an even more radical engine, is said to travel as far as 1000 miles at up to 96 mph with each tiny fill-up.'

[bestmapman]

This will be great if it comes true.

[Gone4]

The MPG estimates will probably be way off. As it is, the numbers they throw around seem to be coming from the assumption that you compressed air into the tank for free before you started your drive. Regardless, a technology that boosts efficiency without the environmentally detrimental effects that battery production tends to incur, is an excellent thing.

[NoCO2]

I'm just impressed more by the fact that someone is actually, at least, trying to make air powered cars work. I have always liked the idea of being able to pull my fuel right out of the air I'm driving through. Even if they make it something like a hybrid where it cruises on gas and accelerates up the 35mph (like the article stated they were planning). Using a compressor hooked up to the engine to refill the air tank once at speed would be just as efficient as any hybrid is today without the worry of replacing batteries, etc.

[basjoos]

I wonder how they are getting around compressed air's inherent inefficiencies. A lot of heat is produced when air is compressed. On large compressors, this heat is usually removed with a heat exchanger at the output of the compressor, allowing them to store a greater quantity of room temperature compressed air rather then a lesser quantity of heated air. Then when the compressed air is expanded to room pressure, its temperature drops precipitouosly. That air heater they use at speeds over 35mph looks like a method to try to compensate for expansion cooling of their compressed air to increase their range. And if you talk to anyone in industry who runs a compressed air system, compressed air is not cheap to produce and can be one of a plant's larger electrical expenses.

[Ryland]

I suspect that the main reason they are adding the gas engine to these cars is that air powered cars in cold climets don't really work! every design that I have seen for an air powered car has a radiator to warm the air befor it goes to the air motor, and that a commen problem in humid enviroments is that radiator freezing up.
I did read an interesting artical a while back about a liquid nitrogen hybrid electric, were the nitrogen cooled the wires, and motor bringing making them better conductors of electricity, and that in turn made the nitrogen boil/expand so that it could turn a turbine that ran a generator that powered the car...

My dad works at a university and has said that their air compressers are alwas being repaired, and have huge motors on them that draw tons of power, and that is just to compress air to 1/10 of the presure that an air powered car would need.

[wumpus]

Anyone know the expected lifespan of an off the shelf turbo charger if run semi- continuously? This would give you an off the shelf compressor and power source. Generally turbines are as highly efficient as you can get, but there really isn't any need to do so with turbos (it's waste anyway), so I don't know how much it would help.

There have been other suggestions with diesel and otto engines (requiring magic valves), but this could presumably use off the shelf parts.

[trebuchet03]

I know it's nit picky... but air is not the fuel for this car... Air is just the energy storage medium - the battery. The fuel will be whatever ultimately drives the compressor (gas, coal, hydro, etc.)... I hope it has regenerative braking

Also, NoCO2 - the 100mpg was just speculation by the article writer....

I am curious as to how they're keeping it from freezing. As the whole system does generate heat, I imagine that with proper controls that problem would be minimized. I'm also curious as to what pressures they're dealing with.

[WaxyChicken]

Looks familure... Tato Nano anyone?

[basjoos]

I wonder how the efficiency of a series pneumatic hybrid would compare with that of a series electric hybrid. A series electric hybrid is of course a small IC engine driving a generator, feeding a battery, which powers an electric motor. A series pneumatic hybrid would be an small IC engine driving an air compressor, feeding a pressure tank (insulated to retain the heat of the compressed air), which powers an air motor. If the tank was well insulated, then the air motor's exhaust temperature should be close to the temperature of the air before it was compressed, thus almost eliminating one major cause of pneumatic system inefficiency. So you would have the weight of the compressed air tanks versus the weight of the batteries. Also the energy conversion efficiencies of the electric generator, electric motor, batteries, and voltage controller circuitry versus the efficiencies of the compressor, air motor, and heat loss from the air tanks and air lines.