Tata Airpod

The Old Medic

Council Member
May 16, 2010
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The World
Actually, the TATA is a VERY efficient vehicle, for short distances.

It is meant for urban settings, not for highway use. It would be practical in some cities, but virtually useless in most of North America, where we often tend to drive a lot.

This was the problem for many European and Asian vehicles, for many years. They were great for short distance driving, but could not stand up to the stresses of being driven for many miles repeatedly. Peugeot, Simca, Fiat, etc. all eventually failed in the North American market, because their cars just fell apart under the driving conditions here. (NOTE: I personally owned 2 Simca's, one of which I shipped back from Germany when I returned Stateside. It was a great car in Europe, but just couldn't cope with driving some 500 miles a week.)
 

Misty666

Time Out
Aug 23, 2012
8
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1
How about this for an idea. Treat a compressed air car just like a super efficient electric car. Have a large high pressure airtank ( surely lighter and more relable than batteries over a long time ). Keep it topped up by a small 4 stroke engine running at constant speed with a very long stroke in order to take full advantage of the adiabatic expansion. Acceleration is handled by the Compressed. Air. The tank can be topped up on cruising and by using engine breaking - switch off fuel and engage 4 stroke, this implies that the engine and compressor are integrated with some cylinders used for compression or switched to 4 stroke when necessary.
 

TenPenny

Hall of Fame Member
Jun 9, 2004
17,467
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Location, Location
That idea would be extremely inefficient. Compressed air as an energy storage medium is extremely inefficient, you would be far better off doing what is done now - using electricity as the energy storage medium.

There is a reason why railroad locomotives use diesel engines to drive generators that run the electric motors on the axles - because it can be done very, very efficiently. They've been working on this since the 1920s.
 

Misty666

Time Out
Aug 23, 2012
8
0
1
That idea would be extremely inefficient. Compressed air as an energy storage medium is extremely inefficient, you would be far better off doing what is done now - using electricity as the energy storage medium.

There is a reason why railroad locomotives use diesel engines to drive generators that run the electric motors on the axles - because it can be done very, very efficiently. They've been working on this since the 1920s.



Yes you are using energy to heat the air in compression but since the action is fairly continuous you could use this 'hot' air to 'cool' the 4 stroke part of the combined engine/compressor then store this hot air in a themally insulated tank. When expanding the air to drive pistons work can be extracted both from the compression and the heat.
I have in fact posted elsewhere the concept of a very small super efficient single speed 4 stroke charging up an electric battery which would deal with the short period demands of high torque and power under road conditions. Although indeed this would be far more efficient you have the problem of the cost and damage to the environment in manufacture of batteries together with their very heavy weight and short lifetimes.
Any car manufactures who wish to take up my idea please reply!!!!!!!!
 

Bar Sinister

Executive Branch Member
Jan 17, 2010
8,252
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Edmonton
That has nothing to do with the fact that compressed air is very inefficient as an energy storage. It typically takes 4 to 5 hp to produce enough compressed air to do 1 hp worth of work.

True enough. But don't internal combustion engines generally have the same problem? It seems to me that a great deal of energy in gasoline and other fuels is wasted in the form of heat. If I remember correctly the average gasoline powered engine is only about 20 to 30% efficient, which makes it about the same as the Tata engine.