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Compressed-Air Car Nears Trial
DeviceGuru writes "Air France and KLM have announced plans to conduct a six-month trial of a new zero-emission, compressed-air powered vehicle. The AirPod seats three, can do 28 mph, and goes about 135 miles on a tank of compressed air. Motor Development International, the vehicle's developer, expects the AirPod to reach production by mid-2009, and to sell for around 6,000 Euro. Initially, it will be manufactured in India by Tata Motors, and distributed in France and India."
Parts of this thing will get fucking cold. Just imagine all the heat lost when the compressed air is let to cool down.
Oh well, not like I care about the environment or anything.
How much energy is required to run the compressor to fill the high pressure air cylinders?
Obviously more than you get out of the drive line at the other end of the system. Compressed air does lose lot of energy to heat.
In fact calculating energy loss would almost be a textbook example in thermodynamics.
http://michaelsmith.id.au
I don't know about the US, but most European cities have speed limits of 50 km/h (around 31 mph), so it's not that far of.
Actually, I would not mind this type of car getting popular, since it would lower the air and noise pollution in crammed cities quite considerably.
/ The Arrow
"How lovely you are. So lovely in my straightjacket..." - Nny
Yes, but you can run the compressor with a coal powered boiler, a windmill, a team of oxen, a dam, or a volcanic heat outlet. It's not the power or the efficiency that matters, it's the style with which you transform that energy. Steam-punk FTW!
The article says there are 4 other models planned, with one reaching speeds of 70mph... It also seems to hint that the initial models are being used as maintenance vehicles and such. Their first major test buyer is Air France. Its more like their initial models are looking to replace electric cars in the workplace, not for high way driving. But of course you knew all of this, because no one comments without first reading the article.
Which can be dealt with more effectively than it can on each car.
Here is a vehicle that is not as fast as 28MPH and its so popular that I can continuously hear their sound as I type this: Auto Rikshaw
Uh, no. It's not a heat engine, because heat is not causing expansion. In fact, as you point out, as it expands, it cools. This actually robs power from the engine! If the engine were to be heated somehow, it would probably be substantially more efficient. It is no more accurate to describe MDI's air engine as a "heat engine" than to describe a single pneumatic cylinder being driven by a compressor and used to do work as a "heat engine" - or by extension, a hydraulic cylinder. (Saying that liquids "don't compress" is a simplification of real-world physics, after all.) The heat is A) a byproduct of the gas compression problem, B) is not used to do work, and C) does not increase overall anyway. You don't actually increase heat energy when you compress a gas, aside from the wasted energy converted to heat by the compressor. You increase temperature, but only because you've put more mass into the same space. The heat per unit of mass does not change and that is why this is not a heat engine.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Watching the video, I thought, "great, a jackhammer that drives around."
Still, it's a cool idea, especially if you build something like an exercise-bike powered air compressor. If filling the whole tank this way is too much work, you could use it to put a few psi in the tank.
My grandmother used anecdotal evidence all the time, and she lived to be 120 years old.
You have concisely outlined here why oil is such a fantastic energy source. The stored potential energy in a tank of fuel is enormous, the ease by which it is transported is unprecedented in all our technology.
Fancy alternatives all fail at these incredibly important factors which add up to why we use oil. Personally I believe the best solution to our dirty energy problems is to make carbon neutral oil and use that. Its energy intensive to do but oil is so damn useful, and to hell with the current fads.