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MisterHeron
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02 Mar 2008, 8:45 pm

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India’s largest automaker is set to start producing the world’s first commercial air-powered vehicle. The Air Car, developed by ex-Formula One engineer Guy Nègre for Luxembourg-based MDI, uses compressed air, as opposed to the gas-and-oxygen explosions of internal-combustion models, to push its engine’s pistons. Some 6000 zero-emissions Air Cars are scheduled to hit Indian streets in August of 2008.

Barring any last-minute design changes on the way to production, the Air Car should be surprisingly practical. The $12,700 CityCAT, one of a handful of planned Air Car models, can hit 68 mph and has a range of 125 miles. It will take only a few minutes for the CityCAT to refuel at gas stations equipped with custom air compressor units; MDI says it should cost around $2 to fill the car’s carbon-fiber tanks with 340 liters of air at 4350 psi. Drivers also will be able to plug into the electrical grid and use the car’s built-in compressor to refill the tanks in about 4 hours.

Of course, the Air Car will likely never hit American shores, especially considering its all-glue construction. But that doesn’t mean the major automakers can write it off as a bizarre Indian experiment — MDI has signed deals to bring its design to 12 more countries, including Germany, Israel and South Africa.

Popular Mechanics

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And here it is, the air car. India's largest auto maker will build a zero emissions car that runs on compressed air. The car will cost $12,700. It's got a range of about 125 miles and get this, can hit 68 miles per hour.

CNN

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But perhaps an even more environmentally-friendly car than the EV is the Air Car, which is an Indian invention. The Air Car runs on nothing but compressed air and can be easily filled up at any gas station. All the car needs is 320 liters of air, which will cost Indian consumers around $2, according to Popular Mechanics.

If consumers don't want to even pay for that, they can plug their car into the local grid and an in-built air compressor will do the job in 4 hours. Air Car is due to launch in India this August and 12 countries including Germany, Israel and South Africa have placed orders with Air Car's manufacturer Luxemboug-based MDI.

CNN

The best part is you can charge this sucker up at home, without having any need to visit your local gas station. Too bad we won't get this thing in America...



Fuzzy
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02 Mar 2008, 11:13 pm

4350 lbs per square inch propelling shattered razor edged chunks of carbon fiber in an accident.

Also, as you hit empty, your top speed would plummet.



MisterHeron
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03 Mar 2008, 4:34 am

Fuzzy wrote:
4350 lbs per square inch propelling shattered razor edged chunks of carbon fiber in an accident.

Also, as you hit empty, your top speed would plummet.

Carbon fiber tanks don't shatter. They just split open. They had a deal on that recently on the Discovery Channel. I do understand the point about top speed though, which is why you wouldn't want to push the maximum...



yesplease
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03 Mar 2008, 8:26 am

Fuzzy wrote:
4350 lbs per square inch propelling shattered razor edged chunks of carbon fiber in an accident.
No.

Fuzzy wrote:
Also, as you hit empty, your top speed would plummet.
Yes.



Fuzzy
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04 Mar 2008, 2:59 am

yesplease wrote:
Fuzzy wrote:
4350 lbs per square inch propelling shattered razor edged chunks of carbon fiber in an accident.
No.

Good.

yesplease wrote:
Fuzzy wrote:
Also, as you hit empty, your top speed would plummet.
Yes.


Or maybe far sooner.



yesplease
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06 Mar 2008, 3:00 am

Fuzzy wrote:
yesplease wrote:
Fuzzy wrote:
Also, as you hit empty, your top speed would plummet.
Yes.


Or maybe far sooner.
I doubt it. In fact, there was a provision for a fueled "heater" that will allow much more range and higher top speed IIRC.



Fuzzy
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06 Mar 2008, 3:33 am

Yeah, you could heat the air to increase the pressure. But its still zero sum; you are taking energy from the air tank to do things. Heating would hasten that energy loss. Once you introduce a energy re claimant system you increase the weight(taking more energy to propel the vehicle), and/or increase the friction, again, requiring more energy.



yesplease
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06 Mar 2008, 6:58 am

I don't think the tank air is involved much with the "heater".

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In the Australasian applications we do not intend to use compressed air refilling point to any significant extent. It is important to realise that the main version of the MDI engine is designed to run in multi-fuel mode. That is to say that (1) it makes it's own compressed air through the burning of a fuel that takes place inside a heater/combustor located outside the engine. Because the primary energy input takes place outside the engine, it is possible to use any fuel, petrol, diesel, natural gas, LPG, or preferably "green" biofuels like rapeseed oil, ethanol from sugarcane, and so on.

Because the system (compressed gas engine and external heater/burner) is much more energy efficient than an internal combustion engine the amount of biofuel required per 100 km is considerably reduced. The present system is capable of running on 2 litres per 100km. As far as I know no other engine can achieve this.

[...]

This refers to what I outlined above. The engine takes air from the outside and compresses to 30 bar. It pushes this 30 bar compressed air through the external heater/combustor where the air is heated at constant pressure by a flame. A gas heated in this fashion expands. So through the application of heat, each cubic centimetre of air at 30 bar injected in the heating module is expanded to 3 to 5 times.

This expanded air is then returned to the engine where it pushes the pistons. The overall energy balance is very positive (power available at the crankshaft less power used to compressed the air intake). The design of the engine itself makes it twice more energy efficient than an internal combustion engine. The external combustion takes place in a steady fashion (no explosions and in internal combustion engines), at much lower temperatures (less than 860oC instead of around 2000 oC) and in an excess of oxygen (which means a very lean and clean combustion that does not produces any significant levels of uncombusted particulates or NOx pollutants).

The fact that the combustion is external means that one has a wide choice of fuels without having to change the engine, only the fuel supply parameters to operate the burner require adjusting when changing from one fuel to another. This is done through a computerised system.



SuedeIII
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08 Mar 2008, 3:36 am

Interesting. A full scale AIR JAMMER ROAD RAMMER!



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08 Mar 2008, 11:48 am

If you were to attach an air compressor to the engine that is powered via belt, you could simultaneously refuel the car while driving it.
Just an idea that's been tossed around.


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Tensho
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08 Mar 2008, 12:24 pm

It must sound like your riding a fart.



Fuzzy
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08 Mar 2008, 5:20 pm

JohnnyCarcinogen wrote:
If you were to attach an air compressor to the engine that is powered via belt, you could simultaneously refuel the car while driving it.
Just an idea that's been tossed around.


Do you mean power the transmission with air, or a catalyst(perhaps petroleum) based engine powers the air compressor which in turn provides motive power to the vehicle?



SuedeIII
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08 Mar 2008, 7:05 pm

JohnnyCarcinogen wrote:
If you were to attach an air compressor to the engine that is powered via belt, you could simultaneously refuel the car while driving it.
Just an idea that's been tossed around.


Heh...

[youtube]http://www.youtube.com/watch?v=wvRzWYCZ2e0[/youtube]



JohnnyCarcinogen
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09 Mar 2008, 12:58 pm

Fuzzy wrote:
JohnnyCarcinogen wrote:
If you were to attach an air compressor to the engine that is powered via belt, you could simultaneously refuel the car while driving it.
Just an idea that's been tossed around.


Do you mean power the transmission with air, or a catalyst(perhaps petroleum) based engine powers the air compressor which in turn provides motive power to the vehicle?


Actually, I meant that the engine that is powered by compressed air would turn an air compressor at the same time, in the same way a car engine that uses a battery continually recharges said battery via alternator. Basically the air compressor would continually fill the air tank with air as it was being used to power the engine.

If that cleared the air, good. If it didn't, DAMN.


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SuedeIII
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09 Mar 2008, 2:18 pm

JohnnyCarcinogen wrote:

Actually, I meant that the engine that is powered by compressed air would turn an air compressor at the same time, in the same way a car engine that uses a battery continually recharges said battery via alternator. Basically the air compressor would continually fill the air tank with air as it was being used to power the engine.


Oh I got ya. Sorry if it seemed as if I was confused or making fun...

Your car engine example doesn't apply. The engine isn't running directly from the battery, it's using fuel and converting it to other forms of energy.

What you're trying to say , I think, is more akin to an electric motor turning a generator that's providing the power to the motor.

If things were 100% efficient at energy conversion... i.e. no friction, resistance, heat... then that concept works. But there's always losses. Your compressor would consume more air than it produced.

Hence the silly little perpetual motion vid... :wink:

JohnnyCarcinogen wrote:
If that cleared the air, good. If it didn't, DAMN.