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Air-Powered Cars
Azanian writes: "Here is an interesting article about a French-designed 'compressed-air' powered car being unveiled in Johannesburg (South Africa) later this week. The first of these 'alternative-energy' zero-emission cars are scheduled to roll of the production line in June 2001." It ain't a hover car, but it looks interesting (a full day's driving on 3 hours of air compression,
with dramatically less power consumption). Sounds almost too good. Course the auto companies keep this out of our hands like they do with the engine powered by water *grin*.
If you ever had one of those cheap "air-pump + water" rockets as a kid you know what I'm thinking
That a lot of these cars will get stuck on the roof?
I'm gonna invent myself a wind up car! Then we will see who has the better alternative energy source...
Friends don't let friends use multiple inheritance.
Like most of the so-called Zero Emission vehicles this just relocates the emissions. The car just puts out air, but the horsepower to compress that air came from somewhere. Unless the compressor is run by wind, solar, or hydro power it probably results in a net increase in total emissions.
You never really know how close to the edge you can go until you fall off.
If you want an air-powered car, I think they guys at TriTec Power have a better solution with their power unit that can be adapted for just about any vehicle. It doesn't run on air per se, but it can run on any expanding gas. Steam (made by combusting diesel, gas, hydrogen, whatever), compressed air, liquid nitrogen... anything. Just imagine how much farther you could go with a tank of liquid nitrogen in your trunk expanding. I don't know the figures for N2, but for our old friend H20, it expands by a factor of 1700 times going from liquid to gas. That's nearly 6x what you'd get compressing a gas to 300 atmospheres.
For the record, assuming their claims of 200km per "tank" and 130km/h, I'd be right there getting one if they came here. Just think how damned quiet it could be. Yeah.
Mr. Ska
1) The constant farting sound of air blowing out the back end
2) Can't steer, car just flys around the room
3) High internal pressure means that exiting car too rapidly causes "explosive decompression"
4) After car has run for several hours, outer surface gets all wrinkly
--
An abstained vote is a vote for Bush and Gore.
Non-meta-modded "Overrated" mods are killing Slashdot
(Hey Ryan! Here's your proof!)
Think again.
The total loss would still be the same, it would
just be smaller per time unit.
"Source... The Final Frontier" -- keepersoflists.org
Actually, the catalytic converter is a very good argument for the point you seem to be arguing against. A Japanese company (Honda, I think) had a lean-burn engine that emitted less polution than conventional engines with converters. Because of US (read: Californian) regulations requiring converters, they were unable to introduce cars powered by these engines to the States. The result was more polution than would have been the case if the regulations had not applied, at least in this case. This is a problem with mandating means rather than results, and is widespread in American government ($10,000 hammer, anyone?).
While there would be no guarantee that a few hundred polution sources would be any more sensibly regulated than many million cars are, at least correcting regulatory screw-ups would be a lot easier.
It doesn't say in the article, but I imagine there's more than a cubic metre - probably more like 1.5 or 2. They also don't say what pressure the air is stored at.
;) The auto industry is, however, fairly mature despite its relative youth(only going back a couple of hundred years at most, if you count the first steam-engine tests and such).
There is one thing to keep in mind - we've all been spoilt by e-Press e-Releases. This company already has two factories making these things, and the African government has already bought a budle of 'em. They'll be there before the year's end, by the sounds of it. This is obviously *not* vapourware.
Anothing thing to keep in mind is the industry that we're talking about. The "computer" industry is still very immature, and it acts that way - look at Rambus, look at Intel, look at Microsoft. For most other industries, to even *try* to bullshit your customers(especially governments) would spell instant death. And don't think that governments don't know exactly what's going on
The BBC could be mis-reporting that these vehicles will get 10hrs at 80km/h off one fill-up, but I doubt it.
Dave
'Round the firewall,
Out the modem,
Through the router,
Down the wire,
Barclay family motto:
Aut agere aut mori.
(Either action or death.)
This car doesn't run on compressed air. It runs on gasoline or diesel fuel. The compressed air tank is used to provide supercharging for an internal combustion engine of unusual design. It's a highly supercharged lean-burn engine, but that's not "zero pollution". There are no reports of third-party tests of the engine, although prototype vehicles are pictured. (You'd think that if it worked they'd at least drive it to a service station that has smog-measurement equipment.) It's not clear why this arrangement is supposed to be better than an ordinary supercharger.
Nor does the factory exist. They're still trying to get financing. They claim to be able to build a factory for $8 million, which is very low for an auto plant.
Something is bogus here.
The link in the article didn't work, but here's another about the same thing. At a price tag of $10,000 I'd have to consider it for a commute to work car. And at a price of 30 cents for 120 miles??? You know the oil companies hate to hear about this stuff. So does OPEC. :)
"Say no more..." - Monty Python
Relocating the emissions can be a good thing, even if they (temporarily) increase. Right now, all the emissions are from "non-point sources"--meaning from cars that are zooming around everywhere. But if all the emissions could be centralized into a few power plants, it's a LOT easier to apply some emission reducing technology to the problem. Just think about the logistics (and legalistics) of making all car drivers install some kind of filter or post-processor compared to doing the same for a few power plant owners.
Furthermore, it modularizes the problem. Instead of having to come up with an engine for a car (which has to be small, high-power, light, and various other characteristics that vary by car) you can extract all those issues to the power plant where size, weight, cost, etc aren't as important. Imagine, for simplicity, that we were all driving electric cars but that our electric infrastructure was coal-based. Just replace those coal-plants with fusion plants (or solar, or whatever) and the change is transparent to the rest of society.
This is just like putting wrapper calls around malloc/free--you have all the same memory management issues to deal with, but in only one location.
--
An abstained vote is a vote for Bush and Gore.
Non-meta-modded "Overrated" mods are killing Slashdot
(Hey Ryan! Here's your proof!)
If it was a hot air car, I could run it off my boss - finally, turning him into a useful resource. More generally, We could power entire public transportation systems simply by holding regular meetings to discuss great new e-commerce ideas with venture capitalists.
Here is the Company that makes the Air powered cars.
h tml
Someone please mirror important stuff before it gets dotted.
http://www.zeropollution.com/zeropollution/index.
Only on slashdot would someone use a programming analogy to explain an automotive system!
But the Carnot cycle states that the efficiency is increased when the combustion temperature is increased.
For the average IC engine made of materials that you can afford, the maximum theoretical efficiency is 40%.
If you double the difference (in Kelvin) of the combustion temperature and the ambient temperature, you would get 80%. But this would melt an engine composed of normal alloys.
So, it's more efficient to have the electrical powerplant do the combustion, they can afford a turbine that burns at 2,000 degrees and is made out of tungsten-nickel alloys.
Ultimately, ceramic engines will yeild a huge increase in efficiency, but they are a aways away.
Well I'm skeptical. It comes down, as always, to the dull and tedious issue of energy density. My back-of-envelope scribblings tell me a cubic metre of air at 300 bar stores about 30 megajoules. That's only 8 kWh. I don't see that little energy lasting any longer than about half an hour: nowhere near the endurance figures mentioned in the article.
Oh yeah, compressed gas is dangerous. All of the work you put into it can be released instantly if your tank busts. This of course, is bad for people that get in the way. It happens from time to time, especialy when people screw up and put the wrong pressure in a cylinder. Boom, like a bomb. Failures in accidents will be less interesting, but knocking off the valve can give you a thousand pounds of force for a few seconds. If the cylinder is not held down well, it will fly around like a balloon. This is also very bad for people who get in the way.
All of that said, this might be cost effective if you do all of your gas compresion with cheap nuclear or hydro generated electricity. I have my doubts. Natural gas prices are comming up, :(. Windmills, solar and all that, forget it, it will be cheaper to burn oil.
Poster would rather ride his bike.
Friends don't help friends install M$ junk.
Power lines are a lot more efficient than you think, too. I'm having a bitch of a time locating the resistivity of typical aluminum transmission wire (AskJeeves is turning out to be useless), but if we assume that the lengthwise resistivity of the alloy as used would be about 3 times that of pure Al or about 8 micro-ohm meters, the wire has a cross-sectional area of 10 square cm and it carries a current of 50 amps at a voltage of 500,000 volts (25 megawatts) for 160 kilometers, we see that:
- The resistance is 8e(-6)/1e(-3) = 8e(-3) ohms/meter, or about 1300 ohms over 160 km.
- Total voltage drop is 1300 ohms * 50 amps = 65,000 volts.
- This is 13% of the total, not 2/3 or even 1/3.
If I had a line that was leaving about 3 megawatts undelivered, I'd want to lay thicker wire; at $.05/KWH, that's about $150/hour it's costing me. That's $3600/day, $25000/week, $1.3 million a year. You can recoup some pretty steep capital costs with that kind of return on investment, especially if you are amortizing over the kind of time-frames typical of a regulated public utility.--
Time is Nature's way of keeping everything from happening at once... the bitch.
Quick recap of Carnot efficiency: Eff = (Thi - Tlo) / Thi. Thi is the temperature at which you put heat into your working fluid (assuming that it is at a constant temperature, which it isn't in any real engine). This is where the internal combustion engine kills the steam engine. It does it because the steam engine has to run its working fluid below the highest working temperature of its parts (the boiler wall is always hotter than the steam). The internal combustion engine produces heat within the working fluid, so the working fluid can be far hotter than any part of the engine. You can easily have combustion temperatures of 3000 F or more in your car, temperatures a steam engine cannot approach.
Large steam turbines get thermal efficiencies in the low 30's. Medium-truck diesel engines commonly break 40% (look at the Cummins data sheets if you don't believe me), large marine diesels hit 50%, and combined-cycle power plants (which use gas turbines - internal combustion engines - as the topping cycle) are up to 60%.
--
Time is Nature's way of keeping everything from happening at once... the bitch.
I collect cars. Work on 'em, fix 'em, break 'em, and fix 'em again. I know the internal combustion engine all too well.
;)
:)
How does this car sound? Well hot DAMN, somebody FINALLY figured out something other than (gasoline, alcohol, nitromethane) to inject. Basically, this is a very interesting system that works. How well does it work? Time will tell.
But you could probably modify any engine in the world to do this.
Instead of creating compression through combustion, it's direct injection of compression, forcing the piston down, thusly turning the engine. The horsepower potenetial is nil, but it's an excellent economy design. And the kicker is that, despite what others have said, unless there is a genuine combustion cycle, there is no emissions outside of what you put in. If you put in clean air, clean air will come out, in this setup. The engine will probably be low maintenance as well - you don't have to worry as much about rings failing from carbon buildup, or piston failure from using too low an octane rating. Although I wonder if using pure O2 instead of air could cause detonation, heehee.
Sounds like the best idea I've seen in a good long while. Now all they have to do is figure out how to do it in a better looking car that's smaller, and I'll buy one!
=RISCy Business
your company here.
your company here.
shelby != ford