A car running on compressed air

[McVenco]

Found this a while ago:

http://www.theaircar.com

It almost sounds too good to be true, but reading through the website it could be a possible top-seller. Especially in the big cities I think.

I wouldn't buy one since I drive too much for my work to make this a good alternative, but if I live in a city with everything close by, I'd might buy one if the price was right (and when it's available of course).
Would you?

[X-ray]

Rumour had it that Karl once had a prototype vehicle that was propelled by compressed gases that were the product of a very strong curry. Alas, there was a defect in the 'gas-line' and a wayward cigarette butt from a passer-by ignited the whole gubbins.
It was then that he changed his name to Karlos  :-P

[PMC]

Actually x-ray...

You may be onto something there...  Sprouts, preferably curried could be used to generate an alternative source of high octane biogas, which could then be pumped directly into a combustion chamber and instant propulsion!

[Karlos]

...but for a brief moment there was a glorius 8g acceleration, straight upwards :lol:

[Speelgoedmannetje]

X-ray wrote:
Rumour had it that Karl once had a prototype vehicle that was propelled by compressed gases that were the product of a very strong curry. Alas, there was a defect in the 'gas-line' and a wayward cigarette butt from a passer-by ignited the whole gubbins.
It was then that he changed his name to Karlos  :-P

If that vehicle was a SUV, it could climb the mount Everest?

[odin]

But...good gods, would you want to actually drive *this* turd:



That's as pretty as a freshly clipped toenail!

Also the energy has to come from somewhere, so it'll still use  electricity which is generated with fossil fuels or by nukeplants.

[NoFastMem]

Exactly. What's powering your compressor?

We already have electric cars, that's not where the innovation needs to be made.

[KThunder]

lead acid batteries are about 75% efficient and very heavy
nicads are lighter but still can fold much

if compressed air can store as much energy and be lighter this could be a good tech possibility

a couple years ago i hooked an air hose from my garage air compressor to a weed wacker engine (small 2 stroke) and gave it a spin and it took off and that was at 140 psi (10bar?)

i wonder how my motorcycle would run with a scuba tank supplying air

[Karlos]

Compressed air isn't that lightweight, especially when you are talking about 300 bar. That's 300x denser than usual (roughly 315 kg/m^3 at 20 Celcius), even before you get to the weight of the material needed to contian it. However, it said they used a form of carbon fibre for that.

-edit-

It says on the site (under the FAQ) that the car holds 90 m^3 (at 300bar), so that's ~92kg just for the compressed air itself. I think standard batteries are a good bit lighter.

On the plus side, it get's lighter as you expend it :-D

[KThunder]

you can also recharge it alot quicker.
as air heats as it is compressed the temps would be the limiting factor although carbon fiber tanks would be ok as long as the plastic liner can take it.

when i was a kid we had these toy cars that had a tank on them that you could use a little hand pump to fill, those things would move heck and gone faster than any battery powered rc as fast as a gas powered one but of course with just a hand pump they would run out of air pretty quickly

[KThunder]

i just did some searching to find battery pack weights for different vehicles.

most hybrids have a pack weight anywhere from 20-30kg up to around 100kg

fully electric cars have packs weighing anywhere from 100 to 500kg

fully electric cars with a range of 200km would have a pack closer to the 500kg range and be very slow to accelerate.

[Karlos]

fully electric cars with a range of 200km would have a pack closer to the 500kg range and be very slow to accelerate.

You obviously haven't seen the Tesla Roadster ;-)

That thing delivers more torque at 8000 rpm than most petrol engines do immediately after starting...

0-60 in about 4-5 seconds acceleration enough for you?

[PMC]

Karlos wrote:

That thing delivers more torque at 8000 rpm than most petrol engines do immediately after starting...

Do you mean more torque from low revs than most petrol engines at 8000rpm?  That would make more sense...

Electric motors can produce massive torque very low down in their rev range (why they tend to make excellent powerplants for locomotives for example) but will also rev very highly indeed because there is no reciprocating mass unlike in a petrol engine - unless of course you're talking about a Wankel (fnar) which has very reciprocating mass but low down torque is greatly reduced and usually requires a turbo charger to enhance the torque.

[Karlos]

I meant it delivers more torque at 8000 rpm that a typical petrol engine does at much lower rpm, or indeed at any rpm, if the following is to be believed:



See for yourself

[KThunder]

Karlos wrote:


You obviously haven't seen the Tesla Roadster ;-)

That thing delivers more torque at 8000 rpm than most petrol engines do immediately after starting...

0-60 in about 4-5 seconds acceleration enough for you?

i obviously have seen the tesla
it also has a lithium battery (very expensive)
its also a two seater right?

my comment wasnt that electric motors arent powerfull but that usually to give them decent range the pack has to be so big they cant accelerate very quickly. simple fact of physics electric cars wont acclerate or handle well when the battery weighs almost as much as the rest of the car

btw they dont state it on the site but the 200 mile range is probably at 40 to 45 mph