Motorcycle powered by air..interesting

http://www.fastcoexist.com/1680821/...wered-by-nothing-but-air?utm_source=twitter#1

Propelled by compressed air, the O2 Pursuit can go 100 kilometers on a single tank, and up to 140 kilometers per hour (87 mph), according to Dean Benstead, the graduate of RMIT University, in Melbourne, who designed it.

Interesting. Any info available on weight and power delivery?

edit: "Less than 100kg", and "Constant high torque"

wonder how high?

Probably all downhill.

Hmmm. Sounds like it was designed to run on hot air... Plenty of hot air.

--Bill

Perfect Rally Bike!

I like it. On days I work at the bike shop one tank would get me there and back.

What's max psi of the average Scuba tank?

Compressed air is horribly inefficient.

We had a guy years ago in Joplin that stuck the Bush 1 administration for many $$$ on his air car. Used to see the slow turds around here, out of air on occasion. The guy is a shyster.

Rod

I believe most tanks come in the 3000 or 4500 psi variety.

I think I'll start building superchargers for gas station compressors. The safety factor of the storage tanks should cover the pressure, right?

Oops, then they'd need bigger motors. OK, no problem, big stuff is readily available. Um, wiring. No need to run bigger wire, they can just raise the voltage for the bigger motors. Let's see, standard is probably 240V 3 phase, and 4160v should be on the poles. That should be able to handle motors up to 1,000 HP or more. Hope their wire insulation if nice and thick.

No need for 13.8kv unless it's a real big station. :huh

I hate when people make claims like this. It's not powered by air. Most likely it's powered by a fossil fuel - just like everything else.


Compressed air is just energy storage. Terribly inefficiency energy storage at that. I don't know who filled his scuba tank, but I'm guessing they did it with a compressor that either runs on gasoline or deisel or it plugs into the wall where it gets electricity from a coal powered station.

it's not without it's advantages though. Compressed air fills much quicker than you can charge a battery. So that's something. I don't know if there's any weight savings as i suspect a tank capable of holding 4000 psi is going to weigh as much as a comparable lithium battery.

Note that, like an electric or a hydrogen fuel cell, the compressed air tank is not fuel, but only a storage of energy. The bike will actually be powered by coal, or nuclear, or hydroelectric, or whatever the local electricity is generated by.

It does look like an interesting idea, but I'm not sure about the safety aspect. You've got to handle compressed air tanks with due care; if you bust off the nozzle in a fall, it becomes a missile. Seems a sketchy idea on a dirtbike.

That's probably going to depend a lot on how much pressure is in the tank. Like an electric, it'll have max torque right from zero, and be pretty exciting that way. But much like your old CO2 pellet gun, it'll get weaker each pass and fizzle out.

PhilB

That reminds me, from where did the common term "petered out" derive?:huh

it's inefficient, but it's also lightweight as far as energy storage goes.

being lighter means you need less of the stored energy to transport the storage method's own mass, so the system efficiency is not lower to the same degree that the energy recovery factor is lower.

Also, pneumatics are simple to manufacture and inexpensive, and don't use much in the way of exotic materials.

I'm sure there are some applications where this type of thing makes sense.

Not necessarily. If it is set up to feed air to the motor via a two-stage system, then there would be a first stage valve that reduces the pressure from the tank to the feeder line to a maximum value, then a second stage valve that reduces the pressure again to the feed into the engine.

Assuming for the sake of argument that the engine runs with a 10:1 compression ratio, then at sea level, the second stage regulator valve would need to deliver about 140 PSI to the engine. Until the tank pressure dropped to below 140 PSI, the feed would be at a constant pressure, due to the regulator valves stepping down the pressure, much like an electrical transformer.

Edit: now that I think about it, because this engine is not using IC to generate pressure, the sea level thing does not apply. You would merely need to regulate the air pressure down to whatever the engine is designed to handle.

Scuba Tanks are DOT regulated, which would make them easier to use, but yes, they're heavy. Scale up a large carbon fiber tank from a paint ball gun and the weight would be MUCH lower, but, much more prone to damage and not DOT regulated (as far as I know) which would make them harder to use. An 88ci CF tank at 4500 psi weighs about 12lbs. If CF tanks ever make it to scuba I'll be in heaven.

Actually, the Carbon Fiber over-wrap tanks are pretty tough, all things considered. Not that I'd want to have a dirt bike crash full force right on the tank, but I wouldn't want that to happen to a steel tank, either.

That's when the pressure exiting the new hole (from the missing valve) only has to push the 10 or so pounds that the tank weighs.

Attach that tank securely to a 200 pound plus dirt bike and I don't think the pressure exiting the hole in the tank is going to be shooting the crashed dirt bike around like a missile...

Could be wrong, just guessing. 200 pound dirt bike is 20 times the weight of the cylinder that the exiting pressure has to try and muscle around!

Depends on how securely the tank is mounted. It would be kinda cool if they were removable so you could swap them out.

I'm always skeptical about things like this. These guys should know exactly how much torque and power this thing produces, but they won't say the numbers. Why?

It just makes me think the whole thing is a fraud.

Not a diver- but wouldn't that just mean you'd have to wear more weights?