Building air pressure scooter?

[boot82050]

Are there people who have build a underwater scooter with air pressure?
I want to build a underwater scooter witch is propelled bij a 15 liter air tank with 300 bar

Has someone got building idea's ie for the transmission to the propellar?

Greetings,
J Bodewitz

 

[mddolson]

I don't recall what the engine type was called in the torpedo community, but I read about them a long time ago in pop mechanics, where they were called a wobble plate
engine.

There are a number of parallel cylinder and a tilted elliptical plate with a track for the rod ends. The rod run around the track and thus move in and out of the cylinders. There's some rotation in there somewhere, but I don't recall the exact way it worked. There are valves in the head to let the high pressure gas in to drove the pistons back, and to let the gas out when the pistons move back into the cylinder.

Mike D

 

[Scuba_Vixen]

That would have been the long skinny ones that looked about like a starter. 3 Double ended pistons (6 altogether) with a warble plate in the middle. I wonder if they'll work bass ackwards?

 

[boot82050]

i thought the easyest way was to use a wheel with blades on it
to propel the propellor.
but i dont'n t have experience with this concept.

j bodewitz

 

[Braunbehrens]

First thing you should do is figure out if there is enough power in the tank to make it worthwhile.

I've been thinking about it, and I don't think there is.

Here is my reasoning:

To propel a diver, the valve would most likely need to be wide open. This means that the tank would empty pretty fast.

For the actual calculation you'd probably need to figure out how much energy is required to prople the diver forward. Then figure out how much energy is present in the tank. You'll probably loose at least 30% of the energy, so that should be factored in.

IF, and it's a big IF, it's possible to make such a contraption, then it would be worthwhile to see if you can collect the gas at the exhaust to use for breathing. For example, instead of dropping the gas to ambient, you could drop it to an intermediate pressure of 100psi above ambient, then use a second stage.

Cool project in any case, I'll be curious to see if it goes anywhere.

 

[boot82050]

thanks for you reply,
I think there is a lot of energy stored in the tank becouse it can go through a brick wall if the valve is hammered of. (some found out by accident).
I thought some people would have already tried this at home.
I am curious to, so I think I am goint to build a prototype.
Greetings,

Justin bodewitz

 

[Braunbehrens]

boot82050 once bubbled...
thanks for you reply,
I think there is a lot of energy stored in the tank becouse it can go through a brick wall if the valve is hammered of. (some found out by accident).
I thought some people would have already tried this at home.
I am curious to, so I think I am goint to build a prototype.
Greetings,

Justin bodewitz

Yes, but that is all the energy released at once, and on the surface.

You could build a setup where the air escaping from the tank valve pushes down on a scale. This would tell you how much force the tank is putting out with the tank valve open.

I'm sure there is a mathematical formula as well, but I don't know what it is.

 

[Braunbehrens]

I did a little more research on the subject.

It looks like the energy from a scuba tank is roughly equivalent to a 24 volt battery producing 15 amps for one hour.

This would probably be enough to drive a scooter.

 

[Munin]

I had an engineer friend who worked it out once. An 80 gave only a few minutes of time, something like 5-10 minutes. It must depend on the drive train design, though, and I don't know what he used for that.

 

[kavka]

Few years ago someone was driving a boat on such engine.Motor boats are in Bled lake forbidden so he was using compresed air. As I know 15l tank was enaugh for 1h. I'll ask for plans.