pneumatic waterjet dpv

[Linus_86]

Hello!

I have seen the generall "diver propulsion vehicle" wich looks like a fat batterypowered torpedo and appears to be rather slow and clumsy. I wonder if there is any high prestanda alternative to this type of UV-scooter

my thought about it is that using a standard scuba tank to propell water through a nozzle (like its done in waterjet boats) would give impressive power since it is possible to release the energy much faster than it is possible to drain the power in a battery. a calculation I found on the net gave that the power in a 300 bar 12 litre scuba tank would give you about 5 hp in 7 minutes. if you use it up in 3.5 minutes you would then get 10 hp and so further.

if you released all the energy instantly it would give you the power in a handgrenade times 3 equal to about 600 kilogram TNT...

this gives that releasing the pressure fast into a watertank to propel water through a nozzle would give you rocket performance! while still be able to save the energy and podle around slow using the regulator

If you search the net for "water rocket" you will find pictures and videos about the principle of it.

my question:

have anything like this been developed?
is there any uv scooters using a scuba tank as energysource?

Im not an active scuba diver and havent tried any uv scooter "live" my opinions is grounded on what I have read. correct me if Im wrong

any thoughts about this is very welcome!

best regards/ Linus

 

[gregor1234]

You yourself have indicated exactly why such a device is considered impractical.. To get the sort of power that you need to move a diver throught the water at any reasonable speed, you end up using all the pressure in the tank very rapidly. Besides, moving at speeds greater that 2-3 knots would put too much strain in the diver and his equipment. His mask would fall off and it would be too hard to hold on to the propulsion device.

To this add the fact that you also have to move not only the diver and his equipment but also the heavy pressure tank supplying the compressed air. And the diver who is already tired of hauling heavy tanks containing his breathing air from his car to the boat or out onto the beach is not going to want to haul another cylinder full of air for his propulsion device.

On the other hand you could fill that tank with hydrazine and LOX and light'er up. Now that'd be a ride.

 

[Gary D.]

There isn't much out there today better than a prop or screw. A jet drive is not a good use of power as a lot is waisted. tay with a prop.

Gary D.