Powered Surfboard: Mounting HPA Tank & Turbo Tunnel Fin

[malonui]

Hi out there, here is my question to those in the know... I want to mount a HPA High Pressure Air tank on the deck of a surfboard and by way of a regulator and inline control valve direct the air through a ducted fan prop and out near the tail of the board hopefully giving enough thrust to power assist paddling. The tank is light ..2.5 lbs and holds 68 C.I at 4500 PSI. The outlet is directed through a Turbo Tunnel fin which is a standard longboard fin with a a cowling type unit integrated into the design. The ID of the Turbo Tunnel is around 40mm. This idea is not to expect power boat performance however would like to think small high pressure bursts would assist a surfer in getting out in difficult sections. Any suggestions to achieve the best result given the info provided would be greatly appreciated

 

[billy_joule]

Any suggestions to achieve the best result given the info provided would be greatly appreciated

I'd do some basic research to check feasibility, you need answers to theses sorts of questions:

At what speed/s will it be used?
What is the drag force at theses speed/s?
What acceleration do you want?
What is the thrust force required for this acceleration?
What is the air mass flow rate for this acceleration?

Off the top of my head I would guess your energy density is far to low for a usable device (unless a few seconds of thrust per fill is acceptable) but I'd like to be proved wrong, it's an interesting idea.

 

[montoyas7940]

Would you use the air to provide reaction force or were you planning to drive a small air motor?

 

[Dnomyar]

Mythbusters tried compressed air tanks on a speedboat - not successfull

http://mythbustersresults.com/episode63