Thanks for the insights.
It appears that this isn't be the way to go after all.
I was also considering compressed air, but I have no idea how long a bottle (of say one liter) will last. It won't be feasible to haul around 20 pounds of air if it will only last one hour :-).
However, great idea...
It's a bladeless centrifugal flow turbine expander, using the boundary layer effect.
It's on wikipedia: http://en.wikipedia.org/wiki/Tesla_turbine
It doesn't need specialized tools/materials which makes it easy to build yourself using old hard drives for example.
(see...
Hi geniuses,
I have a question about a Tesla turbine.
I'm brainstorming about using a small one as a leightweight "engine" on a kayak, using the flow of the water as energy source.
First of all, I do realize that this won't run on its own in a perpetual motion style.
But my question is...