MJenkinson said:
Just seen this on facepage, god knows whether it's real or not (or in production) but if the claims are true it woudl be good for you expedition types maybe?
https://www.facebook.com/TechExplorers/videos/595445817299848/
This thing looks shite, the simple reason being that you will really struggle to get any meaningful power out of it. The swept area of the blades is tiny and will not manage to harvest barely any of the waters power.
The maths is really quite simple
P= ? x ? x Q x g x h
where
P is power in watts
? is the dimensionless efficiency of the turbine
? is the density of water in kilograms per cubic metre
Q is the flow in cubic metres per second
g is the acceleration due to gravity
h is the height difference between inlet and outlet in metres
so for this, lets be optimistic and say its about 70% efficient.
the flow Q is the tricky one to determine, again lets be optimistic - 50 litres a second or 0.050 Cumecs.
and the real flaw on the plan, the height drop - 1 cm? In a levelish river, the water is not really falling at any gradient.
so we've got 0.7 x 1000 x 0.050 x 9.81 x 0.01
34 Watts ... Hmmm - a person pedaling a bike will give out about 100W
Leclused said:
This is more like it! - You could realistically set this up to generate 100W of constant output. A 15m or more drop, potentially much more if in a vertical cave entrance could net you some proper power.