Hello!
I come back talking about my little turbine:
I ran the alternator this afternoon. it provides a lot of current (I did a test on a 75w load) on the other hand it is very old and mostly worn. It comes from a 2cv.
So I did some calculations with an alternator efficiency of 0,4 after what I read here and there and after a review (change the bearings ...)
(when I am told in class that a synchronous is in the 0,95 ... well, it's not the same powers too.).
I work on a useful power of 50W, to recharge my battery when I am not using it.
With a home-made pinion-chain reducer which I estimate at 0,6 (friction bearings included) I arrive with a theoretical output of my installation at ... 0,24. Nothing to get up in the morning.
I took again the calculations of Christophe (see in this subject) and with a wheel of the same diameter and a speed of 5km / h, I must hold a submerged surface of 300cm² ... for 208W approximately of energy.
The solution I am considering: 3 paddle wheels of 20cm with 10 * 10 submerged surface. All on the same axis: a large steel bar very heavy to have an inertia effect. supported by rolling bearings on each side.
The system must therefore be started manually but its not a problem.
What do you think?
Good night
Bob
PS: If you are interested, I will try to show you the progress of my work. But since I want it to work for the summer, I'm not in a rush.