Multi-Blade Savonius

[Bernd]

Gear up a system is helpfull:
A) to increase the voltage if its to low at a given rpm
b) to get into load beginning at wanted rpm

Gear is not the solution to increase the Ampere, at least not without modifying the stator too when using direct battery load.
If the load beginning is around 3m/s you have found the nearly optimum gearing.
If you increase the gearing more than this, then the turbine gets overloaded and it gives you less amps than before.

Example:
You found that optimal amps are around 1:3 gearing.
Than you can increase the gearing to maybe 1 : 6 and change the stator to give out just the halfe voltage/rpm than before.
This would reduce the inner resistance to 1/4 and will give out more amps i think. (and less waste)
So try to modify or reconnect your stator a way to reduce the output voltage if you use high gearings.

Grüsse

Bernd

[GoVertical]

Hi, thank you for the information. Future changes for this project are to reduce the gearing, increase blade size, and craft new stators. Thanks again and enjoy the day.

[GoVertical]

Greetings, photos of new blades.

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http://www.youtube.com/watch?v=uffHDWlGQ6Y

[GoVertical]

Hi, just complete the road test. Results using three blades, very bad, startup 25 MPH and 1 amp at 40MPH. Results for 6 Blades, about the same as the fin style last tested. Conclusion, the fin or C rotor configuration produced the same results. Style of blade will be based on ease of fabrication because they produce the same results for this size blades. I am primarily interested in produce as many amps as possible at low wind speeds, 10 to 25 MPH. I am reducing belt drive gear ratio, increasing blade length, and replacing stators.

[Ilias]

hi govertical,
nice work. can you close the end from the black blades. so you finish the configuration same C rotor. can you test this?
i am very interestet for the results.
gruß
Ilias
sry for my english

[GoVertical]

Hi, thank you for the suggestion. I finally determined away to fabricate the end caps. I plan on fabricating a much lager C shape for each blade and this time I will include end caps. I will post test results when available. I did find out that bigger is better for my design. I was dealing with a lot of misconceptions when I started this project. Being able to test a working unit has really made me aware of realistic goals. Using this design I plan to make the blades as large as possible, reduce the belt drive ratio to 3:1, and down size the PMA by using a smaller wire gauge in the stator coils. Your English is better than my German. Thanks again and enjoy the day, Comments welcome.

[Bernd]

and down size the PMA by using a smaller wire gauge in the stator coils

Why do you want to do this ? It will increase the inner resistance of your PMA.
For direct battery charging the inner resistance should be as low as possible.

Grüsse

Bernd

[GoVertical]

Hi, most of the time the wind speed for my area is 4.5 ms (10 MPH). Because I have stacked or stratum stators I connect them in parallel and this keeps the internal resistance low. I can also add more stators if required. High wind for my area only happen a few times years. Making a PMA that has a high output at a high wind speed is a waste because most of the time there would be no high wind speed to power it. It makes more sense for me to have very large blades that are geared at 3:1 and have that connected to a smaller PMA that would produce a high current at a lower RPM. That would keep fabrication cost low and I could craft or build more than one. I need to design my stators to have a higher current output at a lower RPM. If anyone has any suggestions please let me know.

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[GoVertical]

Hi, just quick note about a open source VAWT project. Real nice wing design. The site has a lot of usable information and videos. Enjoy the day.

https://sites.google.com/site/veneciam1windturbine/

https://sites.google.com/site/veneciam1windturbine/

[Bernd]

Yes, a very nice site, i like the simple design. Unfortunately until now there are no detail fotos of his blade design.

Grüsse

Bernd