Calculating Vertical Axial Flux Alternator Output

[Dannyo1]

Could someone please explain the calculations for determining the output from various sizes of vertical axial flux alternators?
Cut in torque specs would also be great to have.

I've done some Google searches but thought you guys may be able to explain it a little better or have some great links.

Thanks, Danny

[ChrisOlson]

You may have to clarify your question a bit because I'm not quite sure what you're asking.  Determining output for a vertical shaft generator is no different than for a horizontal shaft.  And cut-in has more to do with speed than torque.
--
Chris

[tecker]

It's not the size really . The RPM you settle in on is 100 to 200 RPM normal operation.  Drag or lift you still live with that RPM range in normal conditions 10 to 30 Knots . 

[DanB]

It's not the size really . The RPM you settle in on is 100 to 200 RPM normal operation.  Drag or lift you still live with that RPM range in normal conditions 10 to 30 Knots . 

Tecker - maybe he's provided more info somewhere that I've missed.  But if not, the rpm range could vary greatly.  A savonius (I assume hes talking vertical axis wind turbine) turbine will want to run at a TSR somewhere around .6 - .7 I expect, a darrieus perhaps a TSR of 3.  And without knowing the diameter of the machine...  then the rpm could be about anywhere.  Drag, or lift = completely different rpm ranges in 'normal conditions'.

[scoraigwind]

There is an explanation of how to design an axial flux alternator on page 54 of my Recipe book.  It's a bit longer than would easily fit in a post on this board, but if anyone has any questions about it I can answer them by email or on this board (if I do happen to check the board at the time).  I spend a lot of time answering questions about axial fllux alternator design in fact.  But it's great if people take the trouble to buy and read the plans first.

[tecker]

OK I was thinking Vawts with Axial alternators

[kcchow]

hi Scoraigwind,

Anywhere i can review your recipe book?

[scoraigwind]

You can build an axial flux alternator for a VAWT and I have designed a lot of them for misguided VAWT enthusiasts.  All I needed to know was power and rpm stuff just like with a HAWT.

I am not sure what you mean by review the recipe book.  It's not expensive to buy one.  And there are some details here.
http://www.scoraigwind.com/axialplans/recipecontents.htm

And you can get some good glimpses of the detail on this page as well:
http://www.scoraigwind.com/axialplans/recipe%20update/index.htm

I hope this helps you get an idea of what I have to offer.  I spend a lot of time giving free advice and I love doing it, but I also rely on people buying books from time to time to keep me fed while I sit and answer all of their email questions.

[DanB]

I'll chime in and give it an excellent review!  It is the only place I know of where you'll find  -all in one place, good information, formulas, and techniques to manufacture alternators and wind turbines of whatever size you like (so long as it's not too big).

It cannot be reviewed online anywhere, but it's money very well spent and a 'must have' for anybody spending with this stuff.

thanks Hugh!

[florin.tanasa]

Hi I'm new on forum but read it for some years.
I have tried to make a calculation sheet for calculating the axial flux generator.
http://sites.google.com/site/florintanasa/fisa_calcul
I waiting for feed back about the accuracy of calculations.
Sorry for my English, but I'm from Romania.