windgen.org vawt discussion

So much discussion about this mysterious X-rotor.
Well,Steve, I appreciate your virtual turbines,but if they're secret too,it becomes annoying.

cheers,
stonebrain

Standing by for the details

Thanks,

Turtle

keithturtle wrote:

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sjh7132 wrote:

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unless someone offers me a million dollars for it first. )  :-)

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SO much for open source.  Now I'm ticked

Turtle, slow

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Don't worry it will become public domain.  It's way too simple for anyone to pay for.  Plus we don't even know that it works yet.

 

electrondady1 wrote:

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....

so he could have some positive support as he made the switch to vertical axis.

perhaps it was not your intention but it struck me that you kind of
pounced on this guy in spite of the fact that he is building his very
first mill.

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It was not my intent to pounce on him.  (Sorry d3lilley)

But in fairness he was asking for advice on the alt, wasn't he?  He had mentioned if it didn't work out like he though he was going to built a turbine with a larger diameter.  He described a design like Ed's alt, but when I asked for some of the necessary info, it turned out his magnets were much smaller. (thick but small).

I believe I made a reasonable, and probably optimistic guess at the flux between magnets and concluded the voltage was going to be too low.    We had the wire gauge, number of turns, magnet size, and rotor diameter.  I didn't have stator thickness, but I knew the minimum from wire gauge and turns and space between magnets.  If the stator is thicker than I thought, things will only be worse.

I don't know about you guys, but if I was about to spend a good chunk of money to build a turbine, and someone KNEW that it wasn't going to work and didn't tell me.  I'd be pretty mad.

I'll agree that the air flow simulations are hit and miss.  But there is nothing mysterious about knowing what an alternator can / will do.  The only hard part is the magnetic flux and you can make an intelligent estimate at that.  I believe my results are much better than using ESP or sacrificing an animal.  The other question is what will the Lenz blade do.  We know it runs at a TSR between .6 and 1.0, with 0.6 - 0.7 being best.  I used his estimated wind speeds to figure out what RPMS he would see.

So given my warning he has a few options.
1) Ignore me.
2) Plan on using a voltage doubler or a 6v battery.
3) Use a 12v battery and charge with just the peak of the sine wave which is 1.4 * the RMS value.  At 250 RPMs he'd start to charge.
4) Make a smaller diameter Lenz (opposite of his original plan)
5) Use a different type blade.
6) Build the HAWT

If he chooses #1, and I'm wrong, I hope he will report back so I can figure out where my calculations went wrong.  I'm depending on that same spread sheet for my alt design.

I sorry again if I was harsh.  I thought I was answering a direct question and I was just putting out the numbers which I considered to be pretty reliable.  I probably won't do that in the future.  This community is more nuts and bolts and prefers to build things and then make them work.  I'm the opposite, but that's a byproduct of my job.  When you send things into space, you don't get a second chance.

 

sjh7132 wrote:

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Sorry, bad mood yesterday and one post kind of ticked me off.

I'll just leave this teaser and go away and built my turbine:

Turbine X
Peak simulated efficiency (TSR 1.0) 59%  (The Lenz simulated at 40%)
Power band from TSR 0.6 to TSR 1.7 of 40% efficiency or more. (simulated)
Easy shaped wings.
100% self starting

You'll see it when I can show a real one works. (unless someone offers me a million dollars for it first. )  :-)

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I can hardly wait.  If you want to patent it, make sure you get the paperwork going before you disclose it publicly.  Out of curiosity, did you invent it or did your genetic algorithm find it?

 

Steve



first . i want to say i think your a brilliant fellow.



your knowledge of electronics and computer programming is impressive to say the least.

you are a real asset to the forum.



i personally think that you post way too much about your simulations and
not enough about the machines they lead you to construct.

when you posted a list of the machines you have experimented with i was surprised at the number of of them .

and taken aback, because i could not recall you ever mentioning them.

other than the jelly fish design.

and i could not recall any postings as to it's performance.

or any follow up posting about it.



earlier this week at the other power forum i invited d3lilley to check out

the windgen site.

so he could have some positive support as he made the switch to vertical axis.

perhaps it was not your intention but it struck me that you kind of
pounced on this guy in spite of the fact that he is building his very
first mill.



there are so many variations present  from any  known alternator i questioned the relevancy of your findings 


that was the basis of my "goat sacrifice" remark.
i noticed you have removed all the graphs and  such that you posted
about his project ,




so, when  you posted an entirely new simulation project  that was going to beat ed's mill and  the betz limit  i posted my

"another simulation steve ?"remark.
it was my intention to challenge you and motivate you to actually build the thing



i am sincere in wishing you every success and i hope the new wing
profile will change not only your financial situation but the world as
we know it.

regards, Shawn

sjh7132 wrote:

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unless someone offers me a million dollars for it first. )  :-)

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SO much for open source.  Now I'm ticked

Turtle, slow

 

Sorry, bad mood yesterday and one post kind of ticked me off.

I'll just leave this teaser and go away and built my turbine:

Turbine X
Peak simulated efficiency (TSR 1.0) 59%  (The Lenz simulated at 40%)
Power band from TSR 0.6 to TSR 1.7 of 40% efficiency or more. (simulated)
Easy shaped wings.
100% self starting

You'll see it when I can show a real one works. (unless someone offers me a million dollars for it first. )  :-)

Same here Steve ,you have good posts!  I don't think anyone intended to offend you.

Hey Steve,

I always enjoy reading your posts and I'm sure everyone else does.  I have learned a great deal.

Jerry

Steve,
 Failing is fun so don't be paranoid if your first turbine fails and start simulating what might/could be/should be/ must be/it really is about real world testing.

 I remember dancin around the yard after several failed attempts back in the day and watchin the neighbors peek through the trees thinkin i was goin crazy.LOL

 Remember to have fun first and don't drain yourself with perfection.No matter what you build the thought that if i did this did that will always be in your head.

 I wish you luck but to me any vawt that has to be pushed along via open cup is gonna be weak unless sized larger.Thats simple the lift gained is the power produced.

 Hang in there and keep chuggin.

 Mark

Results of the standard NACA 0018 -- 0021 Profiles seem to be very interesting, because they are often used at VAWTs.
And i wonder why they are are not working well, because of they are so often used for VAWts.

I think for most of us it would be interesting to see an compare between a NACA 00xx and for example the Lenz 2 Design.

Bernd

-- Edited by Bernd on Friday 5th of March 2010 01:32:12 AM

Bernd wrote:

Don't be hurt, but i have the feeling that mostly all blade designs show good results in your simulation tool ?

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No that's not true.  For every 10 I run, you guys don't see the 9 that stink.  Even the NACA0020 foil didn't work very well.

But I think for the time being, I'm going to take this post down, until I get time to build it.

Hello steve
for me it seems that every time you do a simulation two points appear.
The first is that the simulated turbine has a very good cp, sometime with inexplicable peaks.
The second is that is shows a higher usable tsr than in reallity.

If i look at your results, using my own "filter", which takes attention to this two points, its still good.
Don't be hurt, but i have the feeling that mostly all blade designs show good results in your simulation tool ?

I'm very interested in first time reallity results.

Bernd

Post removed


-- Edited by sjh7132 on Thursday 4th of March 2010 11:46:17 PM