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Wind / Re: H-Darreius wind turbines ( VAWT ) !
« Last post by topspeed on March 01, 2024, 04:54:59 AM »Example message
Bruce- Reply #7 on: February 23, 2024, 10:24:32 AM »] I know from reading a bunch of your posts and answers to other posts, you understand THE DANGERS when doing these sort of tests and I know JW is a steam guru, BUT anyone else reading these needs to watch the video so they are aware of how quickly things can get deadly.
Ya I blocked him from posting for 29 days. Otherwise unrestricted. We will see if he sees the light. I don't care if he comes back.
{2}And although playing with powder fields is great as was thought to me at kindergarten before I was born (yeah we role a little different here on the wrong side of the pond ) I have these sheets of plastic that can show fields in 2 dimensions. visualizing in 3d just means moving the sheet up and down and making a video of it for analysis after the fact.{/2}
I'm pretty sure it's a Nema frame size 132M.
Motor frame sizes lots of times have a letter suffix attached. My 5hp is a 256U
213T is a common one for more modern motors.
I read through this post from the start again. I really love the progression of the thoughts and ideas. In my opinion, it gets better with every new iteration. I think i could pull off the machining on such a magnet rotor with just my lathe and shaper, plus a dividing head which i happen to have.
The magnet cost has become a way bigger issue, and the 3mm thick magnets are extremely helpful to keep that cost down.
Reusing the original stator winding also keeps the cost down, and is a no brainer if it is intact.
My guess is that a complete generator for a 3m diameter turbine could be built for maybe $150 in magnets and whatever you can scrounge a motor for. They are quite often almost free.
I wish I needed another turbine. I would be all over this.
The new chapter 7 now describes a 32-pole generator using the housing and winding of 4-pole asynchronous motor frame size 132M.Adriaan;
132M !? maybe a mistype of AI auto-correct . My best guess is it was meant to be 132mm.
I could be wrong
Very nice update to the chapter otherwise!! I can easily see how the staggered magnets will help with the lowered cogging
Cheers
Bruce S
I'm trying to wrap my head around your thoughts, JW. Are you striving for better english speakers? Because when it comes to actual trial and error projects, that is what drove this place 15 years ago. Your coloring of brandnewb's work as something less is confusing because he has been breaking the project into separate subjects for the purpose of tackling individual issues. I have not seen any of his work to be simple or undisciplined. He is testing using scientific methods. That was how the site has worked all along.
The new chapter 7 now describes a 32-pole generator using the housing and winding of 4-pole asynchronous motor frame size 132M.Adriaan;
I so am hoping that this is just all a misunderstanding of the greatest kind.
It's Ok JW,
I actually kind of like it how you are able to give a new spin to my avatar name from time to time. It signals me that you no longer believe I am an actual newb.
But please do trust that I have no credentials what so ever in this field yet.
Yet rest assured I will have once all is said and done.
Anyway I tried uploading the stacked coils image again for context but this "the path can not be empty" error is still preventing me from doing that
Given I make no secret of also posting elsewhere shall I just share a link to there? But it feels rather disrespectful to divert traffic from this great community to another. So that is why I have not done that yet.
OK JW so it was you.
Sure you can do what ever it is you want. It is your prerogative and you have deserved that!
But one strong mind against another.
You are hurting my cause. and to a smaller extend that of the greater good.
Let me challenge you then in a good way.
I think I can overrule/or at least confirm by now like 70% of statements that are made by people that have already garnered your trust.
I think it would be only fair if we would as a community see how my ideas are either sound or flawed. And then when sound focus on how we can get a setup ready that can demonstrate/debunk said ideas.
You see JW? Our interests are actually aligned. It is just that I made a false start here and you can't seem to let go of that.
I am here to serve the interest of humanity JW. I would really love for your support on that.
And although you have gotten every right without the need for any explanation. I think you should reconsider your decision.
I have watched the video of Topspeed. It is a nice explanation of how such a windmill works. However, there is one substantial mistake. It is said that the vane is in parallel to the wind if the rotor turns out op the wind but this isn't correct. As the rotor has a certain eccentricity e and as the rotor has a certain thrust Ft, the rotor moment Mr = Ft * e. This rotor moment must be in balance with the vane moment Mv around the tower axis. The vane moment is the product of the force on the vane blade Fv and the vane radius rv at the aeodynamic centre of the vane blade. So Mv = Fv * rv. Fv is about linear to the angle of attack alfa in between the vane blade and the wind direction. You only get a certain Fv if the vane blade makes a certain angle alfa with the wind direction. So the vane blade is never in parallel to the wind direction for stationairy conditions. The angle alfa depends on the vane geometry and the wind speed. The higher the wind speed, the smaller the angle. The vane moment due to the aerodynamic force on the vane blade around the vane axis must also be in balance with the spring moment Ms around the vane axis.
This safety system is called the ecliptic safety system and more information about it is given in my public report KD 409. I have used a torsion spring around the vane axis because the spring moment of a torsion spring increases only a little for an increasing angle of rotation around the vane axis. The moment of a tension spring varies a lot because the distance of the heart of the spring and the heart of the vane axis is very dependent of the angle of rotation of the vane arm. I have chosen that the tower axis coincides with the vane axis because this simplifies the moment equations a lot.
I've been following your posts for sometime Branubie (if you spelled it like that it would be cool). you mentioned you would like to see a magnetic field. there's a way to do this its taught to all 6th graders in school.
Take your magnet set it on a wood table. put a piece of notebook paper over it (try to make it flat and level) then take some iron filings and sprinkle them on the paper. there you go, you will see the magnetic fieldlines.
JW