Monumental Windsculpture Engineering Question

[Ralfonso]

Good morning,
I am a designer of large to monumental kinetic, mostly wind-driven, public sculptures.

My newest design calls for square discs to rotate in the wind - see encl.

My 3 questions are:

1. What is the best shape of the horizontal cutout of the sides of each square disc, to give max. torque, - a triangle or a square cut out?
2. How would I go about measuring the rotational torque and speed of the discs - is there a simple program for this?
3. Is there anyone out there I can hire to help with these wind-resistance calculations?

Thanks so much for your help!

Ralfonso

http://www.ralfonso.com

 

[RPstress]

Looks very interesting, but
1. Sketch(es) needed. I don't understand what part of the geometry the question is about.

 

[Ralfonso]

Thank you for your time and interest!

I encl. a rendering that will hopefully help with 1.

Any advice for 2. and 3. would be most welcome

Cheerio, Ralfonso

 

[Sparweb]

Hard to be sure... Depends on what you want the sculpture to do. Spin slowly or spin quickly?
Will people approach the structure? Will they be able to turn parts by hand?
Presumably an art installation should be visible if not accessible to the public (by definition... of course).
When it rains, is it acceptable to have sheets of water flung at people nearby?
How big is the structure? Will people be able to climb on it? If they can, they will.
Especially if the sculpture is installed near an establishment that serves alcohol...

You should just try making one or two out of cardboard and find out for yourself how it behaves.
You'll probably find that it doesn't spin very much at all unless the axle bearing is in perfect condition.
Maintenance may be required to ensure the the sculpture is still able to spin after a year or two.

I know - I sound like a total kill-joy.
You should expect this kind of negative what-if thinking when you post on an engineering forum!

STF

 

[rb1957]

I'm not really seeing these turn that much ... maybe if you filled the space between the plates with 4 semi-circles, more like an anemometer, see attached.

someone in CFD would be able to help.

Making models is a good way to prove the concept.

another day in paradise, or is paradise one day closer ?

 

[IRstuff]

One obvious incarnation might be squaring up a squirrel cage fan rotor. The flat parts on the sides of the current version are probably going to fight you to some degree.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[Ralfonso]

Thank you all for taking your time and for your good input.
I will build some models to test the concept...

What kind of engineer or who should I specifically turn to in re. to wind sensitivity of large shapes and how to optimize them?

Cheerio for now - Ralfonso

 

[Sparweb]

I doubt there's a "perfect" engineer for your project, since it combines mechanical and civil engineering, and must be approved for installation by any city or town administration if on public land.
Is this project funded already?

STF