Create a Dynamic Wind Sculpture: Tips and Tricks for Instability and Movement

[spindog]

I am trying to create a wind sculpture and I could use some help. The sculpture will have 3 points of rotation all driven by the wind. Visualize the letter "Y" and you will have the basic idea. The base has bearings allowing rotation as do both of the arms. My prototype model works to some degree but stabilizes or "weather-vanes". It moves only when the wind direction changes. This is not what I wanted. What I wanted was for it to tumble randomly about. I am remembering my youth rocket building days. There I had to insure that the center of pressure was behind or lower on the rocket than the center of gravity or it would not fly straight. I'm wondering if making the center of gravity and the center of pressure the same spot on my wind sculpture will create the desired instability I'm after. I have no real aerodynamic or physics training/knowledge to speak of. So I'm going to need a laymen description if possible. Thank you for any direction or help you might be able to provide.

 

[CFDFEAGURU]

This probably doesn't help you much unless you live in Pittsburgh, but near the back entrance to the Carnegie Museum of Natural History and the Carnegie Library, there is complete full scale wind model that does just what you are after.

Thanks
Matt

 

[spindog]

Thanks DFDFEAGURU for the quick reply. I'm always interested in hearing about this sort of thing. Do you know the name of the artist? Or is there a link that might have a photo?

 

[turbo]

If you want a sculpture that moves a lot, they you will have to avoid weather-vaning. Don't put wind-catching elements too far from a point of rotation unless they are balanced by other elements of roughly equal drag. Something sleek and streamlined is only going to move around when wind velocity and direction change dramatically. You want to make something that is very balanced, so that slight changes in wind direction and velocity will shake it up. Probably the best that you can hope for is to design one of the top ends of the "Y" so that it is very unstable and drives into oscillation easily. Then it should be easier to figure out what your other wind-catchers will do when they are forced into new directions due to the oscillations of the most balanced and unstable element.

 

[negitron]

If you search YouTube for "wind sculpture" there are many videos of various designs you can watch for ideas.

 

[CFDFEAGURU]

I haven't been able to find a picture, but I live close enought to go and take a few for you.

Let me know if you need me to.

Thanks
Matt

 

[CFDFEAGURU]

Spindog,

How is this project working out for you?

Is it complete yet?

Thanks
Matt