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Hi Chad,

I built a copy of the Wright Brothers' first wind tunnel while at Greenfield Village. Believe it or not, we were able to use a hand-cranked blower and it worked just fine for wind up to about 20 MPH. The tunnel as I recall was about 16 inches square. The prop was a two-blade affair that I picked up from an Ohio company. Check with Thomas Register and look for fans, propeller. If you do use a hand-crank version be sure to incorporate some sort of anti-backfeed ratchet, etc to prevent the fan acting as a flywheel. Gear it to work best with the input shaft turning at about 100 RPM. By the way, this fan drew air through the tunnel and this made the air stream much straighter.

This tunnel used a modern version of the Wrights' balance for wing sections and it was possible to try different cross-sections to show that some worked better for lift, etc. 

I also built a very high-powered wind tunnel years ago at the Boston Museum of Science. This used a very large squirrel cage blower powered by a 10 HP (!) DC motor. This allowed the demonstrator to vary the wind speed to show various effects. 

You might want to get a wind velocity meter and clock the wind speed that works best for your needs. Then it is possible to calculate the size and power of the blower you will need. 

Good luck and let me know how it turns out!

John Bowditch

> ----------
> From: 	Chad Johnson
> @home.ease.lsoft.com.
> 
> 

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