Wind Tunnel for Birds 126
bgood writes "'What, a swallow, carrying a coconut? ...' The Department of Animal Ecology at the University of Lund in Sweden uses a modern low-speed wind tunnel specially crafted for bird experiments. The birds are trained to fly in the 'test-section' and the tunnel can be tilted up or down to simulate ascent and descent. This link contains plenty of detail, complete with bird pictures. For those of you who yearn to build your own (non-bird-compliant) wind tunnel, you can find instructions in this Scientific American article."
007 Bird Agent (Score:3, Informative)
Re:Smart Birds? (Score:2, Informative)
Only if the bird flies ``downhill''. A quote from the page:
Re:Why Tilt the Whole Thing? (Score:3, Informative)
So, changing wind direction may actually make it a much more complicated environment w.r.t the bird.
I've seen worse (Score:2, Informative)
Re:Why Tilt the Whole Thing? (Score:1, Informative)
Consider the following:
1) Tilting the tunnel at 45 degrees
2) Generating wind at a 45 degree angle within the tunnel using a moveable source.
There are 2 frames of reference - inside the tunnel and outside the tunnel.
The angle that the wind is blowing is constant w.r.t the outside of the tunnel. Therefore in both cases the angle between gravity and the wind is the same. The angle between the wind and the tunnel, however, is different. I suspect that this may be the main rational between the approach to changing the angle of attack.
(Or, I could be on crack.
Re:What about the noise? (Score:3, Informative)
Uhm.. Not all tunnels are loud. I imagine this tunnel is only running at 10-20mph.. At those speeds the aeroaccoustic noise should be very minimal (Noise is proportional to Velocity^4).. Assuming the motor is sized correctly, well balanced, and turning an aerodynamically clean fan, the noise levels should be very small in the test section..
I'm actually surprised they decided to use a closed loop facility for a study like this. The cost of a closed loop facility is roughly 2.5 times the cost of an open loop facility (all those turning vanes should be airfoils) and there are air exchange issues to deal with..
interesting project though.
Link to an article (Score:2, Informative)