Bird Physics

J

Jug

Hello! New here. Interested in the geometry of the V formation by migrating birds. The apparent physics of the thing is that the displacement of air caused by the lead birds hepls to pull along the more spent birds at the rear of the formation - thus creating an energy flow. As an energy resources consultant I consider the geomatry of the formation as might relate to an angle of incidence relevant to other means of energy production.

Any bird ladies and gentlemen here?

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Zhou Yu

I don't really know much about birds however I may be able shed some light on the "apparent physics" that pulls along the more spent birds.

The same principle applies when you are going canoeing and a large boat goes past. Now the large boat creates a wave as it pushes through the water, and if you can keep up with the larger boat ( assuming it isn't going too fast ) then you can go just in front of the wave and it will help push you along.

The same principle applies to the birds, the lead bird ( the one at the front ) has to push through the air. In doing this he creates a slight increase in the air pressure in front of his wings.

So the other more spent birds can either fly just in front of this pressure wave and be pushed by it, or more likely in regards to what you are saying fly slightly behind it.

Now because there is an increase in pressure, there is also a decrease in pressure just behind it. A little like when a bus goes past and the vacuum causes you to almost lose your hat if you are to close.

It is most likely that the more spent birds use this vacuum just behind the pressure wave to help pull them along.

russ_watters

Mentor
Wingtip vortices.

Air under a wing is at a higher pressure than air over a wing. This air 'spills out' from the lower surface toward the upper surface, creating a vortex which vastly reduces lift. Flying just behind and outside the bird in front means the vortex coming off of its wing will hit your wing on the upswing of the vortex, increasing your lift by disrupting your own vortex.

J

Jug

Thanks to you both - good information. Will study the vortex system closer and attempt to convert it to a water system using the V formation as giving an angle of incidence.

LURCH

Originally posted by Jug
Thanks to you both - good information. Will study the vortex system closer and attempt to convert it to a water system using the V formation as giving an angle of incidence.
Just a note; The two phenomena are so similar that wingtip vortices are also reffered to as "wake turbulence". As the birds travell along, the lead bird will eventually pull out of his position and drift back to the last position where progress is easiest. From there, he will work his way forward (as others take lead and then fall in behind) untill he is once again in lead, but more rested.

J

Jug

Yes, Lurch, that is the idea of it sure nuff - an energy transfer system!

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