How does air stick to a wing

Bsmiller05

Bsmiller05

Well-Known Member
What's the best/common way to describe the action of airflow sticking to the upper surface of a wing? I've been reading about coanda/magnus/boundary layer/surface tension, but it all start running together.

Any help would be great!
 
Personally I use super glue or double sided tape to make sure it sticks. The super glue makes a smoother surface though;)
 
It is a fluid and flows around the airfoil. The molecules near the airfoil impact it and slow down.

This has an easy explaination:

http://www.grc.nasa.gov/WWW/k-12/airplane/boundlay.html


As the fluid moves past the object, the molecules right next to the surface stick to the surface. The molecules just above the surface are slowed down in their collisions with the molecules sticking to the surface. These molecules in turn slow down the flow just above them. The farther one moves away from the surface, the fewer the collisions affected by the object surface. This creates a thin layer of fluid near the surface in which the velocity changes from zero at the surface to the free stream value away from the surface. Engineers call this layer the boundary layer because it occurs on the boundary of the fluid.
Click to expand...

airfoil.jpg

NASA_Airfoil_in_wind_tunnel.jpg

airfoil-windtunnel-flow-composite-dots.jpg
 
It "sticks" because it flows along the curve of the wing surface. If it didn't, the air would deflect outward as soon as it hit the leading edge. Coanda effect is what does this. Coanda effect is what makes water or any other liquid "stick" to a surface, like water on a curved glass. How many times have you tried to pour water or any other liquid out of a container, only to have it run down the outside surface and spill onto the floor? That's coanda effect. Surface tension is responsible for binding liquid molecules together to form droplets, so that isn't applicable. Boundary layer is more for explaining the differences in airflow at the microscopic level close to the surface of the wing.

Anyway, that is how it was explained to me, hopefully this helps a bit.
 
Haha, thanks guys. The replies with glue were anticipated... I spent a big majority of yesterday filtering through all of the definitions I've been given over the years pertaining to lift, and stagnation point, and Magnus, and Coanda, and yadda yadda yadda.
 
You can tell the difference between someone who had a sugar momma paying for their flight training vs someone who chipped in their own dime this way: The sugar momma benefactor pays for things they can get for free. Seriously, you guys didn't know that a wing is just like a postage stamp and you get air to stick to it just by licking the back?
 
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