Quote:
Originally Posted by BeechBoy  Can anyone explain precisely HOW wingtip vortices create induced drag. I know that they do I just don't know how and have never seen any text that explains it.
p.s. Be kind to my brain in your replies - I don't have a PhD.  |
- Draw an airfoil with the leading edge to the left
- Draw the relative wind coming horizontally from the left.
- Draw a lift vector perpendicular to the relative wind.
That's life
without wing tip vortices.
Now,
- Modify the relative wind so that it comes from slightly above the first one you drew and angle it downwards.
- Draw a lift vector perpendicular to *this* relative wind.
Notice that the new lift vector is pointed slightly backwards. That's the origin of induced drag.
The modification you made to where the relative wind was coming from is due to the wingtip vortices; they tend to make the air around the wing move downward.