Dyanmics question

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why does drag produce lift?
 

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  • #2
FredGarvin
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FredGarvin said:
It's the other way around. Lift produces drag. Wellllll....I guess it depends on how you look at it I guess.

I recommend sittting back for an hour or so and read this thread:
https://www.physicsforums.com/showthread.php?t=68355

Actually, that thread is filled with a lot of consfusing ideas, some of which
are actually correct.

Lift is the force on a wing (hopefully upward) which is created by the
fact that the pressure above the wing is lower than the pressure below it.

Drag is a force that wants to push the wing in the direction that the air
is flowing.

The engine must supply power to overcome the drag or the plane will
slow down. Drag is the reason why your paper airplanes eventually fall
onto the ground.

The tricky part is that lift could not happen in a fluid or gas that did not
also have drag. This is why people originally thought airplanes were
impossible because they were studying the equations of fluids which
did not have drag-type effects (zero viscosity, see Helmholtz).
 
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thanks! :)
 
  • #5
FredGarvin
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Antiphon said:
Actually, that thread is filled with a lot of consfusing ideas, some of which are actually correct.
Care to fill us in as to which ones are incorrect?

Antiphon said:
Lift is the force on a wing (hopefully upward) which is created by the fact that the pressure above the wing is lower than the pressure below it.
If you believe that lift is solely generated by the pressure differential then you didn't read that thread. There are other, more predominant aspects that produce lift, i.e. fully symmetrical airfoils.
 
  • #6
Clausius2
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FredGarvin said:
Care to fill us in as to which ones are incorrect?

If you believe that lift is solely generated by the pressure differential then you didn't read that thread. There are other, more predominant aspects that produce lift, i.e. fully symmetrical airfoils.
This is always the never ending discussion. :biggrin:
 
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