Why Does Drag Produce Lift? | Dynamics

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Discussion Overview

The discussion revolves around the relationship between drag and lift in the context of aerodynamics, specifically questioning whether drag can produce lift or if lift inherently produces drag. Participants explore various aspects of lift generation, including pressure differentials and the role of airfoils.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants argue that lift produces drag, while others suggest that drag can produce lift, indicating a dependence on perspective.
  • One participant explains that lift is generated by a pressure differential, with lower pressure above the wing compared to below it.
  • Another participant challenges the notion that lift is solely due to pressure differentials, suggesting that other factors, such as the design of fully symmetrical airfoils, play a significant role in lift generation.
  • There is mention of confusion in a referenced thread, with some ideas being correct and others not clearly defined.

Areas of Agreement / Disagreement

Participants do not reach a consensus, as there are multiple competing views regarding the relationship between drag and lift, and the mechanisms behind lift generation remain unresolved.

Contextual Notes

Some claims about lift generation depend on specific definitions and assumptions about fluid dynamics and airfoil design, which are not fully explored in the discussion.

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why does drag produce lift?
 
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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).
 
thanks! :)
 
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.
 
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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