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Questions tagged [lift]

Lift is the aerodynamic/hydrodynamic force on a body moving through a fluid that opposes the force of gravity. DO NOT USE THIS TAG for elevators. For aerostatic/hydrostatic lift in fluidstatics use the [buoyancy] tag instead. For EM forces use the [levitation] tag instead.

Lift is the aerodynamic/hydrodynamic force on a body moving through a fluid that opposes the force of gravity. DO NOT USE THIS TAG for elevators. For aerostatic/hydrostatic lift in fluidstatics use the tag instead. For EM forces use the tag instead.

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What really allows airplanes to fly?

What aerodynamic effects actually contribute to producing the lift on an airplane? I know there's a common belief that lift comes from the Bernoulli effect, where air moving over the wings is at reduced pressure because it's forced to travel further…
David Z
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How can airplanes fly upside down?

I've read many times, including here on this very site that the commonly known explanation of flight is wrong, and that airplanes can fly because the shape of their wings deflects air down. This makes sense, but as far as I can tell it doesn't…
Javier
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What does a wing do that an engine can't?

This isn't a question of how a wing works -- vortex flow, Bernoulli's principle, all of that jazz. Instead, it's a question of why we need a wing at all. A wing produces lift, but why is that necessary? I got to this by thinking of an airplane at a…
yshavit
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Why don't rockets tip over when they launch?

Rockets separate from the launch pad and supporting structures very early in flight. It seems like they should tip over once that happens. Why don't they tip over ? Is it due to a well designed center of gravity or do they somehow achieve…
user12046
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Does a wing in a potential flow have lift?

I have a hard time understanding whether or not a wing placed in a potential flow, assuming there is no viscosity and no friction with the wing, will produce a lift. I've seen several contradictory (to me) versions of what happens in this case, in…
NikiC
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How much effect does the Bernoulli effect have on lift?

I understand that the Bernoulli effect is a flawed explanation for the cause of lift, and does not cause much at all, but how much? Is there any experimental data on the force caused by the Bernoulli effect? Maybe implicitly through data of the…
Meow
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Is flying really easier on smaller scales?

In the book Playing with Planets, the author makes the following argument, pertinent to flying robots of the future: As it is, an important law of physics says that smaller organisms fly much more easily than larger ones. This can be seen clearly…
Alan Rominger
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Can a balloon start from Earth and fly to the Moon, using Helium for lift to the top of the atmosphere and then as propellant?

The JP Aerospace's Tandem airship achieved a record-breaking 28,982 meters for the highest airship flight. After reaching this height, can the helium balloon be used as a propellant, the same way if you release a balloon without tying the end, it…
Ilya Gazman
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Would an airplane flying through superfluid helium experience lift and drag?

Would an airplane flying through superfluid helium experience lift and drag? The airplane is presumed cold enough to not heat up the helium.
yippy_yay
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Does it take significantly more fuel to fly a heavier airplane?

I was reading in the papers how some-airline-or-the-other increased their prices for extra luggage, citing increased fuel costs. Now I'm a bit skeptical. Using the (wrong) Bernoulli-effect explanation of lift, I get this: More luggage$\implies$more…
Manishearth
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Is Magnus effect a corollary of Bernoulli principle?

Magnus effect is commonly explained using Bernoulli principle. However, taking the lift on a rotating cylinder as an example, the velocity difference is caused by the extra work done by the rotating cylinder but not by the pressure difference, the…
Shadumu
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Why exactly does a boomerang return back to the thrower?

I was always intrigued by the phenomena that govern the returning back of a boomerang to the thrower. Even if it is dependent on various factors such as velocity, aerodynamics, wind resistance and so on I was wondering, there must be some concise…
Robin Maben
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Why do co-rotating vortices coalesce, but not counter-rotating ones?

In studying the aerodynamics of modern aircraft equipped with high-lift devices, I have discovered that quite a number of distinct trailing vortices are present in the immediate wake of an airplane in flight (e.g. off the outboard edge of the flap,…
Bryson S.
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Calculating the force required to lift a weight with a screw

I am trying to learn physics by myself as I do not have a good teacher at school. I've been reading Feynman Lectures on Physics and I can't figure out how he found out this number. Here is an excerpt of the book: Let us now illustrate the energy…
nonameable
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What is a Physically Accurate Explanation for the Kutta Condition?

Countless arguments between highly intelligent people have been waged (on this very site in fact) as to exactly how lift can be explained in an experimentally and mathematically rigorous way. Taking the potential flow approximation and invoking the…
Bryson S.
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