Benouilli Effect: How Airplanes and Paper Fly

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    Airplanes Paper
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Discussion Overview

The discussion centers around the Bernoulli effect as it relates to aerodynamics, particularly in the context of airplane wings and other applications like blowing over a piece of paper. Participants explore the underlying principles, misconceptions, and implications of the effect in both theoretical and practical scenarios.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant describes the Bernoulli effect as the principle behind lift in airplane wings, suggesting that faster air over the top of the wing results in lower pressure.
  • Another participant challenges the idea that the air travels faster over the wing due to a longer distance, arguing that it is a common misconception and that the air actually gains gravitational potential energy.
  • There is a discussion about the relationship between kinetic energy and gravitational potential energy, with one participant questioning how a drop in gravitational potential energy leads to lower pressure over the wing.
  • Concerns are raised about the application of the Bernoulli effect to other scenarios, such as blowing over a piece of paper, with questions about where the gravitational potential energy loss occurs in that context.
  • One participant expresses uncertainty about their understanding and acknowledges the need to revisit the material, indicating they will study further resources, including a NASA website.
  • Technical details are provided regarding Bernoulli's equation, mass continuity, and isentropic flow relations, with a participant explaining how these concepts interrelate in the context of airflow over wings.
  • There is mention of the Venturi effect and its implications for airflow in natural environments, suggesting further exploration of this topic.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of the Bernoulli effect, with some agreeing on its basic principles while others contest specific aspects, particularly regarding gravitational potential energy and its role in airflow dynamics. The discussion remains unresolved with multiple competing views present.

Contextual Notes

Participants note that the Bernoulli effect has been removed from some academic syllabi, which may limit understanding for students entering related fields. There is also mention of the complexity of isentropic flow relations and their applicability, indicating that some mathematical concepts may be challenging for participants.

Who May Find This Useful

This discussion may be of interest to students and enthusiasts of aerodynamics, fluid dynamics, and physics, particularly those looking to understand the nuances of the Bernoulli effect and its applications.

  • #31
Thanks for the suggestions, Fairfield. The dashes were not moving, and nothing I did would make them start. WebTv can download nothing. It's just a modem and a keyboard. Not even a mouse - you have to use the arrows. (I can plug a printer in, which I have done, because these just print straight off the web.)

-Zooby
 
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  • #32
Try a little common sense, Fairfield: A symmetric airfoil's upper and lower surfaces are the same, yet the plane flies ... Ever hear of a little something called 'angle of attack'?
 
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  • #33
Originally posted by Chagur
Try a little common sense, Fairfield: A symmetric airfoil's upper and lower surfaces are the same, yet the plane flies ... Ever hear of a little something called 'angle of attack'?

Did I say something to the contrary somewhere? Please quote me.
 
  • #34
Originally posted by Chagur
Try a little common sense, Fairfield: A symmetric airfoil's upper and lower surfaces are the same, yet the plane flies ... Ever hear of a little something called 'angle of attack'?
Fairfield did not describe what he saw, so what fuels this testy attitude and irritation? You can read minds?
 
  • #35
This was your quibble:

Originally posted by zoobyshoe
OK, this part here is confusing to me because I don't see how they can possibly measure the velocity of any individual particle, much less all of them.
I was simply trying to explain how you could attain a value for the r.m.s. speed, since as you said, it is not possible to measure the velocity of each individual particle.
 
  • #36
Yes, Fairfield, you did:
The importance of the "lift" airfoil design is over hyped
because most airplanes can be flown upside down
without losing altitude, it just takes more gas.
Completely ignoring that when flying 'upside down' you
are relying completely on an increased angle of attack
and that the required AofA increases drag; hence the
greater power/fuel requirement.

No, zoobyshoe, I cannot read minds, but I do know a little
about aerodynamics. A simple vector force analysis is all is
all that is required to determine even extremely slow flight
or 'flight' via turbulence creation, the 'flapping of wings',
either by birds or insects.

Given the required control surfaces and sufficient power,
even a kitchen table can be made to 'fly'. An excellent
example would be 'the hopeless diamond' which became
the F-117 in its combat configuration.
 
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  • #37
OK Chagur, I over simplified the problem. I completely agree with you.
 
  • #38
Originally posted by Chagur

No, zoobyshoe, I cannot read minds...
That's good, cause neither can anyone else here. Therefore quote the remark you are taking exception to, especially when you are being irritated and testy about it, because otherwise it looks like you are referring to the last thing said.
 
  • #39
Originally posted by Chagur A simple vector force analysis is all is
all that is required to determine even extremely slow flight
or 'flight' via turbulence creation, the 'flapping of wings',
either by birds or insects.

Given the required control surfaces and sufficient power,
even a kitchen table can be made to 'fly'. An excellent
example would be 'the hopeless diamond' which became
the F-117 in its combat configuration.
I am not sure why you are directing this explanation at me. I am the one who said earlier that it is possible to design a wing that works exclusively on Newton III.
 
  • #40
Originally posted by zoobyshoe
Thanks for the suggestions, Fairfield. The dashes were not moving, and nothing I did would make them start. WebTv can download nothing. It's just a modem and a keyboard. Not even a mouse - you have to use the arrows. (I can plug a printer in, which I have done, because these just print straight off the web.)

-Zooby

Now that webtv has been exposed, may I suggest an economical computer with a Windows operating system, and all the needed extras, which can be had for about $440 (before tax and shipping) at

" http://www.tigerdirect.com/applications/Category/category_tlc.asp?CatId=6 "

If you love the frustration of installing the operating system yourself you can get a computer for about $300, and buy a slightly passe version of Windows at

http://www.recycledsoftware.com/

for about $100. The software sold there is not used, just superseded. Make sure you get an OEM version of Windows, and not earlier than Windows 95, if you buy it. You'll still need to get a monitor, or else an adapter card to use your TV as a monitor.
 
  • #41
Not a bad suggestion at all, except my finances are such that the odd 4 or 5 hundred dollars that comes my way must always go to maintaining my vehicle, among other more pressing things.

The webtv is as limited as you can get and still be on the web, and I find I have to make excuses for it frequently, but it is cheap and, at this point, that overides the limitations.
 

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