long wire antenna

Grab your video cameras, folks!

I never suggested doing so. I simply pointed out that lift is a differential in air pressure. It is often assumed to apply only to wing shaped objects, but this is just an assumption. I don't think anyone here seriously thinks that a straight fin in a good idea for an airplane wing.

Don't try to make an argument were there is none.

Leonard

I wasn't the idiot who suggested that waving your hand around from a car window was an example of lift.

The Bernoulli principle (the one about the faster air flow corresponding to lower pressure) is sort of like the second law of thermodynamics (the one about heat never spontaneously flowing from cold to hot). It's a shortcut way to get the right answer, but doesn't have the satisfying feel of a real physical derivation.

BTW by symmetry, symmetric wings require an angle of attack to generate lift. Otherwise how do they know which way to push?

Cheers

Phil Hobbs

Actually, it is. It might even be an example of a wing, depending on how you shape your hand. You appear to be looking for an argument and enjoy insulting people rather than fostering understanding. Oh, but that is supposed to be OK on Usenet? Sorry, intelligent discourse can take place even here.

Leonard

"AZ Nomad"

Study this page very carefully:

.... Phil

"AZ Nomad"

Study this page very carefully:

.... Phil

"AZ Nomad" <

Study this page very carefully:

.... Phil

"AZ Nomad"

Study this page very carefully:

.... Phil

Agreed, and that's the way I understood it. In fact as far as I understand it, any wing, irrespective of its sectional shape, requires an 'angle of attack' to fly, and how well a wing flies on any particular aircraft, is a function of balancing angle of attack against drag so caused, and the power input required to overcome that drag. I also understood that this was partly the reason that jet aircraft tend to land and take off with a very 'nose up' attitude, to increase the angle of attack and hence the amount of lift whilst the airspeed is relatively low.

Accepting that angle of attack, and the necessary power to drive the wing through the air being available, is the primary mechanism of lift generation, then I am having difficulty understanding why some here have contended that holding your hand out of a moving car window with an attack angle, is not a valid example of lift generation. Your arm certainly gets lighter when you do this, so is that not lift ?

Way, waaaay off topic, but a bit of a fun discussion ...

Arfa

Because it's Usenet, and half the fun is the idiotic nitpicking.

Cheers

Phil Hobbs

Too many people are ignoring him on the design newsgroup, so he's trolling here.

Wait a second. The air isn't really moving. It's the plane that is moving and the air is pretty much standing still, except where the propeller blows it around but I don't think that's the whole wing.

So the molecules that were together before the plane got there are still almost together after the wing slices through the air.

And what's the main mechanism?

forward

They were smart. They built a wind tunnel to see which wing shape had the most lift.

I think so but maybe not out of wood anymore. Actually funniest home videos last Sunday had a section on people being hit by their own planes. All were bigger than what we had, 18" wing span seemed typical (although maybe people with planes like we had can't afford video cameras, or aren't so caught up in themselves that they video little stuff like this.)

It's punched out of a flat sheet, but the slot in the fuselage is curved with the center higher. They at least believe she airfoil shape is neceessary for somethin to fly well.

I don't know what the original topic is, or tangential one for that matter.. but I do know a lot about airflow over wings.

I can tell you that if two molecules are neighbors, and they take opposite paths above and below the wing, they do -not- wind up neighbors on the trailing edge. Look at this image:

The main source of lift for an airplane is in fact the propeller. The wing diverts some of the force of the air hitting it in an upward direction (lift), and some into an impeding force (drag). The wing (and every other surface) is only designed in an airfoil shape to make it more efficient.

Whether the plane is moving through the air or the air around the plane is not important; it's a superposition thing. A small plane with a STOL (slow takeoff/landing) kit can hover, or even fly backwards, in a good stiff breeze. The pilot doesn't need to compensate for this at all (until he gets low enough for the terrain to interrupt the wind).

This is a very poorly understood concept. I've heard engineering professors botching it up before.

H> On Tue, 9 Mar 2010 01:53:39 -0000, "Arfa Daily"

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