The Physics of Wing Lift...Logic versus tradition.

[Trevor]

eccentrically,....you are talking about what a plane does or what it is designed to do,for instance,when the plane drops,the tail drags the back of the plane up to put it into a steep dive to restore lift.
Please understand, I am dealing with the basic principle of wing lift only.
That is what the plane is about,otherwise it would not exist as a craft.

[Trevor]

To return to the subject of high speed air.
No real logical explanation is given for the drop in pressure of the air through a venturi.
Here's what happens.
First of all lets all agree,there is no such thing as suction.It's only pressure through Brownian motion of the air to expand into space.
If you force air under pressure through a constriction it actually expands even faster from a high to a lower pressure.This catapulting of the air reduces the pressure of the air behind.
As in the flow over the wing, it's the vacuum on flowing air near the surface that causes it to accelerate faster that the denser layer.

[eccentrically1]

not just planes. birds, but they aren't talking.
we can't talk about wing lift and ignore drag, they work in unison. if we didn't have drag, we wouldn't have lift. the difference in speed and pressure that produces lift relies equally on drag to produce the difference in the first place. the basic principle is the differential exploited in the wing-air system.

[Trevor]

Yes of course we all agree on that and the greater the angle of attack the more drag without question,but the angular momentum imposed on the air that creates the low pressure is not the whole story.

[daanopperman]

Hi Trevor ,

To state that " when the plane drops , the tail drags the back of the plane up to put it into a steep dive to restore lift " is not what happens . Planes are designed to go into a save orientation when thrust is lost , whether it is form a gas engine/jet engine or a glider . In a glider the thrust comes from the glide ratio .
You have 2 " point's " where 4 things come into play . The 4 things is 1 - center of Thrust , 2 - center of Drag , 3 - center of Lift , and 4 - is COG of the plane .
The COG is located forward of the center of lift . The center of Thrust is placed below the center of Drag .
The Thrust plus the Drag keeps the plane in a " nose up " orientation . If Thrust is lost , you loose some lift and Drag is reduced , this will cause the GOG to pull the nose down as it is forward of center of Lift which was also lost , by going into a nose down orientation , Thrust is " restored " through increased airspeed , lift is regained , and drag is restored to ensure control is possible .

[eccentrically1]

Why would there be a vacuum?
A vacuum is zero pressure, technically it doesn't exist ,even space has some particles.
Let's just all agree it's low pressure above the wing, but not a vacuum.
Pressure is in the formula. If the pressure above a wing reached zero, what does the formula predict would happen?

[Trevor]

Hi Daanopperman, I'm sorry I did not want to rob from the charm of the beautiful airplane design in considering what makes the plane so stable at velocity. To analyzing something I look at the object not as a plane but as a craft that has parts joined on to stabilize it.
Just for a moment imagine the plane without a tail and without an engine. When it reaches stall speed it would just drop straight down like a stone with out correcting itself even though it still has a wing.
I am aware of all the ingredients that make a plane stabilize itself and it is a masterpiece of design which is still evolving into new configurations to make it better.
This whole debate is about the mechanics of wing lift.

[Trevor]

I don't expect my explanation to be accepted willingly straight away, it usually takes a while of meditation to really dawns on the intellect.
Here is a simple example of what I mean.
If you put a golf ball and a table tennis ball in a wind tunnel, which ball will fly away the fastest under pressure on the wind?...the lightest ball of course.
The same goes for the thinnest lightest air in the vacuum closest to the wing surface.
The high speed air does not cause the vacuum, instead the vacuum causes the high speed air.

[johannesbender]

i am not sure what this thread is really about but to assume an aircraft
non rotary wing without the stabilizers will simply drop down during
a stall is wrong first you have to state the airfoil design because there are
flying wings wich needs no tail stabilizers to keep the angle of attact
in correct orientation , secondly a wing of design that requieres a stabilizer
will without that stabilizer fall like a leave pitching up and over again and again
ofcourse cog to chord is important for stability and responsiveness too , but there are other
factors that attribute to sell correcting flight like having a high wing and making use
of liberal dihedral angle and the correct angle of attack of the fixed wing and many other things
but alot of earodynamics apply in a manner to fluids too , a bit diffrent but if you
are talking of a theory about drag lift and things you would neef to apply
it to fluids too

[AB Hammer]

Vacuum is space that is devoid of matter. The word stems from the Latin adjective vacuus for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure.[1] Physicists often discuss ideal test results that would occur in a perfect vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. The Latin term in vacuo is used to describe an object as being in what would otherwise be a vacuum.

Trevor

You seem to be confusing Vacuum with Vacuum cleaner. A vacuum cleaner is somewhat misnamed but understood to suck. What is some call a vacuum but in truth is air flow (the air has to go somewhere). What you are saying is true in air flow or the effects of the equalization of an atmosphere to a vacuum equaling out and of course no longer a vacuum. Apollo 11 astronauts did the test on the moon of the feather and I believe a rock, dropped at the same time and they both hit the ground at the same time. Thus the effect of in a vacuum and low gravity.

[Trevor]

You guys have totally missed the point and strayed off the subject.
I was talking about a relative vacuun compared to the normal air pressure.
In other words the gradiant drop in air pressure that the angle of attack of the wing gives to air through angular momentum.

[AB Hammer]

Trevor

With out a point of reference? Things said tend to be open to interpretation. You have never posted a picture or diagram which leaves more questions than proper direction.

Why have you never posted a picture or diagram? This would make it a lot easier to follow what you are trying to say.

Alan

[Trevor]

Yes Allan, sorry I realize now that it is the problem of conceptions.
When I write my book every argument will be accompanied by a diagram.
I would like to learn how to do diagrams and pictures on this forum because I am going to need it when I have to demonstrate my working wheel soon.

[jim_mich]

I would like to learn how to do diagrams and pictures on this forum ...

Click here for instructions on how to upload pictures.

[AB Hammer]

Yes Allan, sorry I realize now that it is the problem of conceptions.
When I write my book every argument will be accompanied by a diagram.
I would like to learn how to do diagrams and pictures on this forum because I am going to need it when I have to demonstrate my working wheel soon.

No Trevor, it is a problem of lack of description of how they relate without the point of reference.

I myself avoid the word conception due to it's fist meaning. LOL
To conceive of an idea is the first part for the first person to express who came up with the thought. Here is another way I have a bit of trouble understanding what you are saying.
When you say vacuum. I want to know how you are creating that vacuum.
When you say wind speed. I want to know how you are creating that wind speed.
This is because these machines must drive themselves or they are just wishful thinking.

Alan