Another "myth to kill"??.....what makes it go???

[gpflepsen]

First we should determine the mode the wing is working in should we not?:thumbsup:

I've always wondered how a wing produces lift yet a plane can fly upside down?:thumbsup:

These kind of discussions typically are endless, because they are like onions. Just when one layer is peeled away, another is presented for more madness!:laughing:

Your second question... an inverted airfoil uses a negative angle of attack to produce the different path lengths that lead to different velocities above/below the wing leading to differential pressures that form the mechanism of lift. Sounds like Bernoulli, eh? But airfoils are two dimensional and the real world is three. The resultant airflows, as Larry points out, represent vortices that are incorporated in a produced down wash. The reaction to the generation of the vortices and downwash follows Newtons laws.

Gotta run to a wedding.. Undoubtedly with more pressure in the head tomorrow morning! :laughing:

I'll leave you with a nice photo:

 

[AKKAMAAN]

Another way to say this is... velocity (flow) causes pressure. Just look at a pump curve! :laughing: Another example of the velocity/pressure interdependence is a jet pump. And look what Bernoulli figured out!

Velocity is NOT equal to flow...you can increase velocity even if flow stay constant....it is what happens in a restriction, or an air plane wing......
here is the Bernoulli tube showing the pressure loss through a restriction....

P=f(Q,R) Pressure is a function of flow and resistance,

I would rather say that flow is a function of pressure and resistance....."no force (pressure), no flow"....Q=f(P,R)...:thumbsup:
and

I had stated, for this example and the sake of simplicity, that the relationship was linear. But I think most know the relationship is really a bit more complicated than that!

I think flow is linear to resistance if pressure is constant...but hydraulic resistance is not equal to orifice diameter, neither orifice cross area, hydraulic resistance is so much more complicated than that....shape of orifice, fluid viscosity, delta P, etc etc..
If you enjoy math and calculus....spend a few hours on this one.....

Here's a semi-related question for one to ponder; would you use Newtons laws or Bernoulli's principle to explain how an airplane produces lift?

If flow stays constant and we increase velocity by making air travel a longer way on top of the wing, pressure will decrease on top of the wing and the Delta P will make the wing lift the airplane .....so it will be the Bernoulli Principle that will apply to that....

 

[AKKAMAAN]

There are engineers that dream this stuff up, and there are technicians that make it work. The end user however, is the owner, and usually brings it back to the technician to get it fixed. Even the engineer goes back to the technician to make sure it works to get the job done. I am just saying.

And the technician/end user, start changing/replacing "cylinder seals", or a pump, when they are good, because he do not know enough about the basics, to apply them in practice....:laughing::licking:

 

[AKKAMAAN]

This threads is dead now, like the myth "flow makes it go" is dead too....
I have made my point, and with out force, we cant make any thing move. Newton's law's about motion....

If you guys want to continue discussing air planes and such, please start a now thread.

I am now preparing for a new topic, that will be posted soon.....maybe about another "myth"....:thumbsup:

Later
akkamaan...."ah come on"....

 

[mmurphy]

AKKAMAAN, I have no doubt in you. After seeing your answers, replys, and just plain knowledge, if you told me there truly was a pot of gold at the end of a rain bow, I would take your word for it.:thumbsup::thumbsup:

 

[AKKAMAAN]

AKKAMAAN, I have no doubt in you. After seeing your answers, replys, and just plain knowledge, if you told me there truly was a pot of gold at the end of a rain bow, I would take your word for it.:thumbsup::thumbsup:

I sure do appreciate your "trust"! Thank you mmurphy!

Arguing for basic "knowledge", is like a case in court....we wont accept "the facts" without PROOF. Many times we build our knowledge, more on "mouth to mouth rumors" than basic logics, facts and PROOF!

Make sure to build your on your own basic "trust" foundation, so you don't have rely on others "rumors"....

One common "rumor" is that "flow makes it go", another one is that a restriction, unconditional, will control/decrease flow....but that will have to be discussed in another thread....

Over and out!

 

[J_J]

And the technician/end user, start changing/replacing "cylinder seals", or a pump, when they are good, because he do not know enough about the basics, to apply them in practice....:laughing::licking:

Perhaps you do not understand what being a technician means.. He is the guy that analyze the situation, removes the part, puts it on the test bench, and if it needs fixing, he does it. Sometimes the owner can do that also.

And then there are those people that have the knowledge, but can not fix their own tractor/hydraulic equipment because they theorize to much. Most times, one does not need the professor to exercise what knowledge one has.

Perhaps the hyd prophet has not appeared yet, but some think they are.

I try and not use smiley / faces, because you don't know how serious the person is. They may not reflect what the person is really trying to say. Sometimes they reflect distorted, or just smart as* humor.

 

[J_J]

gpflepsen,

I believe the title of that picture is called the Angel of Death. The effect you see was caused by flares, and prop wash.

 

[gpflepsen]

gpflepsen,

I believe the title of that picture is called the Angel of Death. The effect you see was caused by flares, and prop wash.

The aircraft looks like a C-5, which doesn't have props but rather turbofan engines. The smoke from the flares offer a means to see the airflow pattern which is the result of the creation of lift. Think Newton's F=ma, the force keeping the aircraft in the air is a result of the acceleration of the air. The vortex is generated from the air trying to move from the high to the low pressure area of the wing. Clouds in the first picture and flares in the helicopter pic show this too.

Akkamaan, sorry if you think I was trying to discount your myth debunk, I wasn't. I look forward to your next installment

 

[J_J]

Related to velocity. force and direction.

YouTube - Lockheed C-130 / AC-130 Dropping Angel Wing Flare Pattern

http://www.youtube.com/watch?v=TcJTISrVEFo&NR=1