## Fluid mechanics, why does the air flow faster over the wing?

 Quote by boneh3ad So yes, indeed, the fluid parcel is moving with a constant speed of $U_{\infty}$ in an inertial frame. The problem is, this doesn't tell us a lot about the forces on the cylinder. The important quantity is the speed with respect to the cylinder.
The only point here was that the Bernoulli Principle was not at work along the surface but that the Bernoulli Equation was, based on normal acceleration.

 Quote by Stan Butchart The only point here was that the Bernoulli Principle was not at work along the surface but that the Bernoulli Equation was, based on normal acceleration.
That doesn't make any sense. Bernoulli's equation makes perfect sense in this situation, especially since we are doing this ideally. Just because the result of something is zero in a certain frame or reference doesn't mean it doesn't apply. Regardless, the important frame is that which follows the body.

 Quote by boneh3ad Bernoulli's equation makes perfect sense in this situation,
In the long run you might be right.If we only want numbers the Bernoulli Equation dos just fine. However, most of the thousands that search the web and books are only looking to uderstand the lifting process.

The largest percentage of the hundreds of articles and sites firmly define the concept that pressure changes are created by linear variations in the flow tangent and relative to the surface. (in the sense of the venturi)

There is additional group that explains that the velocity changes are in response to the pressure variations.

The primary flow is from displacement. The source/sink pattern describes the motion effects throughout the entire flowfield. These instantaneous velocity vectors are relative to the remote (still) fluid. When we add the fwd motion of the cylinder we can find the tangent velocity relative to the surface. This tangent velocity, in combination with the surface radius produces the normal acceleration, v^2/R, creating a pressure gradient that must be integrated across the entire flowfield. It is almost luck that all of this can be reduced again to the Bernoulli Equation.

We find that we can still apply the Bernoulli Equation to the tangent velocity, relative to the surface. But is this the Bernoulli Principle??

 [QUOTE=boneh3ad;3722110] Additionally, your site is quote difficult to follow. [QUOTE] boneh3ad --It appeares that I have a real problem here. If you (or anyone else) have any suggestions my "e" address is on the site. http://svbutchart.com