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The_navigatorŠ
 
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Default how a sail works, who can help me explain?



Jan-Olov Newborg wrote:
The_navigatorŠ wrote in message ...

Jan-Olov Newborg wrote:

The_navigatorŠ wrote in message ...


Where do you get these ideas? Of course energy conservation laws
consider (and implicitly include) friction losses, compression and
turbulence.

Now just because you are familiar with *one* form of the Bernouille
equation does not mean that is the only form. It is possible to derive
forms for any set of integral boundary conditions with the proviso that
you follow a streamline for continuity. Finally, although you seem to
have missed it, the Bernoulli equation expressly considers compression
of a fluid. -it comes into the density term(s).

As I said, we understand how a sail works but you seem to be struggling.

Cheers MC


Leonard Eulers so called "Bernoulli equation" is the 1D (one
dimensional case) of his 3D equations for an non existing,
mathematical modeled fluid!


Hahahahhah. Does energy exist?


Bernoulli equation is the integralform of Newton second law F=m*a!


Bzzzzzzzzt wrong.


It is easier to show the direction of the Lifting Force using Newton´s
second law directly.

Many books explain Lift with the so called "Bernoulli effect", which
means that " high airflow velocity causes low airpressure"!


Bernoulli does not say that. It is the misinterpretaion of the equation
by mathematically impaired people that says that.


Professor Dooley shows here below that this is wrong:

According to Professor Dooley, Millerville University, it will take
one generation to understand Bernoulli equation and that " high
velocity does not causes low pressure".


Yawn. So he's the only genius that can understand the derivation of an
equation? Is this not a wonderful exaple of a one eyed man in a velley
of the blind?


http://muweb.millersv.edu/~jdooley/m...erap/eulap.htm

Professor Dooyley writes down the page:

"One confusing detail about Bernoulli's equation needs discussion: In
elementary treatments it is often stated that, because of Bernoulli's
equation, high velocity causes low pressure.


Note the ELEMENYTARY! In this NG we are not at ELEMENTARY level and are
so far above average understanding of how a sail works and how to make
it work at close to 100% efficiency that people like Dooyley have
nothing of value to offer.


In real aerodynamic books one never finds the expression "Bernoulli
Effect"!


Yawn. Of course.


Wings of all new airliners are almost flat on upper surface!




That´s called "Supercritical Wings" and they save their operators (as
example airbus340 ) some 15 % over older aircrafts (Boeing 747-400)!


Now you are being really silly, do you think sailboats work in the
spercritical regime?


http://aerodyn.org/HighSpeed/supercritical.html

They now have longer airflow path below the wing compared to to upper
surface!

Some Professors explains Lift with "The Circulation Theory"! But
Potential Theory and it´s correction, the superpositioned "Circulation
Field" is not reality, only a mathematical model!


Say my model of you is a mathematical midget. Does that mean it's
incorrect -just because it is a model?

Cheers MC



You don´t seems to understand the fluid flow physics and it´s
connections to mathematical idealized models!


Silly boy, all phsyics is model based!


PIM s webpage shows the real physics!


Yawn


Once Professor Hoerner wrote: "Only a mathematician can create Lift by
means of a Line"! (Lifting Line Theory).


Hyperbole.


If you are a mathematical midget or not I don´t know!



At last a correct statement! Yes you don't know -in fact you have no idea!

Cheers MC