"Simple Simon" wrote in message ...
Just out of curiosity, Jan-Olov, what boat do you sail?


"Jan-Olov Newborg" wrote in message om...

Very good webpage about physical Sail/Lift Theory Pim!

The best I have seen so far on the web!

Mikko in Finland has a very good page also with airflow computer
animations.

It´s only Navier-Stokes Lift calculations that comes close to the real
physics!

Prandtl "Lifting Line Theory" is only useful for a physical non
existing "ideal/perfect fluid" created only by mathematical equations!


Jan-Olov Newborg

Today I sail an old English boat called Vivacity, a very slow type!

I have been on board Americas Cup/Volvo Ocean Race Cup boat, "Assa
Abloy and the catamaran "Nokia" sailing with 265 m2 sailarea.

By the way, do you belive in "Bernoulli law" , saying that "High
Airflow velocity causing Low Pressure"?

That should mean the the jetblast behind an F-16 Fighter running on
afterburner should create low pressure!

But thats not being the case! The total pressure is very high due to
the high dynamic pressure!

The Venturi effect you discuss is pure due to "The Coanda effect" and
the turning of the airflow along the walls of the divergentpart of the
pipe!

How local pressure gradients are created by turning the fluidflow you
can read he

http://www.scienceweb.org/movies/aero.htm

Jan-Olov Newborg

Here are some links of flow physics (not flow mathematics):

A Physical Description of Flight ©
http://www.aa.washington.edu/faculty/eberhardt/lift.htm

Bernoulli Versus Newton
http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html

What is Ground Effect?
http://home.mira.net/~radacorp/ground_effect.html

Operational use of angle of attack (AOA) on modern commercial jet
airplanes
http://www.boeing.com/commercial/aer...12/attack.html

Weltner Lift
http://www.rz.uni-frankfurt.de/~weltner/
http://www.rz.uni-frankfurt.de/~welt...ht/PHYSIC4.htm

Weltner Bernoulli
http://www.informatik.uni-frankfurt..../MIS/mis6.html

Incorrect theory number three
http://www.grc.nasa.gov/Other_Groups...ne/wrong3.html

Lift from flow turning
http://www.lerc.nasa.gov/www/K-12/airplane/right2.html

Jef Raskin - Coanda Effect: Understanding Why Wings Work
http://www.jefraskin.com/forjef/jefw...da_effect.html

F18 Soundbarrier and highspeed pass
http://www.algonet.se/~newborg/

Beaty Gif pictures smokepuls plus SAAB 2000
http://www.amasci.com/wing/airgif2.html

Prof. Colombinis photogallery
http://www.diam.unige.it/~irro/gallery.html

Flow around an airfoil
http://www.diam.unige.it/~irro/profilo_e.html

ScienceWeb - Aerodynamics
http://www.scienceweb.org/movies/aero.htm



Lift from spinning balls

This website gives a lot of references all back to Newton/Robbins!

The Magnus Effect
http://www.geocities.com/k_achutarao...ew_magnus.html

The Science of Swing, maintained by James Foster
http://www.soest.hawaii.edu/GG/STUDE...ter/swing.html

Normal Swing
http://www.soest.hawaii.edu/GG/STUDE...er/normal.html

Reversed Magnus effect explained
http://www.soest.hawaii.edu/GG/STUDE...r/reverse.html



Wrong lift explanations

Smithsonian
http://www.nasm.edu/galleries/gal109/NEWHTF/HTF510.HTM



False Bernoulli explanations

How things fly, an interactive gallery. Bernoulli Brain-Teasers.
Activities you can do at home
http://www.nasm.edu/galleries/gal109...XT/TEASERS.HTM

US AirForce Museum
http://www.wpafb.af.mil/museum/zone/ff3.htm

Dr. John S. Denker online aerodynamic book. Wrong Lift explanation
explained by "Circulation flow 'creating' the Velocity Field"
http://www.monmouth.com/~jsd/fly/how/htm/
http://www.monmouth.com/~jsd/fly/how/htm/airfoils.html