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-   -   how a sail works, who can help me explain? (https://www.boatbanter.com/asa/16239-how-sail-works-who-can-help-me-explain.html)

Simple Simon July 10th 03 10:51 PM

how a sail works, who can help me explain?
 
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




The_navigator_© July 10th 03 11:45 PM

how a sail works, who can help me explain?
 
Didn't you break them stuffing them in the bag?

Cheers MC

Capt. Mooron wrote:

Kinda makes sense in a way.... I had full battens installed a few years ago
on my bagged main and noticed a big difference in point and speed.

The full battens induce a nice curve even in the lightest air.

CM


"PIM" wrote in message ...
| I am suggesting a curved plate works better!






The_navigator_© July 10th 03 11:55 PM

how a sail works, Windtunnel Tests.
 
Hahahhahahaha. Can't even put the correct letters after you name? Talk
about a vacuum!

Cheers MC

dowra wrote:

The_navigator_© wrote in message ...


Guess thats why you get sucked aground eh?

Cheers MC



Very witty and informative response! Duh, wish I waz da navagatar tu.
Farr boats are garbage.
Cheers M(ore)C(ock)last name P(lease)
DOWRA the Physicist. BS. MS. member NASPS.





Capt. Mooron July 11th 03 04:28 PM

how a sail works, who can help me explain?
 
OOPS.......

CM


"The_navigator_©" wrote in message
...
| Don't be silly. Read the thread!
|
| Cheers MC
|
| Capt. Mooron wrote:
|
| You bag your main??????
|
| CM
|
| "The_navigator_©" wrote in message
| ...
| | Didn't you break them stuffing them in the bag?
| |
| | Cheers MC
| |
| | Capt. Mooron wrote:
| |
| | Kinda makes sense in a way.... I had full battens installed a few
years
| ago
| | on my bagged main and noticed a big difference in point and speed.
| |
| | The full battens induce a nice curve even in the lightest air.
| |
| | CM
| |
| |
| | "PIM" wrote in message
...
| | | I am suggesting a curved plate works better!
| |
| |
| |
| |
| |
|
|
|
|
|



Jan-Olov Newborg July 12th 03 07:47 AM

how a sail works, who can help me explain?
 
"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

spock July 13th 03 11:18 PM

how a sail works, who can help me explain?
 
By the way, do you belive in "Bernoulli law" , saying that "High
Airflow velocity causing Low Pressure"?


I believe in the phenomena of decreased internal pressure with
increased stream velocity.


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


If that were true it should mean that you could put jet fuel in a
container and ignite it and then low pressure will suck the container
into a ball.


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


And that would be due to the expansion of gases among other things
associated with the combustion of jet fuel.

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


Local pressure gradients are created by a solid object and a relative
airflow pushing and pulling on each other. This pushing and pulling is
what turns the relative airflow. Local pressure gradients are a
characteristic of this pushing and pulling not the cause. You got the
horse before the cart. Its like saying cars go fast because of miles
per hour.

The_navigator_© July 14th 03 12:38 AM

how a sail works, who can help me explain?
 
Why don't you read them yourself? WE already know how a sailboat works.

Cheers MC

Jan-Olov Newborg wrote:

"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





Thomas Stewart July 14th 03 05:25 PM

how a sail works, who can help me explain?
 
Spock,

I suggest you consider the names of the fuel and the engnes , Jet fuel,
Jet after brners, jet fighters and try to imagine the operations that
created those names

OT


Jan-Olov Newborg July 15th 03 07:52 AM

how a sail works, who can help me explain?
 
The_navigator_© wrote in message ...
Why don't you read them yourself? WE already know how a sailboat works.

Cheers MC


Since you try to explain the sailforces using false "longer airflow
path behind the sail and sail beeing a "half venturi pipe", you seems
to need more correct physical flow information!

Jan-Olov Newborg


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

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


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




--


Jan-Olov Newborg July 16th 03 07:26 AM

how a sail works, who can help me explain?
 
The_navigator© wrote in message ...
Don't be silly I never said such a thing. BUT energy conservation laws
do apply.

Cheers MC


BUT energy conservation laws does not consider friction losses,
compression and turbulence.

They are a result of a mathematical construction for an non existing
mathematical perfect fluid.

Prof. em John D. Anderson,Maryland University, writes in one of his
aerodynamic books, that Bernoulli equation can be used only for a
straight centerline of a venturi pipe, and then you have not
considered the compressibility of the fluid along that centerline!


Jan-Olov Newborg


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