New Products Flash Sale
Thread Tools
Old Feb 11, 2012, 03:25 PM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
The Pressure Data Logger is very good. I can now measure the different low pressure on the lee side. This test wing is a rigid plywood sheet with 3 different measuring points. You can se that the biggest pressure drop is between the half and the end of the test wing. That explains the Jet stream formation. More details will come later.
Sign up now
to remove ads between posts
Old Feb 12, 2012, 01:11 PM
Plantoflap is offline
Find More Posts by Plantoflap
Registered User
Kjell,
As a sailor, have you noticed that sailboats move into the wind without fanning or flapping or jet stream? Why?
George
Old Feb 13, 2012, 11:25 AM
krap101 is offline
Find More Posts by krap101
Registered User
I thought I might add, that flapping produces lift because of the phase difference between the pitch angle and the dihedral angle of the wing, and if the phase is correct, you can change the direction of the lift. If the wing were totally rigid and the pitch angle did not change, it would produce zero lift since the alternating vortices would effectively cancelout any lift. In ornithopters, this is accomplished by using a flexible wing, which passively causes the pitch and dihedral to be out of phase. The reason you see a larger drop in pressure near the edge of the plate is because it is moving faster (look up the bernoulli effect), and the reason you see a equalization of pressure at the end is the same reason why winglets are being incorporated into newer plane designs, to reduce the drag induced by wingtip vortices, because the high pressure air on the bottom is recombining with the low pressure air on top of the wing.

As to lift vs thrust... they're quite similar... but in this case, I'll have to agree with George. A propeller produces "thrust" because it is a rotating wing, i.e. producing lift.

Try a test using dry ice+water (creates fog) or smoke, and look at a rigid wing flapping while level. Alternatively there's dozens of papers on the topic.
Old Feb 13, 2012, 11:47 AM
Larry Jolly is offline
Find More Posts by Larry Jolly
Registered User
Larry Jolly's Avatar
KRap101 how is Patrick's tail coming........
Old Feb 14, 2012, 03:15 AM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
Quote:
Originally Posted by krap101 View Post
I
Try a test using dry ice+water (creates fog) or smoke, and look at a rigid wing flapping while level. Alternatively there's dozens of papers on the topic.
Dry ice test.
Downwash on fanning wing (0 min 3 sec)
Old Feb 14, 2012, 04:12 PM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
The Pressure Data Logger is very good. I can now measure the different low pressure on the lee side. This test wing is a rigid plywood sheet with 3 different measuring points. You can se that the biggest pressure drop is between the half and the end of the test wing. That explains the Jet stream formation.

KJELL EFFECT (1 min 54 sec)
Old Feb 15, 2012, 04:50 AM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
This is a good demostration what hapen when the AOA is fast altered and coming over the stall limite. Fast piching is not the same as fanning. The Fan-Effect starts when the TE tipspeed is faster than the relative wind speed.
Old Feb 15, 2012, 02:47 PM
Plantoflap is offline
Find More Posts by Plantoflap
Registered User
Quote:
Originally Posted by KJELL View Post
This is a good demostration what hapen when the AOA is fast altered and coming over the stall limite. Fast piching is not the same as fanning. The Fan-Effect starts when the TE tipspeed is faster than the relative wind speed.
K: >>This is a good demostration what hapen when the AOA is fast altered and comming over the stall limite.<<
Your videos and drawings always show pitching above the stall limit. Pitching below the 'stall limit' is called the 'Katzmayr effect'.

K: >>The Fan-Effect starts when the TE tipspeed is faster than the relative wind speed<<
Robert Musters' birds fly in the fastest relative wind I've seen, yet are not flapping
amazingly fast. By your own logic his birds don't use your theory.

K: >> Fast pitching is not the same as fanning.<<
Only because you call it fanning.

Stay in school kids.

George
Old Feb 15, 2012, 03:05 PM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
I like very much your way to donít understand the differences between fanning and pitching.
Pitching produce stall. Fanning produce stall delay.
Old Feb 15, 2012, 04:15 PM
Plantoflap is offline
Find More Posts by Plantoflap
Registered User
Quote:
Originally Posted by KJELL View Post
I like very much your way to donít understand the differences between fanning and pitching.
Pitching produce stall. Fanning produce stall delay.
Is that your responce to my comments in post# 24?, that I don't understand what you said? Thats sad Kjell.

You claim fan-effect only works when TE velocity exceeds the relative wind, but Robert Musters' birds disprove that.
Where is your responce to that?
George.
Old Feb 15, 2012, 05:59 PM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
Quote:
Originally Posted by Plantoflap View Post
Is that your responce to my comments in post# 24?, that I don't understand what you said? Thats sad Kjell.

You claim fan-effect only works when TE velocity exceeds the relative wind, but Robert Musters' birds disprove that.
Where is your responce to that?
George.
Why don’t ask Robert how hie produce the necessary thrust to fly so well.
Old Feb 15, 2012, 08:10 PM
Plantoflap is offline
Find More Posts by Plantoflap
Registered User
Quote:
Originally Posted by KJELL View Post
Why donít ask Robert how hie produce the necessary thrust to fly so well.
Robert's good results speak for him and good,honest engineering.

Your self contradictions speak for you and your theory.

Your job is to prove all your claims, but you can't

George
Old Feb 16, 2012, 02:53 AM
KJELL is offline
Find More Posts by KJELL
Kjell Dahlberg
KJELL's Avatar
Quote:
Originally Posted by Plantoflap View Post
Your self contradictions speak for you and your theory.

Your job is to prove all your claims, but you can't

George
George.
Fist of all. I donít have to prove anything. I am not trying to sale anything to anybody. I am only sharing my result from my private investigation about Fan-Flapping propulsion. You are a very negative person and I like to know your background for this actitud.
Nobody is blinder than the person that donít like to se.
Kjell
Old Feb 16, 2012, 02:49 PM
Plantoflap is offline
Find More Posts by Plantoflap
Registered User
Quote:
Originally Posted by KJELL View Post
George.
Fist of all. I donít have to prove anything. I am not trying to sale anything to anybody. I am only sharing my result from my private investigation about Fan-Flapping propulsion. You are a very negative person and I like to know your background for this actitud.
Nobody is blinder than the person that donít like to se.
Kjell
You are not just sharing ideas about flapping flight and mechanics, all those ideas are welcome here. It is the propaganda part of your presentation that I don't like.
George


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Poll The Palin effect in 2008 Eljimb0 Life, The Universe, and Politics 26 Sep 12, 2011 11:15 AM
Discussion Membrane wings upgrades by Mr KJELL khaled_abobakr Ornithopters 1 May 07, 2010 02:52 PM
Discussion We all know about ground effect, but how about ceiling effect? 41North Coaxial Helicopters 3 Jul 02, 2008 06:58 AM
Does the Doppler effect effect your plane? Mat Electric Plane Talk 11 Nov 13, 2004 11:29 PM