europa-list
[Top] [All Lists]

RE: SV: Europa-List: Re: wing lift/drag pins

Subject: RE: SV: Europa-List: Re: wing lift/drag pins
From: William Daniell <wdaniell.longport@gmail.com>
Date: Wed, 3 Jul 2013 07:45:41
This whole discussion has been fascinating.  IMHO lot of the discussion 
is
related to the difficulty of describing a three dimensional event in 
words
(by the way I admire Frans=92 and Svein=92s grasp of English)


As I understand this and for the purposes of the discussion 


Motive power is provided primarily from the fuselage in the form of

1.       the engine when running

2.       or in its absence the mass of the aircraft which is mostly
concentrated in the fuselage being acted upon by the acceleration 
provided
by gravity.


Drag affects the aircraft all over its surface but in level flight the 
wings
are forced toward the rear of the aircraft by the relative wind acting 
upon
the leading edge.


The wings provide the majority of the lift (a minimal being provided by 
the
fuselage) in two ways but can only be created by forward motion with 
respect
to the relative wind.  (if the relative wind is zero then it wont fly)

1.       benouille=B4s effect which is perpendicular to the cord

2.       force of the relative wind against the lower surface of the 
wing.
I am assuming that this varies in a complex way.


One can see the in level flight the mass of the aircraft is supported by 
the
wings and this support is transmitted by the 4 points at which the wings
connect to the fuselage.  The force of the relative wind against the 
leading
edge trying to fold the wings to the rear of the aircraft is being
counteracted by the rear lift sockets and (I would also guess) by the 
main
wing spars.  So in this case the tie bar is in compression.


I have difficulty with visualizing how the tie bar could be in tension.  
I
suppose that with the relative hitting the lower surface of the wing at 
a
high angle of attack on could foresee a force component towards the 
front of
the fuselage though not in the direction of flight but it seems hard.  
Maybe
Rons engineer can try to explain it to us less technical folks.


I am continually surprised by what I learn on the forum.


Yours


Will

Bogota


From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of GRAHAM
SINGLETON
Sent: Tuesday, July 02, 2013 09:01
Subject: Re: SV: Europa-List: Re: wing lift/drag pins


Glad I didn't upset everyone {{!-)
Graham


  _____  

From: Pete <peterz@zutrasoft.com>
Sent: Tuesday, 2 July 2013, 14:54
Subject: Re: SV: Europa-List: Re: wing lift/drag pins


Thx Graham,


My sentiments exactly.


And to the question of why the spars are strapped together, and why one 
pin
has to be a pip pin, is because we have simple overlapping spars, and 
not
fork spars, so the asymmetrical load on the pins wants to twist them 
off, as
the spar ends gets forced away from the other spar.


Cheers,

Pete


On Jul 2, 2013, at 8:19 AM, GRAHAM SINGLETON
<grahamsingleton@btinternet.com> wrote:

Svein
I admire your patience and courtesy,  



<Prev in Thread] Current Thread [Next in Thread>