Spitfire XIV vs Bf-109 K-4 vs La-7 vs Yak-3

Soren · 05-20-2008, 02:02 PM

Is it because I have to simplify it for you Bill, is that it ???! Ok sure;

The Fw-190's wing was twisted 2 degree's but left straight at the ends so that under G's the twist was removed, thus creating elliptical lift distribution over the wing. And as we both seem to know ellipitical lift distribution is sought after because it offers the best 'e' value (Which is used to acquire the Cdi).

drgondog · 05-20-2008, 02:37 PM

Quote:

Originally Posted by Soren

LoL ! Wiggle wiggle! Trying to dodge the subject at hand are we Bill ??

Crumpp & Lednicer agree that the the Fw-190 achieved elliptical lift distribution in turns, just like I tried to explain to you, and both explaining how!

Uh, no they don't say that.. and the Fw 190 and the Spitfire and the Mustang all start with somewhat of an elliptical lift distribution BEFORE the turn and have an 'elliptical like' (more for Spit/less for Fw 190 and Mustang) lift distribution in the turn.

Nothing about G forces 'achieve' elliptical lift in turns, they (G forces) only tend to shift lift distribution based on aeroelastic effects.

Check it out with Gene - have him copy me on the reply.

Quote from Gene:

Aeroelasticity is simply a byproduct of flying and all aircraft experience it. The NACA 23000 series of airfoils have a harsh stall with no washout due to the fact they produce elliptical lift along the entire airfoil. That means with no washout the entire wing stalls at once. This is why the FW-190's wing is twisted to prevent it.

Soren, have you ever seen the behavior of a dog with fleas on his Butt? They go around in circles. Check out this canine behavior and see if you can find a human 'flea powder' for debates?

We just finished settling the fact that the Fw 190 cut out the outer 20% span's twist - they sacrificed tip control for aerodynamic efficiency in a straight line

The wing was left straight at the ends to gain the benefits of elliptical lift production at the tips making the tips more efficient and reducing induced drag production.

This is true - and the reason it lost tip control at nearly the same time it lost the rest of the wing lift.. So? It was a design feature in cruise and an design flaw in high speed/high angle of attack manuevers.

When aeroelasticity removes this twist then the FW-190 exhibits a harsh stall.

Actually I am not exactly sure that the issue was torsion (remove the twist) Soren, in fact I suspect bending because of the outboard shift to lift distribution - as I indicated several pages ago - but you wouldn't know the difference. Inboard (and aft) shift of Lift distribution from the wing stress axis usually results from Torsion as the CP tends to move aft. Outboard from bending

And by Lednicer

A wartime Focke Wulf report (Ref. 14) indicates that at higher loading conditions (i.e. when pulling more gs) elastic deformation of the Fw 190 out wing shifts the load distribution outboard. This would cause even more of the wing to reach its stalling lift coefficient simultaneous. Combined with the sharp stalling features of NACA 230xx airfoils, this would produce the harsh stall found in by Capt. Brown. A gentle stall would be evidenced by a more gradual progression of the 2D stall spanwise.

So who was it that was having problems with reading comprehension again Bill ??

I really am amused that you keep using my reference above in the Lednicer Report to rebut my rebuttal to this dopey statement from you - which started all this latest 'stuff'

Soren blurts - "However in the case of the 190 you will note that the wing twist was applied to such a degree as to provide elliptical lift distribution under G's (which btw is the reason for the violent departure), it was purposely done so to achieve the maximum 'e' factor and therefore L/D ratio in turns. Now ofcourse you wont see that on Lednicer's comparison as his simulation was done under 1 G, something you seem unable to grasp."

So, Lednicer (and I say) aeroelastic bending caused the outboard shift in lift distribution, combined with no twist in outer region of wing, which in turn resulted in the outboard chunk of the wing reaching critical stall at the same time..

and you say "wing twist was provided to such a degree as to provide elliptical lift distribution under G's (which btw is the reason for the violent departure, it was purposely done so as to achieve maximum 'e' factor and therfore L/D ratio in turns.. blah, blah, blah

This is a multiple choice test - you have a 50/50 shot.

Which explanation coincides with Gene/Lednicer and me - versus you?

Marcel · 05-20-2008, 02:37 PM

To Soren and Bill:

Not to try and be a moderator, but couldn't you at least ignore each other? These mud throwing from both sides gets really annoying. Or maybe start your own thread, so you can bash each other all day without bothering others with it.

drgondog · 05-20-2008, 02:54 PM

Quote:

Originally Posted by Marcel

To Soren and Bill:

Not to try and be a moderator, but couldn't you at least ignore each other? These mud throwing from both sides gets really annoying. Or maybe start your own thread, so you can bash each other all day without bothering others with it.

You are right.. it is consuming too much time going in circles..