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

[Soren]

I just will not let him skate on this subject of aero/structres when he makes so damn many mistakes - then insults the guy that disagrees with him - 'for not grasping the obvious'.

No mistakes made by me, you on other hand Bill, well lets just say you look lightly upon the facts.

 

[DerAdlerIstGelandet]

my name is not bill.anyway,did the 109 not have a tendancy to crash on take off or landing.perhaps only aces could handle this problem.there is no need to get narky if one believes or not whether the said a/c had these inherent design faults.yours,preacher.

No one is getting cranky here. I just asked you to explain yourself, because you said the 109 is going to crash on take off and landing. That implies that is going to do so all the time, which is not true.

If that were the case then the top aces would not have flown the aircraft. If that were the case it would not have been the most numerous fighter built.

If not properly handled, yes it could happen. Is it going to happen all the time? No. Did it happen an ungodly amount of times? No.

My advice to you, so that this problem does not arise again is to actually explain your posts instead of using one liners.

You could always look at it the other way. What was the Mk21 most likely to encounter? the 109K

Interesting little side note. A lot of people say that the problem with the 109 was because of its narrow track. pbfoot who has a 109E and a Spitfire readily available to him actualley went and measured them and the Spitfire's track was actually a bit narrower.

I tried being nice towards you Bill but that went right out the window when YOU starting throwing mud into my face because I misunderstood a computer generated pressure distribution illustration. You were the one who insisted on being rude and calling names, which in my book is childish prick like behavior - I thought you were smarter than that.

You do the same thing Soren. You are just blind to you own faults.

Now - it is your turn to present facts and references to support all of your points... but you 'skip' your turn usually so I'm holding my breath.

Education - Experience - and now References.

We are all waiting...

 

[Soren]

And from Gene (Crumpp):

"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.

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

 

[Soren]

You do the same thing Soren. You are just blind to you own faults.

So you claim atleast..

We are all waiting...

No need to wait, it has already been presented, read my new posts above..

 

[DerAdlerIstGelandet]

So you claim atleast..

And a majority of this forum as well.

No need to wait, it has already been presented, read my new posts above..

I do not see any actual proof with sources.

 

[drgondog]

Oh and next time read all of what Lednicer says in his article:

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

So, the above is what Lednicer said. Above is what I said and referenced in other sources

Below is your mangled context inserted in the above quote

[elliptical effect = entire wing generates lift at the same angle of attack]. This would cause even more of the wing to reach its stalling lift coefficient simultaneous.

For an untwisted wing, below critical Angle of Attack, your statement while true in THAT context, is irrelevant to the Fw 190 and irrelevant to this discussion.

"Combined with the sharp stalling features of NACA 23000 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. "

Do you really know what you just wrote? The CONTEXT of the 'sharp stalling features of the 230xx airfoils' combined with 'this would produce the harsh stall found 'in by' (what??) Capt Brown - is missing the important point referenced by Lednicer - namely that the Fw 190 spanwise lift distribution shifted outward due to elastic deformation of the wing.

Here is the entire quote that you selectively parsed as you always do.

"A wartime Focke Wulf report (Ref 14) indicates that at higher wing loading conditions (i.e. when pulling more gs) elastic deformation of the Fw 190 outer wing shifts the load distribution outward. This would cause more of the wing to reach its stalling lift coefficient simultaneously. Combined with the sharp stalling features of the NACA 230xx airfoils, this would produce the sharp stall found by Capt. Brown.

Hmmm.. you turn Bill!

I noted in my prior posts that you selectively quote stuff that you think supports your thesis, then reach deep (somewhere) and pull out wierd stuff and place it somewhere in the quote. You could Not have proved my point any better.

You really have no idea what you said about the elliptic wing, nor how it possibly could have helped make your point by inserting it (elliptic wing lift distribution statement) into the entire quote from Lednicer, while removing the key point I made about aeroelastic deformation as a root cause, combined with zero angle twist the last 20% of the Fw 190 span..

You don't understand what you are reading, and you don't know the context of airframe design considerations - which largely are "it depends" rather than "absolutes"

Soren, you make up stuff as you go.. I have this vision of Opus and Bill the Cat (or Lucy and Charlie Brown) talking about the Theory of Relativity every time you go theoretical on us.

 

[Soren]

And a majority of this forum as well.

That's a bold claim seeing how many members there are.

I do not see any actual proof with sources.

LoL! The first is directly from Lednicer's article!

 

[DerAdlerIstGelandet]

Soren, you make up stuff as you go.. I have this vision of Opus and Bill the Cat (or Lucy and Charlie Brown) talking about the Theory of Relativity every time you go theoretical on us.

That's a bold claim seeing how many members there are.

Seriously...

LoL! The first is directly from Lednicer's article!

For once...

 

[Soren]

Sorry but you can't wiggle yourself out of this one Bill!

Here it is DIRECTLY from the article:

So Bill what is a matter ? Are unable to read suddenly ?

 

[Soren]

And what Crumpp wrote (Going to dispute him as-well Bill ?):

"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.

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

 

[Soren]

Seriously...

What you have a poll or something hidden away which says this or what ?

I'm sure if it was really like you say I would've been contacted by others than you..

 

[drgondog]

And from Gene (Crumpp):

"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.

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

Gene is correct..Lednicer is correct.. that is why virtually ALL a/c have twist.

You think you have stumbled onto a fundamental 'aha'??

Having said this a.) All trapezoidal wings have somewhat of eliptical lift distribution, (take a look at plot in Lednicer Report that I pointed out to you many times) b.) the elliptical distribution survives through a range of angle of attack for the trapezoidal wing although downwash varies spanwise with no twist, .c) all elliptical wings have better elliptical lift distributions (take a look at the abovementioned Lednicer plot) , downwash is constant for no twist and d.) elliptical planform has and less induced drag than trapezoidal planform although a tip chord to root chord ratio of .4 will closely approach the elliptical.. as I said in the posts above.

Lednicer specifically cites the Fw 190 spanwise twist as ranging from 2+ degrees at root to zero at 81.5.. then constant from there to 100% (that would be tip root chord for you).

I'm not sure Gene recalls this tidbit in the Lednicer report - or he has information that Lednicer was wrong about the outer 20% where Lednicer cites 'no twist'.

 

[DerAdlerIstGelandet]

What you have a poll or something hidden away which says this or what ?

I'm sure if it was really like you say I would've been contacted by others than you..

No Soren the PM's sent to me by members of the forum because they are tired of the arrogant and insulting way you post tells me this.

 

[Soren]

Oh and I didn't put this in: "[elliptical effect = entire wing generates lift at the same angle of attack]. " I just copy pasted the qoute from another forum as I didn't want to write it down directly myself, but now I took a photo of it instead.

 

[Soren]

No Soren the PM's sent to me by members of the forum because they are tired of the arrogant and insulting way you post tells me this.

PM from who ?

 

[Soren]

Gene is correct..Lednicer is correct.. that is why virtually ALL a/c have twist.

You think you have stumbled onto a fundamental 'aha'??

Having said this a.) All trapezoidal wings have somewhat of eliptical lift distribution, (take a look at plot in Lednicer Report that I pointed out to you many times) b.) the elliptical distribution survives through a range of angle of attack for the trapezoidal wing although downwash varies spanwise with no twist, .c) all elliptical wings have better elliptical lift distributions (take a look at the abovementioned Lednicer plot) , downwash is constant for no twist and d.) elliptical planform has and less induced drag than trapezoidal planform although a tip chord to root chord ratio of .4 will closely approach the elliptical.. as I said in the posts above.

Lednicer specifically cites the Fw 190 spanwise twist as ranging from 2+ degrees at root to zero at 81.5.. then constant from there to 100% (that would be tip root chord for you).

I'm not sure Gene recalls this tidbit in the Lednicer report - or he has information that Lednicer was wrong about the outer 20% where Lednicer cites 'no twist'.

Gene has all the stuff there is on the 190, and so I trust him a heck of a lot more on this than you!

 

[DerAdlerIstGelandet]

PM from who ?

Soren over the last few years I have recieved lots of PM's from members of the forum addressing you. I am sure I am not the only moderator.

I have told you this on several occasions. There goes your selective reading again.

In addition to this, many members have called you out on it on numerous occasions. Bill is just the newest to this.

Believe it or not, I am not taking his side here. I am just tired of you. If he is the latest member to call you out then so be it.

 

[drgondog]

Sorry but you can't wiggle yourself out of this one Bill!

Here it is DIRECTLY from the article:

So Bill what is a matter ? Are unable to read suddenly ?

Lol! I invite you to slither back to post 77 for the precise reference to that quote.

I invite you to see how you changed the wording when you 'quoted it' as I explained a couple of posts above this reply.

No wiggle, it is EXACTLY what I Said and Mean.

Are we in a dual personality mode here Soren.. you post funny stuff, I rebut with source - you then use my references to 'prove your point - thinking you are Me'??

The point I made early, middle and long on the Fw 190 violent manuevering stall was a.) elastic deformation, b.) outward shift of lift distribution and c.) no twist in outer 20% to alleveiate a sudden and complete stall of the entire wing at nearly the same time.

What point do YOU want to make with this article quote from page 89?

 

[Soren]

Bill,

Lednicer Crumpp are saying the same thing:

By Gene:

Correct, however the harsh stall of the NACA 230xx is without twist. The reason for the twist was to improve stall characteristics. 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.

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

David Lednicer conducted a interesting CFD analysis of the Focke Wulf and these were his conclusions. It's the only reasonable explaination I have seen for the two contrasting stall behaviors of the Focke Wulf.

 

[Soren]

And in fear of repeating myself:

I didn't write this: "[elliptical effect = entire wing generates lift at the same angle of attack]. " I just copy pasted the qoute from another forum as I didn't want to write it down directly myself, so it stayed there because I didn't notice it right away, but now I took a photo of the orginal text instead (Which says what I've been saying all along)

Here's where it came from, in the guy called JG14_Josf's post:
A Complete Waste of Space