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

[Hunter368]

Originally Posted by drgondog

Nah - I have enormous respect for Crumpp, and as I noted I AGREE with the comments contained. The reason I keep drawing Soren back to my Post 77 is I sate several of the same things - then go on to explain how aeroelasticity affects load distribution over a wing - to tie into the Lednicer speculation.

I like the 'Momma' analogy a lot. Momma said some comforting things to Soren, but he was confused regarding who was saying what, and maybe is still confused regarding how to put Momma's very good advice to help support him against that mean bully that didn't always say nice things to him.

Soren - I am ready to discuss why I said Aeroelasticty was more an art than a science in WWII. But first I want You to start by describing the analytical problems to be solved to get an accurate model of an airframe as a system.

Absent your understanding of That - you will be like a goose in a barnyard when I get into the what's and the Why's??

Your ball.

As I just noted I was more interested in what Soren said to Gene?

The Momma (made by kruska) comment that was made was not needed, all it did/does is create more bad blood between you and Soren when you responded to it. It was not witty or called for. Surely you see it for what it was, mud slinging.

I understand you will say Soren does his fair share of mud slinging also, but will no one take the high road between you?

Then responded to the email in a great way, with facts and questions. But the damage was done already.

[Soren]

I fear this will never be resovled as Bill seems unable to admit when he is wrong..

Oh and thanks for saying I basically don't know the difference between left & right Bill, that was definitely the way to go!

[Kurfürst]

... I wonder if the last couple of pages containing the Soren vs. Bill stuff could be moved to the Soren vs Bill thread..?

[Hunter368]

Originally Posted by Kurfürst

... I wonder if the last couple of pages containing the Soren vs. Bill stuff could be moved to the Soren vs Bill thread..?

It was closed.

[Kruska]

Hello Hunter 368,

I guess you didn’t get the message, Soren unfortunately didn’t get it either. My Momma post just pointed out that bringing in a third party doesn’t solve the problem since it is about Soren and drgondog who present opposing interpretations of their posts which are not relevant to their individual accounts towards a third party who isn’t even involved in the dispute regarding of interpretations of posted opinions by the other two parties.

So a confused Soren is now trying to back up his dispute with other participating posts.

Am I wrong? Well then I would have no problem to apologize to Soren, but what interpretation of my Momma post on your behalf makes you legible to call me a mud slinger?

Regards
Kruska

[Soren]

I am not confused at all Kruska (Why would you even say that ??), and bringing in an experts opinion is definitely not straying off topic.

Sometimes you unfortunately need two mouths to get the message across.

[Marcel]

Originally Posted by Hunter368

It was closed.

Nope, the other one is still open

[drgondog]

Originally Posted by Soren

Again the second mail in its entirety:




This is what I've been saying all along, which I think everyone following this thread can testify.

Now, for a little context - bring forward all the 'quotes'

Soren sez
And what do I know ? Well I know that aerolasticity was a very well known science before WW2, that the effects of aerolasticity is taken advantage of by a/c designers to improve a/c performance in certain flight envelopes, that the Spitfire didn't have an elliptical lift distribution, that the Bf-109 & Spitfire both turned allot better than the P-51, that the Fw-190 featured elliptical lift ditribution in turns. And most importantly I can prove it, Bill can't.


Before I go further, can Soren now state that the designers of Fw 190 wing fully understand aeroelasticty effect on the wing tip in High G turns - or were they just 'having fun' with those hotshot pilots and 'give em' a suprise in a Gunfight?

My Reply to that particular jewel earlier

Bill sez -Next - the Spitfire, with an eliptical wing, does not have a pure elliptical lift distribution, but a lot closer than the 51 and the Fw 190A and D.. I pointed out examples of the spanwise lift distribution presented in one of Lednicer's plots.

Next - to even the least knowledgable but enthusiastic studiers of the art of wing design, the twist at the tip for the wing chord is to ensure that the tip region (simply for you, the aileron area) of the wing stalls last, with stall starting inboard and moving out board. To those pilots on this forum that means when we screw up and lose ability to fly say, on final approach, we want to sink - not roll.

You are free to be you, Soren, and think it is all about giving the Fw 190 'elliptical lift' distribution in high G turns. You are equally free to 'prove your thesis' and now that you have said you can, please do not complain when I follow you around on this commitment

Very specifically - we do NOT design tip twist to develop 'elliptical' lift distribution as you posed for the Fw 190 a week or so ago. And last on this subject the twist is to SPECIFICALLY alter the chord angle of attack Downward so that the relative angle of attack in the outer wing doesn't stall when the inboard region reaches the stalling angle of attack.


T quote from Gene's email to you

I do know Bill. He is not only very knowledgeable but someone I consider a friend. It is very disappointing to hear that you two cannot get along discussing old airplanes.

I can certainly clarify what I meant however the two points do not seem to be related or at least I cannot see how they are related. The only thing in common is the term "elliptical lift distribution". Lednicer is referring to the cl/CL ratio which gives us a clue as to the wing efficiency. The analysis is made at 360Kts at 15,000 feet and is good for that condition. Wing efficiency will change with condition of flight and square wingtips can very easily be designed that equal elliptical wings. However they are designed to be that optimal for a specific condition of flight. For example at the Prmin point, L/Dmax, or Va would serve as a design point depending on what the performance the designer desired.

Since the Mustang and FW190 are designed to most efficient at one design point and the Spitfire has an elliptical wing which is efficient at all points, Lednicer's observation is correct in that the Spitfire probably has the most optimal of the three. Probably is used because the aerodynamic twist in the Spitfire wings in order to prevent the wing from stalling all at once reduces this efficiency. That too would be designed for an optimal point of performance.


Soren sez -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).

From Gene -This statement refers to the fact aeroelasticity removes the aerodynamic twist placing the airfoil sections at the same co-efficient of lift. The sections then reach CLmax all at the same time. When one side of our wing or the tips stall, the aircraft will drop a wing or if the stall is large enough, the aircraft will roll inverted. That is what Lednicer is saying. This was not a design feature. It is just an explanation for the differences in the FW190's stall behaviors.

To Summarize from my Post 77

Let's take these one at a time

From pages 550-551 - chapter Elements of Finite wing theory, "Principles of Ideal-Fluid Aerodynamics", Krishnamurty Karamcheti, Professor of Aeronautics and Astronautics- Stanford Univesity.. Published by John Wiley and Sons -1966

"To obtain an elliptic lift distribution on a (geometrically and aerodynamically) untwisted wing, the spanwise distribution of the chord should be elliptic"

Point 1. Elliptical Wing is the optimal planform for minimum Induced Drag
Point 2. Varying the tip ratio to approximately .4 will closely approach an Elliptical Wing as far as reducing the induced drag at the sacrifice of adding more weght (for same aspect ratio)
Point 3. The downwash corresponding to an elliptic lift distribution is a constant all along the span, further the rolling and yawing moments on such a wing are zero no matter how the chord, the angle of attack and the wing section are arranged.

Further, from 12:8-9 Spanwise Lift Distribution under Load "Supersonic and Subsonic Airplane Design" by Gerald Corning Professor Aeronautical Engineering Department - University of Maryland 1960

Point 4. The downwash corresponding to a trapezoidal wing planform varies along the span
Point 5. The spanwise lift coefficient for a trapezoidal wing planform changes with the downwash along the span.
Point 6. The G forces have bearing only on the elastic properties of the wing - and have nothing to do with lift distribution Unless and Until the wing twists or bends to change the relative angle of attack from 'no load' angle.
Point 7. The changes which tend to throw lift load Outboard are a function of bending rigidity, while the changes which tend to throw lift load Inboard are a function of torsional rigidity.

Therefore - pulling high G's seemed to affect the Fw 190 for two reasons (not known when designed) a.) aeroelastic bending of the Fw190 wing, moving the lift distribution outboard, and b.) not having twist in the outboard 20% of the span. As Lednicer quotes the LW report dated January 1944 you may presume he knows more about the German explanation than you do.


Make your own judgements..

[Kruska]

Hello Soren,

Maybe confused is the wrong word, maybe wringing for help-support describes it better. But anyway, please just disregard my post for the sake of a friendly continuation between our posts and opinions, okay

Regards
Kruska

[Hunter368]

Originally Posted by Kruska

Hello Hunter 368,

I guess you didn’t get the message, Soren unfortunately didn’t get it either. My Momma post just pointed out that bringing in a third party doesn’t solve the problem since it is about Soren and drgondog who present opposing interpretations of their posts which are not relevant to their individual accounts towards a third party who isn’t even involved in the dispute regarding of interpretations of posted opinions by the other two parties.

So a confused Soren is now trying to back up his dispute with other participating posts.

Am I wrong? Well then I would have no problem to apologize to Soren, but what interpretation of my Momma post on your behalf makes you legible to call me a mud slinger?

Regards
Kruska

Sorry you seem you also slightly misunderstood my post as much as I did yours.

1) Soren purposed using Crumpp who is very knowledgeable on the subject (more so then even Bill or Soren), Bill never opposed the idea at the time. Then you posted your Momma comment, which "perhaps" I (and Soren) slightly misunderstood. When Bill then made his comment about his Momma (which is what I called mud slinging by him not you), I thought he was now discrediting Crumpps opinion b/c it did not agree with his opinion. Which Bill clearly up also shortly after, agreeing with Crumpp.

As often happens with Soren and Bill, they talk past each other. Not sure if by accident or intentional.

In summary I was commenting about Bill not you. The only thing I said about your post was I thought it was not needed and just the problem worse between them. I did reread my comment and i see how you read into my comment what you thought. I worded it poorly, I meant to slip in Bill's name not yours. Sorry

[drgondog]

Originally Posted by Hunter368

The Momma (made by kruska) comment that was made was not needed, all it did/does is create more bad blood between you and Soren when you responded to it. It was not witty or called for. Surely you see it for what it was, mud slinging.

I understand you will say Soren does his fair share of mud slinging also, but will no one take the high road between you?

Then responded to the email in a great way, with facts and questions. But the damage was done already.

Hunter - go back to the thread by Soren requesting 'help - on his trying to decide about which rimfire rifle to buy - and note the tone I used in trying to help. Decide whether that was 'high ground' and cordial. I was absolutely taking high ground and trying to help him with experiences of my own.

Then go to the thread here, AFTER my posts of yesterday, where Soren posted Gene's email and view his attitude.

That's all I'm gonna say about 'high road'

[Hunter368]

Originally Posted by Kruska

Hello Soren,

Maybe confused is the wrong word, maybe wringing for help-support describes it better. But anyway, please just disregard my post for the sake of a friendly continuation between our posts and opinions, okay

Regards
Kruska

I feel Soren is perfectly valid bringing in experts opinion. After all Bill is questioning Soren's lack of real education in the field, so why wouldn't Soren bring in another expert to prove his point to Bill (and help prove his point to all of us). Bill is discrediting or qestioning Soren's knowledge in the field, so let Soren bring in someone that Bill does respect to help win the debate. Sounds like a smart idea to me.

Not "wringing for help-support", just a smart thing to do. After all Bill is playing the "education card" that Soren does not have, so Soren bringing in a expert is fair.

[Soren]

LoL, Bill quit it alright, just admit you were wrong for crying out loud!

You have clearly & openly claimed that the Fw-190 did NOT achieve elliptical lift distribution in turns, you were proven wrong first by me then by Gene.

[Hunter368]

Originally Posted by drgondog

Hunter - go back to the thread by Soren requesting 'help - on his trying to decide about which rimfire rifle to buy - and note the tone I used in trying to help. Decide whether that was 'high ground' and cordial. I was absolutely taking high ground and trying to help him with experiences of my own.

Then go to the thread here, AFTER my posts of yesterday, where Soren posted Gene's email and view his attitude.

That's all I'm gonna say about 'high road'

Believe me I know I know, I seen your posts on rimfire thread. I give you credit, but don't stop now.

Example: Syscom can be the most annoying person to debate with on the face of the planet, as many of us will agree (Syscom take that smile off your face as you read this ). I admit I have lost it on him a few times over the years, said things I should not have out of fustration. But to Syscom's credit he never (very very rarely anyways) fires back with anything but facts (facts in his opinion anyways LOL), he keeps his cool. I respect him for that.

[Soren]

Originally Posted by drgondog

Hunter - go back to the thread by Soren requesting 'help - on his trying to decide about which rimfire rifle to buy - and note the tone I used in trying to help. Decide whether that was 'high ground' and cordial. I was absolutely taking high ground and trying to help him with experiences of my own.

Which I appreciate Bill.

Then go to the thread here, AFTER my posts of yesterday, where Soren posted Gene's email and view his attitude.

I came across badly there Bill, I wasn't trying to gloat. But I'll apologize if that's how it came across, and since Hunter seems to agree it did then there you go.

That's all I'm gonna say about 'high road'

The problem is Bill you shift from high to low almost constantly. Remember YOU started this mess by provoking ME, YOU were the one wishing a fight. So I only see it as appropiate that you were the one to try and establish a bridge between you and I again.